Usage:
Chapter 1. General Information
Description
The 9905/9907 series of the Woodward 2301A controls load sharing and speed of generators driven by diesel or gasoline engines, or steam or gas turbines. These power sources are referred to as "prime movers" throughout this manual.
The control is housed in a sheet-metal chassis and consists of a single printed circuit board. All potentiometers are accessible from the front of the chassis.
The 2301A provides control in either isochronous or droop mode.
The isochronous mode is used for constant prime mover speed with:
- * Single-prime-mover operation;
- * Two or more prime movers controlled by Woodward load sharing control systems on an isolated bus;
- * Base loading against an infinite bus with the load controlled by an Automatic Power Transfer and Load (APTL) Control, an Import/Export Control, a Generator Loading Control, a Process Control, or another load-controlling accessory.
- * Two or more prime movers controlled by Woodward load sharing control systems on an isolated bus;
The droop mode is used for speed control as a function of load with:
- * Single-prime-mover operation on an infinite bus or
- * Parallel operation of two or more prime movers.
The following is an example of the typical hardware needed for the 2301A system controlling a single prime-mover and generator:
- * A 2301A electronic control
- * An external 20 to 40 Vdc power source for low-voltage models; 90 to 150 Vdc or 88 to 132 Vac for high-voltage models
- * A proportional actuator to position the fuel-metering device, and
- * Current and potential transformers for measuring the load carried by the generator.
- * An external 20 to 40 Vdc power source for low-voltage models; 90 to 150 Vdc or 88 to 132 Vac for high-voltage models
Applications
The 2301A 9905/9907 series electronic controls have switch-selectable speed ranges. Any of these control models can be set to operate within one of the following rated speed ranges:
- * 500 to 1500 Hz
- * 1000 to 3000 Hz
- * 2000 to 6000 Hz
- * 4000 to 12000 Hz
- * 1000 to 3000 Hz
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WARNING-OVERSPEED The speed range is factory set for 2000 to 6000 Hz. Refer to the inside cover to change speed range and prevent possible overspeed. Using the wrong speed range could cause an overspeed with resulting damage to equipment and/or personal injury or death. |
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CAUTION-DO NOT TURN POTS BEYOND THEIR STOPS The Rated Speed potentiometer is the only multi-turn pots in this control. All other pots are single-turn. Take care not to turn these pots beyond their stops. |
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These controls are available for forward- or reverse-acting applications, and for use with either single or tandem actuators. Models for three different actuator current ranges are available, as well as high-voltage model (90 to 150 Vdc or 88 to 132 Vac, 45 to 440 Hz), and a low-voltage model (20 to 40 Vdc). The high voltage model is identified as such on the front, the low voltage model is not.
In reverse-acting systems, the actuator calls for more fuel when the actuator voltage decreases. Complete loss of voltage to the actuator will drive the actuator to full fuel. This allows a backup mechanical ballhead governor to take control rather than shut down the prime mover as would a direct-acting system.
An optional deceleration ramp is also offered. When this option is present, the time to ramp from rated speed to idle speed is approximately 20 seconds. If this option is not present, this happens instantly.
Tables 1-1 and 1-2 show part numbers and features of all 9905/9907 series 2301A load sharing and speed controls.
NOTE: External wiring connections for reverse-acting controls are identical to those for direct-acting controls.
The relationship between prime mover speed and sensor output frequency is expressed in the formula:
References
The following publications contain additional product or installation information on Load Sharing and Speed Controls and related components. They are available on the Woodward website (www.woodward.com/ic).
2301 Load Sharing and Speed Control Models, 9905/9907 Series
Table 1-1. Low-Voltage 2301A Models (20 to 40 Vdc)
Table 1-2. High-Voltage 2301A Models (88-132 Vac or 90-150 Vdc)
NOTE: The 20-40 Vdc input power must be supplied from a power supply/battery charger certified to IEC standard with SELV (Safety Extra Low Voltage) classified output. The installer should properly size wiring and fusing for the input power and PT/CT circuits.
Speed Ranges
On these Woodward 2301A models, any one of the following speed ranges may be selected by a switch:
- * 500 to 1500 Hz
- * 1000 to 3000 Hz
- * 2000 to 6000 Hz
- * 4000 to 12000 Hz
- * 1000 to 3000 Hz
Power Supply Voltage
These Woodward 2301A controls accept either a high-voltage or a low-voltage power source. The low voltage models operate on 20 to 40 Vdc, and the high voltage models operate on either 88 to 132 Vac or 90 to 150 Vdc. Both the low- and high-voltage models require a power capacity of 15 W minimum.
Figure 1-1. 2301A Control Outline Drawing (low voltage version-top, high voltage version-bottom)
Figure 1-2a. Plant Wiring Diagram (low-voltage supply)
Figure 1-2b. Plant Wiring Diagram (high-voltage supply)
Chapter 2. Installation
Unpacking
Before handling the control, read the " Electrostatic Discharge Awareness" precautions on page iii. Be careful when unpacking the electronic control. Check the control for signs of damage such as bent or dented panels, scratches, and loose or broken parts. If any damage is found, immediately notify the shipper.
Power Requirements
The 2301A control requires a voltage source of 18 to 40 Vdc, 90 to 150 Vdc, or 88 to 132 Vac for operating power (15 W). If a battery is used for operating power, an alternator or other battery charging device is necessary to maintain a stable supply voltage.
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CAUTION-BATTERY To prevent damage to the control, make sure that the alternator or other battery-charging device is turned off or disconnected before disconnecting battery from the control. |
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Location Considerations
- * Adequate ventilation for cooling
- * Space for servicing and repair
- * Protection from direct exposure to water or to a condensation-prone environment
- * Protection from high voltage or high current devices, or devices which produce electromagnetic interference
- * Avoidance of vibration
- * Selection of a location that will provide an operating temperature range of -40 to +70°C (-40 to +158°F)
- * The control must NOT be mounted on the engine.
- * Space for servicing and repair
Electrical Connections
External wiring connections and shielding requirements for a typical control installation are shown in the plant wiring diagram (Figure 1-2). These wiring connections and shielding requirements are explained in the balance of this chapter.
Shielded Wiring
All shielded cable must be twisted conductor pairs. Do not attempt to tin (solder) the braided shield. All signal lines should be shielded to prevent picking up stray signals from adjacent equipment. Connect the shields to the control terminals as shown in Figure 2-1 and in the plant wiring diagram (Figure 1-2). Wire exposed beyond the shield should be as short as possible, not exceeding 50 mm (2 inches). The other end of the shields must be left open and insulated from any other conductor. Do not run shielded signal wires with other wires carrying large currents. See Appendix B, EMI Control for Electronic Governing Systems, for more information.
Where shielded cable is required, cut the cable to the desired length and prepare the cable as instructed below and shown in Figure 2-1.
1. Strip outer insulation from BOTH ENDS, exposing the braided or spiral wrapped shield. DO NOT CUT THE SHIELD.
2. Using a sharp, pointed tool, carefully spread the strands of the shield.
3. Pull the inner conductor(s) out of the shield. If shield is the braided type, twist to prevent fraying.
4. Remove 6 mm (1/4 inch) of insulation from the inner conductor(s).
5. Connect wiring and shield as shown.
In installations with severe electromagnetic interference (EMI), shielded wire run in conduit, double shielded wire, or other precautions may be required. Contact Woodward for more information.
Figure 2-1. Preparation and Installation of Shielded Cables
Setting Speed Range
The speed range to be selected is determined by the maximum desired prime mover speed. Calculate the frequency of the speed sensor signal at the maximum prime move speed by multiplying the gear speed in revolutions per minute times the number of teeth on the speed sensing gear and dividing by 60. Select the lowest speed range which contains this maximum speed sensor frequency.
Figure 2-2 shows the four sections of Switch S1 and their corresponding speed ranges. Set the proper section of Switch S1 to the ON position and the other three positions of Switch S1 to the OFF position.
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WARNING-OVERSPEEDThe speed range is factory set for 2000 to 6000 Hz. Refer to the inside cover to change speed range and prevent possible overspeed. Using the wrong speed range could cause an overspeed with resulting damage to equipment and/or personal injury or death. |
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Figure 2-2. Switch S1
Potential Transformer Connections
Connect the potential transformer secondary leads to the following terminals:
- * Phase A to terminal 1
- * Phase B to terminal 2
- * Phase C to terminal 3
- * Phase B to terminal 2
The potential transformer secondary line-to-line voltage must be in the 90 to 240 Vrms range. Refer to the plant wiring diagram (Figure 1-2).
Current Transformer Connections
The standard method of connecting the current transformers is shown in the plant wiring diagram (Figure 1-2). An alternate method is the open delta connection shown in the insert in the plant wiring diagram.
Droop Contact (Isoch-Droop) and Load Sharing Lines
Because the load-sharing-line relay is contained in the control, no relay is required between the control and the load-sharing-line bus. Use shielded cable and connect the load-sharing lines directly to terminals 10 (+) and 11 (-). Connect the shield to terminal 12. When all controls in the system are of the 2301A type, the shields may be connected continuously between controls. When load sharing with different controls, do not connect the shields at the point where connections are made to the load-sharing-line bus.
The droop contact for selecting droop or isochronous operation is wired in series with the circuit-breaker auxiliary contact between terminal 14 and terminal 16 (terminal 0 on high-voltage controls). When both the droop contact and circuit-breaker auxiliary contact are closed, the control is in the isochronous load-sharing mode (Figure 2-3, A). In this mode, the internal load-sharing-line relay is energized, the droop signal is disabled (permitting isochronous load sharing), and the load-matching circuit is connected to the load-sharing lines.
The control is in the droop mode with EITHER the droop contact or the circuit-breaker auxiliary contact is open (Figure 2-3, B). If the droop contact is open, the control remains in the droop mode even when the circuit-breaker auxiliary contact is closed.
Figure 2-3. Droop Contact and Circuit Breaker Auxiliary Contact
NOTE: The control is in the droop mode whenever the circuit-breaker auxiliary contact is open. If a single prime mover is required to run isochronously with an isolated load, turn the DROOP potentiometer fully counterclockwise ( be careful not to overtorque the pot).
Droop operation is required when the generator is paralleled with an infinite bus without a Generator Loading Control, Process Control, Automatic Power Transfer and Load Control, Import/Export Control, or other load controlling accessory, or when paralleled with incompatible governors. (All Woodward electric load-sharing systems are compatible.) When running a single unit on an infinite bus with a Generator Loading Control or Import/Export Control, terminal 14 must be connected to terminal 16 (terminal 0 on high-voltage controls) to connect the Load Matching Circuit to the load-sharing lines. The load-sharing lines must be wired to the Generator Loading Control or Import/Export Control. The circuit-breaker auxiliary contact will then be connected to the Generator Loading Control or Import/Export Control and not to the 2301A Load Sharing and Speed Control.
Power Supply
Run the power leads directly from the power source to the control, connecting the negative lead to terminal 15, and the positive lead to terminal 16. If the power source is a battery, be sure the system includes an alternator or other battery-charging device.
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CAUTION-DO NOT APPLY POWER DO NOT apply power to the control at this time. Applying power before a control is completely connected may damage the control. |
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Minimum Fuel Contact
The minimum-fuel contact is intended as an optional means for a normal shutdown of the prime mover. It is connected in series with terminal 16 (terminal 0 on high-voltage controls) and terminal 17 as shown in the plant wiring diagram (Figure 1-2). Do NOT remove this jumper from terminal 17 unless a minimum fuel contact is installed; the control will not operate without 18 to 40 Vdc applied to terminal 17.
When the contact is closed, the voltage applied to terminal 17 allows the control to move the actuator to any position required for operating conditions.
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WARNING-EMERGENCY STOP Do NOT use the minimum-fuel contact as part of any emergency stop sequence. |
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Failed Speed Signal Override
A contact to override the failed-speed-signal circuit can be installed in series with terminal 18 and the dc power to the control. When the contact is open, the control operates normally, turning the control output off in the event of a loss of speed signal. Closing the contact overrides the failed-speed-signal circuit as may be required for start-up.
Prior to start-up of the prime mover, the speed signal is nonexistent. On prime movers with cranking motors, the cranking speed is usually sufficient to provide a speed signal, so an override contact on terminal 18 is not needed for starting. On some steam turbine systems, the Close to Override Failed Speed Signal contact must be closed to allow the actuator to open and provide steam for starting.
If a failed-speed-signal-override contact is used, it should be of the momentary type to ensure that the failed-speed-sensor shutdown circuit is enabled after start-up.
Idle/Rated Ramp Contact
Connect a single-pole, single-throw switch to terminal 16 (terminal 0 on high-voltage controls) to terminal 19, the Close For Rated (open for idle, close for rated) terminal. Oil pressure is often used to close this contact. When closed, 20 to 40 Vdc is applied to terminal 19, and the prime mover can be operated at a speed higher than idle. When the contact is open, the voltage is removed from terminal 19, and the prime mover's speed immediately decelerates to idle.
Actuator Output
The actuator wires connect to terminals 20 (+) and 21 (-). Use shielded wires with the shield connected to terminal 22. Do not connect the shield to the actuator or any other point. The shield must have continuity the entire distance to the actuator, and must be insulated from all other conducting surfaces. Refer to the manuals listed in Chapter 1, References, table for additional information on actuator installation.
External Speed Trim
A jumper must be connected to terminals 23 and 24 unless an optional remote Speed Trim potentiometer is used. If a Speed Trim potentiometer is used connect it as shown in the plant wiring diagram (Figure 1-2), using shielded wire. Connect the shield to terminal 22. Make sure the shield has continuity the entire distance to the potentiometer, and that the shield is insulated from all other conducting surfaces. A 100 ohm potentiometer will provide ±5% speed adjustment. If less adjustment is desired, potentiometers of smaller values may be used. Potentiometers of the multi-turn type are recommended.
Speed and Phase Matching (SPM) Synchronizer
Connect the SPM Synchronizer (optional equipment) wires to terminals 25 (+) and 26 (-). Use shielded wire, and connect the shield to terminal 27. Make sure the shield has continuity the entire distance to the SPM Synchronizer, but do not connect the shield to the synchronizer. The shield must be insulated from all other conducting surfaces.
Speed Sensor
Connect a speed-sensing device, such as a magnetic pickup, to terminals 28 and 29 using shielded wire. Connect the shield to terminal 27. Making sure the shield has continuity the entire distance to the speed sensor, and that the shield is insulated from all other conducting surfaces.
Installation Check-out Procedure
With the installation completed as described in this chapter, do the following check-out procedure before beginning the start-up adjustments in Chapter 3.
- 1. Visual Inspection
- A. Check the linkage between the actuator and the prime mover for looseness or binding. Refer to the appropriate actuator manual, and to Woodward manual 25070, Electric Governor Installation Guide, for additional information on linkage.
Show/hide table
WARNING-MINIMUM FUEL POSITION
The actuator lever should be near but not at the minimum position when the fuel or steam rack is at the minimum position. If the actuator lever gets to its minimum position before completely shutting off fuel or steam, the control may not be able to shut the turbine down, causing damage to equipment or injury or death.
- B. Check for correct wiring per the plant wiring diagram (Figure 1-2).
- C. Check for broken terminals and loose terminal screws.
- D. Check the speed sensor for visible damage. If the sensor is a magnetic pickup, check the clearance between the gear and the sensor, and adjust if necessary. Clearance should be between 0.25 and 1.00 mm (0.010 and 0.040 inch) at the closest point. Make sure the gear has less than 0.50 mm (0.020 inch) diametric runout. See Woodward manual 82510, Magnetic Pickups & Proximity Switches for Electronic Governors.
- B. Check for correct wiring per the plant wiring diagram (Figure 1-2).
- 2. Check for Grounds
Make sure power is off. Check for grounds by measuring the resistance from terminal 11 to chassis, and from terminal 15 to 11. The resistance should be infinite. If a resistance other than infinite is obtained, remove the connections from each terminal one at a time until the resistance is infinite. Check the line that was removed last to locate the fault.
- A. Check the linkage between the actuator and the prime mover for looseness or binding. Refer to the appropriate actuator manual, and to Woodward manual 25070, Electric Governor Installation Guide, for additional information on linkage.