2301 ELECTRIC GOVERNOR FOR GENERATOR SET AND INDUSTRIAL ENGI Caterpillar

Service Procedures

Usage:

Introduction

The information in this section is a supplement to the Checks and Tests of the previous sections. This material is much more descriptive and detailed for the user who is less familiar with these systems. The Troubleshooting Section makes constant references to this section when more detailed information is necessary to complete a test.

Service Procedure Index For 2301 Electric Governor

A. Nonparallel Control (Standby Unit)

B. Parallel Control (Load Sharing)

C. Low Idle Speed Adjustment

D. Actuator Check Procedure

E. Linkage Calibration

F. Power Requirements

G. Speed Setting

H. Minimum Fuel Switch

J. Gain and Stability

K. Magnetic Pickup

L. Droop

M. Load Gain

N. De-Droop

P. Phasing

Q. Acceleration Rate

R. Droop or Isochronous Mode Switch

S. 2301 Bench Performance Check

T. 2301 Operating Conditions

U. Incompatibility of Multiple Load Sharing Control Units

V. 2301 Overvoltage Protection

W. Voltage Drop to 2301 Control During Cold Start Conditions

Procedure A

2301 Nonparallel Control (Standby Unit)

2301 NONPARALLEL CONTROL BOX (8N408 SHOWN)

WIRING DIAGRAM FOR 8N408 CONTROL

NOTE A: Lube oil Idle Switch maintains Low Idle speed until oil pressure closes switch. Another switch can be added in series for low speed control at the switchgear.

NOTE B: A 500 ohm (max.) remote speed setting potentiometer gives approximately 1% speed change per 20 ohms.

NOTE C: 20K DROOP potentiometer. Must be left open if not used.

NOTE D: Acceleration rate capacitor causes additional acceleration time of 2 seconds per 50 mfd. Must be left open if not used.

NOTE E: Shielded wires should be twisted pairs.

NOTE F: Ground battery negative to switchgear frame and neutral bus.

NOTE G: Install shielded cable directly from component to control box. Do not go through terminal points. Connect shields only at control box grounding stud.

NOTE H: Installed on engine by CTCo.

NOTE J: For speed range of magnetic pickup, see Magnetic Pickup Frequencies For Electric Governors in Service Procedure K.

Procedure B

2301 Parallel Control (Load Sharing)

2301 PARALLEL CONTROL BOX (8N409 SHOWN)

FIGURE 1 WIRING DIAGRAM FOR 2301 PARALLEL CONTROL (8N409)

NOTE A: When power is removed for service, open both positive (+) and negative (-) supply leads (terminal T25 when used and terminal T11 if not opened by auxiliary contacts). Prevent leads from making contact with ground or from shorting together if not connected through a switch.

NOTE B: Remove jumper between terminals T20 and T21 when remote speed potentiometer is used. A high quality 100 ohm, 10 turn potentiometer is recommended. A resistance of 100 ohms "rheostat connected" will give approximately ± 4% speed adjustment.

NOTE C: For actuators used in tandem (series) operation, connect as shown at bottom of Fig. 1. Put jumper across control terminals T17 and T28 when two actuators in series are used.

NOTE D: This control has inside burden resistors. These burden resistors must be connected across power source current transformers while unit is running to prevent the development of high voltage in the leads to these terminals.

NOTE E: When the circuit breaker to main bus closes, the contacts of the auxiliary circuit breaker must close pilot relay contacts at the same time. Since only one pilot relay contact is used with the time control, remove the pilot relay contact in line connected to T11.

NOTE F: For Isochronous control, connect paralleling lines directly to terminals T10 and T11. Make sure jumper is across terminals T26 and T27, and DROOP potentiometer is turned to maximum CCW. If Isoch-Droop switch is used, remove jumper from terminals T26 and T27.

NOTE G: For speed range of the magnetic pickup, see Magnetic Pickup Frequencies For Electric Governors in Service Procedure K.

NOTE H: With a balanced three phased load and a power factor of 1 (one), the current transformers should be wired in the correct potential leg, and must be phased at the 2301 Load Share Control as follows:

Phase 1 - Potential terminal T1 with respect to neutral in phase with CT terminals T4 to T5.

Phase 2 - Potential terminal T2 with respect to neutral in phase with CT terminals T6 to T7.

Phase 3 - Potential terminal T3 with respect to neutral in phase with CT terminals T8 to T9.

NOTE J: Install shielded cable directly from component to control box. Do not go through terminal points. Connect shields only at control box grounding stud.

NOTE K: Lube oil Idle Switch will maintain Low Idle speed until oil pressure increases enough to close switch. Another switch can be added in series for low speed control at the switchgear.

NOTE L: Optional shutdown switch may be connected to terminals T22 and T23 for remote shutdown.

NOTE M: Installed on engine by CTCo.

NOTE N: All outside wiring must be added by customer.

NOTE P: When supply voltage at terminals T12 and T13 changes more than 3 volts between units, and terminal T13 is common (negative ground) for all other units, connect terminal T25 to terminal T25 of all other units. See Service Procedure F.

NOTE R: Make the size of the power source current transformers so that, with generator at maximum current output, a 5A secondary current is made. The center tap (CT) burden is 6.5 VA per phase.

Actuator Output

Connect a wire from T16 to Pin B of actuator plug, and T17 to the actuator plug Pin A. Make sure that wires are not shorted in the actuator plug. For actuators used in tandem (series) operation, see bottom of Figure 1 for correct method of wiring together.

NOTE: The EG-3P and the EG-10P require a jumper across terminals C and D of the mating connector to the actuator (if pin type connector is used).

Procedure C

Low Idle Speed Adjustment

The Low Idle speed adjustment on the 2301 Control has an adjustment range from shutoff to 95% of Rated speed. The idle adjustment will not change the Rated speed setting.

1. Make the correct adjustment for Rated speed with a jumper installed across the Low Idle terminals of the 2301 Control.

2. Remove the idle jumper. Disconnect any external switch leads on the idle terminals. The engine speed should now decrease from Rated speed. If Low Idle is set at minimum fuel position, the engine will stop. Make an adjustment CW to increase Low Idle speed. After setting at correct speed, connect remote switch leads. Rated and Idle speed should not change.

3. The remote Idle Switch must have a positive connection across the contacts at low current flows. The requirements of the contacts are as follows:

* Sealed

* Corrosion resistant

* Wiping (self cleaning) type

* Plated

Any change in the resistance of the Idle Switch will cause a change to Rated speed.

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NOTICE

If the Rated speed setting is made while extra resistance is in the Idle Switch (in closed position), any shift of the resistance to a smaller value will now cause the Rated speed to increase above the setting. An engine that starts to overspeed (run out of control) must be stopped immediately to prevent any damage to the engine.

If the above condition is present, remove the wires from the Idle Switch terminals and start the engine. With the engine now running at Low Idle so that the oil pressure can close the switch contacts, measure the resistance across the terminals of the switch. If the resistance is more than 0.3 ohms, replace the switch.

Procedure D

Actuator Check Procedure

Installation

When actuator is mounted to base on the engine, be sure that correct alignment is made with the engine fuel linkage.

A gasket should be placed between the actuator and the base mounting pad. For vertically mounted actuators, be careful to not block the drain hole(s) next to the centering pilot of the base (see Figures 1 and 2). The oil that drains through the drive shaft bore must flow freely to the sump. The splined drive shaft must fit into the drive with a free, slip fit; no tightness is permitted. The vertically mounted actuator must drop onto the mounting pad of its own weight without applying force.

Fig. 1 EG-10PC ACTUATOR

The actuator gets its oil supply from a sump in the mounting base. The engine overflows the sump (from the engine lube circuit) through an orifice that meters flow. The sump can be checked for fill level with the actuator removed. Cranking the engine will not make any oil flow at the actuator oil supply port. The actuator base gasket must not permit air leakage into the supply port.

Fig. 2 EG-3PC ACTUATOR

Fig. 3 CANNON-TYPE CONNECTOR

Fig. 4 LATER EG-3PC ACTUATOR WITH PIGTAIL-TYPE CONNECTION

A cannon-type connector is supplied with most 2301 Governor Drive Groups. A jumper wire connects C and D of the mating connector to the actuator (see View A-A in Fig. 3). Later EG-3PC Actuators (1W9841 and 1W9842) do not use the cannon-type connector.

The connectors used with the earlier actuator assembly must be removed from the wiring on the engine. The pigtail connection from the later actuator assembly can be made to wiring on the engine with two of the wires splices in the 1P2305 Electrical Terminal Assortment Kit. If these splices are used, put a 5P6009 Heat Shrinkable Tube over the splices for insulation.

If desired, connectors from the 6V3000 Sure Seal Electrical Connector Kit can be installed on the actuator assembly and engine wiring. For instructions on the use of this kit, see Special Instruction, Form SMHS7531.

The colors of the wires on some of the later actuator assemblies may be different. Some actuator assemblies will have purple and red wires. The purple wire is positive (+) and the red wire is negative (-). Other actuator assemblies may have red and black wires. On these, the red wire is positive (+) and the black wire is negative (-).

The engine fuel linkage must be free of binding and without backlash. If there is a collapsible member (permits compression) on the linkage, be sure the spring does not yield each time the actuator moves the linkage rapidly.

Actuator Troubleshooting

1. The 2301 Electric Governor Control must produce voltage at the lead terminals for actuator during engine cranking and operation. This voltage should be more than 4 volts during cranking. If correct voltage is present and actuator shaft does not have movement, stop the engine and disconnect actuator leads at 2301 Control. Check the resistance between leads. It should be between 30 and 40 ohms.

Disconnect the wiring connector from the actuator.

a. Put a jumper across pins C and D (on actuator). Measure the actuator coil resistance across pins A and B. It should be between 30 and 40 ohms. High resistance or an open circuit is an indication of a bad actuator.

NOTE: Later EG-3PC Actuators use only pigtail. The jumper is not necessary for this type connection.

Fig. 5 RESISTANCE MEASUREMENT OF ACTUATOR COIL

b. Measure the resistance of each lead between socket A and 2301 Control (+) actuator terminal (T17 or T6), and between socket B and (-) actuator terminal (T16 or T5) on 2301 Control. Repair the lead if resistance is more than 1 ohm. Check the fit of actuator pin to mating connector for a positive connection. Loose or corroded connections should be repaired or replacement made.

2. Connect the actuator leads again. Disconnect fuel linkage from the actuator lever. Operate linkage manually to feel for binding or too much effort (force). Repair any linkage binding. If effort seems too high, measure force requirement of linkage for reference to actuator work effort (see Actuator Specifications for work effort available). If linkage effort is more than actuator specification, repair the linkage. If linkage effort is acceptable, install the linkage back to actuator lever. Remove pressure tap plug from actuator and install 6V2044 Pressure Gauge (See Figures 6 and 7). Crank the engine and read the oil pressure (see chart Electric Governor Actuator Specifications).

Fig. 6 EG-10PC ACTUATOR (1/4 NPTF PRESSURE TAP)

Fig. 7 EG-3PC ACTUATOR (1/8 NPTF PRESSURE TAP)

a. If actuator fails to produce any effort in the FUEL ON direction, or there is no oil pressure, remove the actuator. Crank engine to see if there is drive rotation. Repair engine if drive does not rotate. Inspect drive spline connection for wear or shearing. Replace as necessary. Inspect actuator sump in engine for fill level. If level is low, clear plugged oil fill orifice in engine. Verify oil flow into sump during engine cranking.

b. If actuator oil pressure is low or pulses, inspect actuator base for any indication of air leakage into oil supply port, such as oil leakage at base gasket. Remove the actuator, inspect gasket mounting faces for burrs or debris which may prevent correct sealing of gasket interface. Crank the engine, inspect engine actuator sump for constant fill. Clear oil supply to sump if oil flow needs improvement.

c. Install the actuator again, and install linkage to the actuator. Crank the engine and measure the oil pressure. If oil pressure is still low, replace the actuator.

Actuator Adjustment

Do not make any internal adjustments to the Woodward EG-3PC or the EG-10PC Actuators. The only adjustment to be made is with the compensation needle valve.

The needle valve (see illustration) is used to adjust stability (CW slows engine response; CCW increases engine response). The needle valve is factory set at two turns OUT (CCW) from the closed position. If adjustment is necessary, use the procedure that follows:

1. With the engine running at normal operating temperature, make an adjustment to the 2301 Governor GAIN and STABILITY controls to get acceptable engine performance and stability. See Service Procedure J.

2. Stop the engine and let it cool down to ambient temperature.

3. Now restart the engine. If the speed is unstable at start-up, turn the needle valve IN (CW) to slow actuator response (increase stability).

NOTE: Do not completely close needle valve setting with the engine running. The typical setting is 3/4 to 2 turns open (CCW) from the closed (all the way IN) position.

Procedure E

Linkage Calibration

1. Verify that the levers on actuator and fuel control linkage are the correct length.

2. Inspect the rod ends. Rod end replacement should be made when side to side movement of ball (due to wear) will let ball face become flush with body sides.

ROD END

3. Install levers to actuator and fuel linkage at the correct angle. Fuel linkage must not bind at any position in travel range.

4. Make adjustment of linkage to fit levers. Verify that linkage will now move to shutoff and maximum fuel positions.

5. Run the engine at High Idle and measure the actuator amperage. All vertically mounted actuators should have 50 ma at High Idle; all horizontally mounted actuators have 81 ma at High Idle (except 3500 series engines). The 3500 series engine horizontally mounted actuator should have 50 ma at High Idle. Make an adjustment of the linkage from the actuator to the fuel system to get this operating position. Make linkage connecting rod longer or shorter by 1/2 turn adjustments until correct actuator amperage is available. Actuators that can not operate at the amperage specified may not permit maximum fuel position for highly rated engines. These actuators should be returned to the factory for recalibration.

NOTE: See Service Manual for a specific engine or see Special Instruction SMHS7188 for the correct linkage geometry (lengths and angles).

Procedure F

2301 Power Requirements

The 2301 Control requires a voltage source of 20 to 40 VDC for power to operate. Provide a battery charger to maintain a stable DC supply voltage if a battery is used for operating power.

Nonparallel (Standby) Unit

Electrical Connections

See wiring diagram in Service Procedure A for nonparallel wiring connections. The information that follows applies to the 8271-464, 8271-465, 8271-425 and 8271-692 Speed Controls. For other Woodward part numbers, the wiring diagram for that specific control should be used.

Static Checks

Energize (activate) the speed control by connecting DC power to T1 (-) and T2 (+). Do not start engine until the static checks that follow are completed.

Check 1. Regulated Power Supply

A. Check voltage across terminals T6 (+) and T15 (-) for 8.5 ± 1 VDC.

1. If voltage across T6 and T15 is zero, check voltage across terminals T1 (-) and T2 (+). If less than 20 VDC, find and correct the input voltage problem (i.e., bad connections, too much resistance, low battery output).

2. If voltage across T6 and T15 is still not 8.5 ± 1 VDC, remove all wires from control (except at terminals T1 and T2) and measure the voltage again at T6 (+) and T15 (-).

3. If measured voltage is now 8.5 ± 1 VDC, then the problem is in the wiring that was removed. If the voltage is still outside the 8.5 ± 1 VDC range, the speed control is bad. Make a replacement of the speed control.

Check 2. Amplifier Output Voltage

A. Install the wires again (if removed) to terminals T5 thru T16. Check across T6 (+) and T5 (-) for zero VDC. If voltage is not zero:

1. Visually check that failsafe circuit (terminals T3 & T4) is not defeated. See the chart for correct wiring of different 2301 Controls.

2. Check that actuator (or 35 ohm load) is connected to terminals T5 and T6.

NOTE: The actuator or a 35 ohm, 10 watt load must be connected across terminals T5 and T6.

B. Defeat the failsafe circuit using terminals T3 and T4 (see chart at A.1. for correct method). The voltage across T6 and T5 should now increase to 7 ± 1 VDC.

1. If voltage is not 7 ± 1 VDC at T6 and T5, check across T3 and T4 for zero volts. If voltage is not zero, the jumper is not effective and must be fixed. If voltage is zero, check for voltage at T6 and T5.

2. If voltage at T6 and T5 is still not in 7 ± 1 VDC range, turn the power off and remove actuator wire at T6. Now measure the resistance from the end of the removed wire to terminal T5 (should be 35 ± 5 ohms). If the resistance is low, be sure that the optional actuator diode (if used) is not causing a wrong reading.

3. If ohm reading was correct, connect the actuator wire back to T6 and remove all wires from terminals T7 thru T16. Measure the voltage again across terminals T6 and T5.

4. If the voltage is now 7 ± 1 VDC, the problem is in the removed wiring. If the voltage is still not in the 7 ± 1 VDC range, then the speed control has a defect. Make a replacement of the speed control.

NOTE: Failsafe circuit must be activated again before engine is started.

Parallel (Load Share) Unit

High Voltage Selector (Optional)

These 2301 Controls contain a high voltage selector that makes a selection of the highest battery voltage of the paralleled controls for improved load sharing. Operation of the high voltage selector may be used only with the controls that follow (and terminal 13 of the controls must be negative):

For example, a system has controls with part numbers 8271-422, 8290-009 and 8271-308. The 8271-422 and 8290-009 controls should have a common wire that connects T25 of one control to T25 of the other control. Terminal T25 of 8271-308 control should not be connected.

Static Checks

Energize (activate) the 2301 Control by connecting power to T12 (+) and T13 (-). DO NOT START ENGINE until the static checks that follow are completed.

NOTE: The actuator or a 35 ohms, 10 watt load must be connected across T16 and T17.

1. Check across terminals T28 (+) and T23 (-) for 10.0 ± 1 VDC.

2. Check across terminals T17 (+) and T16 (-) for 0 VDC with terminals T29 and T30 jumpered (failsafe circuit activated). Now remove jumper (failsafe circuit is defeated). This voltage measurement should now increase to approximately 6 VDC.

3. Check the voltage across terminals T11 (+) and T13 (-). It must be approximately 10 VDC. If voltage is near zero, check that neither paralleling line is connected to battery negative.

NOTE: Failsafe circuit must be activated (jumper installed) again before engine is started.

Procedure G

Speed Setting

Speed Setting Adjustment

Set RATED SPEED potentiometer to Rated speed while external speed trim (if used) is set at center position.

Remote Speed Trim/Standby Unit

With terminals T11 and T12 factory jumpered, an internal potentiometer sets the speed. For remote speed trim, remove the jumper and connect a potentiometer (250 ohms maximum) as shown on wiring diagram (Service Procedure A). Speed change is 1% per 20 ohms. External wiring must be shielded.

Remote Speed Trim/Load Share Unit

For external speed trim, remove the jumper wire from T20 and T21. Connect a 100 ohm potentiometer to T20 and T21 as shown in wiring diagram (Service Procedure B). This potentiometer gives approximately ± 4% speed adjustment. External wiring must be shielded.

Procedure H

Minimum Fuel Switch

2301 Parallel (Load Share) Unit Only

Connect T22 and T23 to a switch or relay contacts as shown in wiring diagram (Service Procedure B). Shielded wire must be used.

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NOTICE

Do not use the Minimum Fuel switch for any emergency engine shutdown.

The minimum fuel switch can be used as an optional method for normal shutdown. Caterpillar does not recommend the use of this switch.

Procedure J

Gain And Stability

Gain and Stability Adjustment

The reason for the GAIN and STABILITY adjustment is to get the best stability from the engine output.

To get the best performance, set the GAIN potentiometer at the maximum stable CW (clockwise) position. In some cases the GAIN must be decreased slightly to make sure stability is available for the most variable conditions.

ENGINE PERFORMANCE CURVES

Connect a DC voltmeter to terminals T16 (-) and T17 (+) (actuator voltage) on Load Share Control, or terminals T5 (-) and T6 (+) on Standby Control.

Increased gain causes faster transient response. To get a faster response, increase GAIN potentiometer CW to a slightly unstable condition (which is best seen on the voltmeter). Adjust the STABILITY potentiometer either direction as necessary for acceptable stability. Step load the engine, or bump (move slightly) the fuel control linkage to check stability. Now make more adjustment to STABILITY as necessary. If you can not get stability for a transient by the STABILITY adjustment, decrease the GAIN (unless stability is a slow hunt, in which case, GAIN must be increased).

Procedure K

Magnetic Pickup

The magnetic pickup is used to sense engine speed. It is a single-pole, permanent-magnet generator made up of a coil of wire wound around a permanent magnet pole (Figure 1).

Figure 1 SCHEMATIC OF MAGNETIC PICKUP

With the magnet placed close to the gear teeth, an AC voltage is generated as the gear teeth cut through the magnetic field. This output is proportional to engine speed, and is sent to the 2301 Control. The speed sensor in the control box is sensitive only to the frequency of the magnetic pickup input, so that the amount of the magnetic pickup voltage is important only in that the level is enough to activate the speed sensor circuits. When connected to the control, about 1 VAC is the minimum usable level. Voltages up to 50 volts at Rated speed are often generated, depending on the gap between the gear and magnetic pickup pole piece. This clearance is normally 0.56 to 0.85 mm (.022 to .033 in.).

For field installation, this gap may be set by turning pickup into threads until magnet is against the gear tooth while the engine is stopped. Now back pickup out 1/2turn ± 30°, and tighten locknut to 70 ± 14 N·m (50 ± 10 lb. ft.).

Two magnetic pickups are currently being used with Caterpillar products; one with 2301 Systems and another with the electronic overspeed contactors. The basic difference between the two is that the 2301 pickup is used to connect the control box to the pickup by a continuous, shielded wire. Although this wire must be installed and soldered in the field, a junction box is not required.

The electronic overspeed pickup can also be used with the 2301 Governor. This pickup has an attached 2.4 m (8.0 ft.) shielded lead which is terminated by three spring spade connectors. A shielded wire must then be installed from the termination of the pickup wire to the 2301 Control Panel.

If the 2301 Governor is used on the same engine with the electronic overspeed switch, the single electronic overspeed switch pickup should be used for both systems to prevent possible problems with wire splicing (fastened together) in the field (except 3500 engines).

NOTE: If the shield of the magnetic pickup cable is connected to the shield terminal on the overspeed switch, this connection grounds the shield. With this arrangement, the shield must not be grounded to the 2301 Control panel.

The 3500 Series engines use two magnetic pickups, one for the 2301 Governor and another separate pickup for the electronic speed switch.

Magnetic Pickup Check

Check for more than 1.0 Vrms maximum at Rated speed with magnetic pickup wiring connected to 2301 Control.

1.0 VAC rms minimum,including cranking.

Troubleshooting the Magnetic Pickup

1. Disconnect the pickup leads and check the resistance between these leads (with an ohmmeter) for 150 to 250 ohms.

2. Check between the pickup case and these leads with ohmmeter for almost infinite resistance.

3. Start the engine and control the speed manually, or block the throttle. Check the pickup leads with a high impedance, AC voltmeter for 10 to 20 volts rms.

4. Connect the pickup leads again and check at magnetic pickup input terminals T18 and T19 (T7 & T8, Standby Unit) for a minimum 1.0 volts rms at the lowest controlling speed.

5. If voltage is low, check the clearance between gear and pickup. Inspect the pickup for outside damage. If defect is found, make a replacement of the magnetic pickup.

Magnetic Pickup Frequencies (Hz) for Electronic Governors

NOTE: Frequency control range of 2301 Controls (8N408, 8N409, 8N6729 and 8N6728) is 1800 to 5400 Hz. Frequency control range of 2301 Controls (4W5392, 4W5395, 4W5393 and 4W5394) is 2000 to 6000 Hz.

For frequencies of Rated Speeds not shown in chart, calculate with the formula that follows:

Magnetic Pickup Frequency

The 2301 Control has a Woodward part number with or without an alphabetical prefix that is the specification of the correct speed range. Choose a range that includes the magnetic pickup frequency at Rated speed. See the chart that follows for applications of all part numbers.

The speed range can be changed by movement of the jumper on the bottom of the PCB. This operation requires that the DC supply voltage be disconnected from the control, and a battery powered soldering iron be used.

FIGURE 2 PRINTED CIRCUIT BOARD (PCB) JUMPER LOCATION

FIGURE 3 PRINTED CIRCUIT BOARD (PCB) JUMPER LOCATION

If a battery powered soldering iron is not available, an AC powered iron can be used, but the tip must be jumpered to terminal T15.

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NOTICE

Failure to use above procedure can cause damage to the 2301 Control.

Procedure L

Droop

Droop Adjustment

This adjustment is only necessary for droop operation. The DROOP control sets the amount of speed regulation for the engine. (Only required when paralleling with utility bus or other larger units using hydra-mechanical governors). Since speed regulation is a function of load or power delivered, the DROOP function makes a reduction to the engine speed setting with an increase in load. The percent of speed droop is the difference between engine speed at No Load and engine speed at Full Load, and is calculated as follows:

Normally the percent of Droop is known, and the correction needed is the amount to increase the No Load setting. In this case, the No Load setting is calculated as follows:

(100% + % of Droop) X Full Load Setting = No Load Setting

For example:

(100 + 3%) X 60 Hz = 61.8 Hz

NOTE: If only 50% loading is possible, a No Load setting of 60.9 Hz would be an indication of 3% Droop as shown in the illustration for Droop Adjustment.

DROOP ADJUSTMENT

Setting DROOP On System Operating Into A Commercial Bus

1. With the unit off the line, run the engine. Set the speed to 60 Hz (No Load setting). Mark this position.

2. Set RATED SPEED potentiometer setting above the 60 Hz reference by the percent Droop required. (For example, 3% Droop would mean raising the speed to 61.8 Hz.) Mark this potentiometer position, and return potentiometer to 60 Hz.

3. Turn the DROOP potentiometer fully CW (maximum Droop), and set the external Mode Switch to DROOP.

4. Bring the unit on the line.

5. Return the RATED SPEED potentiometer to the point marked in Step 2.

6. Now make adjustment to DROOP potentiometer in CCW direction (decreasing Droop) until Full Load (Rated) is reached.

Setting DROOP For An Isolated Load

1. Run the engine and set the Mode Switch to DROOP position.

2. With the load removed from the engine, set RATED SPEED potentiometer to the No Load speed calculated (for 3% Droop, speed setting would be 61.8 Hz).

3. Apply 100% of the load to the engine.

4. With the engine fully loaded, make an adjustment to the DROOP potentiometer until 60 Hz is reached.

Procedure M

Load Gain

Load Gain Adjustment

NOTE: STABILITY and GAIN potentiometers must be correctly adjusted before starting this procedure. See Service Procedure J.

1. Put the probes of a voltmeter in the LOAD SIGNAL jacks (located on face of control).

2. Run the engine in single unit operation until the coolant temperature is normal.

3. Put a full load on the generator. Adjust LOAD GAIN potentiometer until the load signal reading on the voltmeter is 8 VDC. If it is not possible to put a full load on the generator, keep the ratio between the load and the voltage signal constant. For example: if the load on the generator is 1/2 of its rated capacity, adjust the LOAD GAIN potentiometer to get a load signal of 4 VDC.

4. Do Steps 1, 2 and 3 to all the units in the system. The load signal for each unit in the system must be the same.

5. If any of the units in the system have stability problems at this LOAD GAIN setting, decrease the setting for each unit a small amount. Keep the load signal for each unit in the system the same.

6. If the load signal at Full Load is decreased to 3 VDC in Step 5 and the system still has a stability problem, do Steps 7, 8 and 9.

NOTE: The need for reduction of this setting to as low as 3 VDC is caused by very poor system dynamics. With this condition, Caterpillar Tractor Company should be contacted for their recommendations.

7. Parallel all of the units in the system at No Load.

8. If the system has instability, turn the STABILITY potentiometer of each unit one mark counterclockwise (CCW). Do this until the system has stability.

9. Put a load on the system. If the system still does not have stability, turn the STABILITY potentiometer of each unit one mark CCW. Do this until the system has stability.

Procedure N

De-Droop

De-Droop Adjustment

The DE-DROOP adjustment is the removal of any Droop that results from component tolerances in the system.

1. Set the Mode Switch to Isochronous operation (or install jumper across terminals T26 and T27).

2. Run the engine in single unit operation until the coolant temperature is normal.

3. With no load on the system, run the engine at full speed (High Idle) and check rpm. If adjustment is necessary, use RATED SPEED potentiometer to set engine to specified Full Load (Rated) rpm.

4. Now apply 100% load to the engine.

5. If rpm is now lower than specified Full Load rpm, use the DE-DROOP potentiometer to return the engine to the correct rpm.

Procedure P

Phasing

Current Transformer Phasing Check

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NOTICE

Before starting phasing check, be sure potential connections for phases A, B and C correspond to control terminals 1, 2 and 3.

1. Connect DC voltmeter leads to the LOAD SIGNAL test jacks on the control. Be sure polarity is correct.

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Never disconnect current transformers from the burden resistors (terminals 4 through 9) when the engine is running. The current transformers can develop very high voltages when open circuited with unit loaded, and the result can be serious injury or death to personnel.

2. Check the phase wiring by shorting, for a moment, the Phase A current transformer (CT) secondary terminals (T4 to T5). The load signal voltage should drop by 1/3if the load is evenly divided between the three phases. Repeat this procedure for Phase B (T6 to T7) and Phase C (T8 to T9), one phase at a time.

Most paralleling problems are caused by not wiring correctly the three-phase current and potential inputs. Common errors include either wiring the voltage of one phase with the current of another phase, or wiring the transformers backward.

If the load signal voltage dropped by 1/3 for each phase, the phasing is correct and PHASING PROCEDURE is not necessary. Proceed to LOAD GAIN ADJUSTMENT.

If the load signal for an individual phase did not drop by 1/3, or if parallel operation is not correct, proceed to PHASING PROCEDURE.

Phasing Procedure

1. Turn LOAD GAIN potentiometer to its center position.

2. Add a constant load to the generator. If it is not possible to use a load bank for the constant load, or if the load has variation, use two voltmeters to make measurement of the LOAD GAIN voltage and CT input voltage at the same time.

3. Short out CT inputs of Phase B (T6 to T7) and Phase C (T8 to T9). It is important that the jumpers be no longer than 101.6 mm (4.0 in.), and are 18 ga. or heavier. Jumper terminal connections must be of low resistance (alligator clips can be used).

4. Read Phase A (T4 to T5) CT input in Vrms.

5. Read the Load Signal voltage at the LOAD SIGNAL jacks.

6. Find the ratio "R" where

7. If R = +0.95, Phase A is correctly wired.

8. If R = -0.95, Phase A (T4 to T5) CT polarity is reversed.

9. If R =- 0.5, Phase A (T4 to T5) CT is interchanged with Phase B or Phase C. ^*

10. If R = +0.5, Phase A (T4 to T5) CT is interchanged with Phase B or Phase C, and Phase B (T6 to T7) or Phase C (T8 to T9) CT is reversed. ^*

^*It cannot be determined which phase is interchanged with Phase A by testing only Phase A. Repeating the above tests using Phase B and Phase C should give an indication which phase is interchanged with Phase A. If all phases give the same result (i.e., number 9 above), then the system should be shut down and CT inputs rotated by one position (i.e., Phases A to B, Phases B to C and Phases C to A). If the same results are again repeated, shut the system down and again rotate the CT inputs one position.

EXAMPLE 1: Phase A CT connection reversed.

1. With the unit loaded, turn LOAD GAIN potentiometer to center position.

2. Short out Phase B (T6 to T7) and Phase C (T8 to T9) CT inputs.

3. Read Phase A CT input in Vrms. Measurement between terminals T4 and T5 gives 1.25 (VAC).

4. Read the Load Signal voltage at the test jacks and check the polarity markings (V = -1.19 VDC).

6. Since R = -0.95, we know that the CT connections to terminals T4 and T5 are reversed. Shut the engine down, then disconnect and reverse the wires.

EXAMPLE 2: Phase A interchanged with Phase C, Phase C reversed.

1. With the unit loaded, turn LOAD GAIN potentiometer to center position.

2. Short out Phase B (T6 to T7) and Phase C (T8 to T9) CT inputs.

3. Read Phase A CT input in Vrms. (Measurement between terminals T4 and T5 gives V = 1.25 VAC).

4. Read the Load Signal voltage at the test jacks and check the polarity markings (V = +0.62 VDC).

6. Phase A CT is interchanged with Phase B or Phase C, and Phase B or Phase C CT is reversed.

7. Short out Phase A and Phase C CT inputs (attach a jumper between terminals T4 and T5, and T8 and T9). Open jumper between terminals T6 and T7.

8. Read Phase B CT input in Vrms, with measurement between terminals T6 and T7 (V = 1.25 V).

9. Read the Load Signal voltage at the test jacks and check the polarity markings (V = +1.18 VDC).

This is an indication that Phase B is correctly connected. We are now sure that Phase A and Phase C are interchanged. We also know that Phase C phasing is reversed because Phase B was found to be correct.

11. Stop the engine and reverse the phasing of Phase C CT (T8 and T9). Then interchange Phase A and C CT connections. Be sure to maintain correct phasing once this phasing procedure is complete.

Procedure Q

Acceleration Rate

Ramp Switch (Parallel Unit)

Connect a SPST switch between terminals T14 and T15. Oil pressure is normally used to close the Ramp switch. External wiring must be shielded. With T14 and T15 open, only Low Idle speed is selected. When T14 and T15 is closed, a ramp to Rated speed is started. If Low Idle speed is not used, T14 and T15 must be jumpered.

Ramp Time Adjustment (Parallel Unit)

Adjust the RAMP TIME to get the desired rate of engine acceleration to Rated speed with minimum overshoot. Do this by trial and error. Start first at center position of RAMP TIME potentiometer, and then work back CCW until the unit ramps as fast as desired.

Acceleration Control (Standby Unit)

An optional acceleration rate control capacitor may be added at terminals T15 and T16. The capacitor will add two seconds of acceleration time (from Low Idle to Rated speed) for every 50 mfd increase, with a maximum increase of 200 mfd. Leave terminals open if not used.

Procedure R

Droop Or Isochronous Mode Switch

Standby Unit

Droop operation can be obtained by switching or installing a 20 kilohm potentiometer to terminals T13, T14 and T15. T13, T14 and T15 must be open for Isochronous operation. A TTSP switch on these terminals will permit Droop or Isochronous Mode selection.

Parallel Unit

If a Mode switch at T26 and T27 is used in place of the factory jumper, connect it to a switch or relay as shown in the wiring schematic (Service Procedure B). When the contacts at T26 and T27 are open for Droop operation, the positive paralleling line (T10) is also open. These lines must be shielded, and the shields must be tied to chassis ground at the control end only.

NOTE: Droop operation is required when paralleling with an infinite bus, or with other units not having electric governors.

Procedure S

2301 Bench Performance Check

This section contains a bench performance check and a troubleshooting guide. Check all the terminal screws regularly for tightness. Check the condition of the wiring and shields. Keep the terminal blocks clean.

The fastest way to learn if a 2301 Control has a defect is to exchange it with a spare.

Standby Unit

The following procedure is similar to field operating conditions for the 2301 Speed Control. Before the bench check is started, visually check the chassis, terminal block and printed circuit board for damage.

1. Connect a 24 or 32 VDC source to T1 (-) and T2 (+).

2. Connect a closed SPST switch between T9 and T10. This is the Idle/Rated switch.

3. Connect a 35 ohm, 10 watt resistor between T6 and T5. This is similar to the actuator coil.

4. Connect an AC signal generator to T7 and T8. This is similar to the magnetic pickup.

5. Turn RATED SPEED potentiometer fully CW.

6. Connect a DC voltmeter between T5 (-) and T6 (+) to read actuator voltage.

7. Turn on the power supply.

8. Turn on the signal generator. Set it to the Rated magnetic pickup frequency of unit under test. Set the output level between 2 and 6 Vrms.

9. Actuator voltage should be approximately 7 VDC.

10. Slowly turn the RATED SPEED potentiometer CCW until the actuator voltage slowly starts to decrease toward zero. This means that the Rated Speed setting is now just below the magnetic pickup signal frequency.

11. Decrease the signal generator frequency until the actuator voltage starts to increase. This is similar to a decrease in engine speed, and is the normal actuator control response to this speed reduction.

12. Open the Idle/Rated switch at T9 and T10. The actuator voltage should now drop to zero. Now lower the signal generator frequency below Low Idle speed. When the frequency is less than Low Idle, voltage should increase to about 7 VDC.

13. Close the Idle/Rated switch. The actuator voltage should now stay at maximum voltage (approximately 7 VDC).

14. Turn off the signal generator. The actuator voltage now should drop to zero, which is proof that the failsafe circuit is working (activated).

15. Turn on the signal generator and change the signal generator frequency from below Rated to above Rated frequency. This will be the same as an increase in engine speed. The actuator voltage should now decrease toward zero. Move the frequency below Rated speed, and actuator voltage should now increase.

Parallel Unit

The following procedure is similar to field operating conditions for the 2301 Load Share Control. Before the bench check is started, visually check the chassis, terminal block and printed circuit board for damage.

NOTE: The load sensing circuitry is not included in this procedure because of the 3 phase inputs required. That check must be made with actual load conditions.

1. Connect a 24 or 32 VDC source to T12 (+) and T13 (-).

2. Connect a closed SPST switch between T14 and T15 (RAMP switch).

3. Connect a 35 ohm, 10 watt resistor between T16 and T17. This will be the same as the actuator coil.

4. Connect an AC signal generator to T18 and T19. This is similar to the magnetic pickup.

5. Connect an open SPST switch between T22 and T23. This is similar to the Minimum Fuel switch.

6. Turn RATED SPEED potentiometer fully CW.

7. Connect a DC voltmeter between T16 (-) and T17 (+) to read actuator voltage.

8. Turn on the power supply.

9. Turn on the signal generator. Set it to the same frequency as the Rated magnetic pickup frequency of unit under test (at 2 to 6 Vrms).

10. The actuator voltage should be approximately 6 VDC.

11. Slowly turn the RATED SPEED potentiometer CCW until the actuator voltage starts to decrease slowly toward zero. This means that the speed setting is now just below the Rated speed (frequency) signal.

12. Decrease the signal generator frequency until the actuator voltage starts to increase. This is similar to a decrease in engine speed, and is the normal actuator control response.

13. Open the RAMP switch at T14 and T15. The actuator voltage should now drop to zero until the signal generator is set to slightly less than the Low Idle frequency, where the voltage will begin to increase.

14. Close the RAMP switch. The actuator voltage should now increase to maximum voltage, approximately 6 VDC.

15. Turn off the signal generator. If the actuator voltage now drops to zero, this is an indication that the failsafe circuit is working correctly (jumper from T29 to T30 must be installed).

16. Turn on the signal generator and move signal generator frequency from below Rated to above Rated frequency, which is similar to an increase in engine speed. The actuator voltage should now decrease toward zero. Move the frequency back below the Rated speed. Actuator voltage will now increase.

17. Close the Minimum Fuel switch between T22 and T23. Actuator voltage should drop to 0 V.

Procedure T

2301 Operating Conditions

Mounting Locations

The 2301 Control is designed to operate within a temperature range of -40 to 71° C (-40 to 160° F). The unit may be mounted in any position if the required ventilation is available for cooling, and it is not in a high vibration area.

Do not mount the control near very high temperature areas or near auxiliary electrical equipment. It must not be mounted on the engine, and should have space available for servicing and repair.

Electrical Connections

Wiring diagrams for Service Procedures A and B shows all external wiring connections of a typical control installation. Be sure to follow all shielding requirements. The information that follows gives additional specific wiring instructions.

Shielded Wiring

All shielded cable must be twisted conductor pairs. Do not try to tin the braided shield. All input control wires should be shielded. (See wiring drawing for shielding requirements.) This prevents any effects from outside signals (EMR) caused by other electronic equipment near the cable. Connect one point of the shield to the system ground (chassis) at the control end only. The end away from the control should be left open. Do not run shielded wires in the same conduit with cables that carry high current.

Potential Transformer (PT) Connections (Parallel Unit Only)

Connect the potential transformer (PT) secondary leads to the following terminals: Phase A to T1, Phase B to T2, Phase C to T3. The PT secondary line-to-line voltage must be 90 to 240 Vrms. Make reference to the typical wiring diagram in Service Procedure B.

Procedure U

Incompatibility of Multiple Load Sharing Control Units

When multiple (two or more) generator sets are run in parallel to produce a combined output, each engine must be controlled the same for the correct total output. If the engines being paralleled drop off the line due to excessive reverse power as soon as the breakers are closed, then governor incompatibility (not able to function together correctly) could be the cause.

Measure the voltage at each of the 2301 Controls between terminals T13 (negative supply voltage) and terminal T11 (paralleling line common). These voltages must be within 2 volts of each other.

If one of the control units does not measure within two volts of the others, this control may be the cause of the paralleling problem. Use a solid connection (no contacts) to connect terminal T11 of all 2301 Controls together.

When this system is used, the procedure that follows is necessary to avoid system instability. If it becomes necessary to remove power from any one of the controls during operation of the other engine(s), both the positive (+) and the negative (-) connections must be disconnected from that control at the same time. A double pole switch is required for this operation. See the Wiring Diagram that follows for correct installation of the switches.

NOTE: For terminal T25 connection shown, see Service Procedure F for correct controls.

PARALLELING LINE COMMON HARDWIRED

Procedure V

Overvoltage Protection For Woodward 2301 Governors

The 4W5391 Preregulator is a device to limit supply voltage to 36 ± 2 volts. The preregulator attaches to the 2301 Governor and may be received prewired to the 2301 or ordered separately. The 4W5391 Preregulator comes with two extra fuses, all necessary wiring installed, and all necessary instructions. The Preregulator mounts on the 2301 back plate studs.

The 4W5391 Preregulator should be used on any 2301 Governor installation where overvoltage or reverse polarity voltage can occur. Four of the main causes of 2301 Governor Control failures are:

1. If the battery is disconnected during operation, the engine-driven alternator or battery charger will produce damaging positive voltage spikes of up to 150 volts.

2. With 32-volt Nicad battery systems, the charging voltage has frequently been found to be over 40 volts. The preregulator will reduce charging rates of up to 70 volts to a safe level of 38 volts.

3. Reverse voltage damage caused by incorrect supply voltage connections at installation. This is the main cause of failures on start-up.

4. Incorrect wiring at installation may result in actuator lead shorts. Lead wear or damage during use may also cause shorts. The optional preregulator is fused to prevent current surges from causing damage.

Preregulator Installation Procedure

INSTALLING PREREGULATOR
1. 4W5391 Preregulator Box Assembly.

1. Remove two of the nuts from the back plate studs at the top of the panel. Put the 4W5391 Preregulator Box Assembly (1) in position between the studs and install the nuts back on the studs.

REMOVING POWER SUPPLY LEADS
2. Power supply leads.

2. Remove power supply leads (2) from panel terminals T12 (+) and T13 (-) [on Standby unit, T1 (-) and T2 (+)].

INSTALLING POWER SUPPLY LEADS TO PREREGULATOR
2. Power supply leads.

3. Check the other ends of power supply leads (2). If these leads are not connected as close as possible to the battery (for example, if they are connected to the starter), remove them. If necessary, install new leads of the same gauge wire (make sure they are connected as close as possible to battery). Connect power supply leads (2) to correct BATTERY (+) and (-) terminals on preregulator.

WIRING PREREGULATOR TO PANEL
3. (+) lead. 4. (-) lead.

4. Load Sharing Control: Connect lead (3) from preregulator (+) CONTROL terminal to terminal T12 (+) on the control panel. Connect lead (4) from preregulator (-) CONTROL terminal to terminal T13 (-) on the control panel.

Standby Control: Connect lead (3) from preregulator (+) CONTROL terminal to terminal T2 (+) on the control panel. Connect lead (4) from preregulator (-) CONTROL terminal to terminal T1 (-) on the control panel.