Procedure to Isolate the Synchronizing Lights Module on 3516C Power Module {7451} Caterpillar

Engine:

3516C (S/N: NAM1-UP)

3516C (S/N: KEN1-UP)

Introduction

This special instruction contains a procedure in order to rework the wiring harness. The procedure will isolate the Synchronizing Light Module (SLM). With the current design, the SLM is wired directly to the generator and the bus of the breaker for the generator. The direct wiring may allow voltage to travel from the generator to the bus when the breaker for the generator is open.

These changes are effective with the following machines.

• 3516C (S/N: NAM1-UP)

• 3516C (S/N: KEN1-UP)

3516C XQ2000 controls for manual paralleling

Illustration 1	g02022307
Controls for the XQ2000 generator for manual paralleling

3516C XQ2000 controls for automatic paralleling

Illustration 2	g02022313
Controls for the XQ2000 generator for auto paralleling

Important Safety Information

Work safely. Most accidents that involve product operation, maintenance, and repair are caused by failure to observe basic safety rules or precautions. An accident can often be avoided by recognizing potentially hazardous situations before an accident occurs.

A person must be alert to potential hazards. This person should also have the necessary training, skills, and tools in order to perform these functions properly.

Safety precautions and warnings are provided in this instruction and on the product. If these hazard warnings are not heeded, bodily injury or death could occur to you or to other persons. Caterpillar cannot anticipate every possible circumstance that might involve a potential hazard.

Therefore, the warnings in this publication and the warnings that are on the product are not all inclusive. If a tool, a procedure, a work method, or operating technique that is not recommended by Caterpillar is used, ensure that it is safe for you and for other people to use.

Ensure that the product will not be damaged or the product will be made unsafe by the operation, lubrication, maintenance, or the repair procedures that are used.

The following will guide the user in the procedure to modify the wiring in the XQ2000 Generator in order to prevent leakage of generator voltage.

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Accidental engine starting can cause injury or death to personnel working on the equipment. To avoid accidental engine starting, disconnect the battery cable from the negative (−) battery terminal. Completely tape all metal surfaces of the disconnected battery cable end in order to prevent contact with other metal surfaces which could activate the engine electrical system. Place a Do Not Operate tag at the Start/Stop switch location to inform personnel that the equipment is being worked on.

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Only persons with training in electrical installations must carry connections to the generator. The generator must be wired correctly. A fire or electrocution could result from wiring that is incorrect. The generator is capable of generating high voltages. Ensure that the generator is not on while the connections are being made. Follow these two steps in order to prevent accidental starting: Isolate the DC breaker. Disconnect the DC supply battery.

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High voltage may be present. The power source must be disconnected before working on the equipment. Failure to disconnect the power source could result in injury or death. Verify that the equipment is not energized before performing any maintenance. This work must be performed by trained personnel with correct tools and procedures.

Procedure for XQ2000 With Manual Paralleling Controls Only

The XQ2000 with manual paralleling includes a Synchronizing Light Module (SLM). The SLM is wired directly to the generator and the BUS of the breaker for the generator. Refer to Illustration 4. The direct wiring could allow voltage from the generator to flow to the bus while the breaker for the generator was open. The condition creates a potential shock hazard.

Illustration 3	g02033056
Synchronizing Light Module (SLM) (1) Synchronizing Switch (SS)

A potential shock hazard was identified in a factory test. The test unit was started and the breaker for the generator remained open. The Synchronizing Switch (SS) (1) on the SLM was placed in the ON position. The test unit was tested in a stand-alone application (dead bus).

Using a digital voltmeter at the bus bar will verify that the generator voltage is approximately 480 VAC on phase L1 and L3. Refer to Illustration 4. Evidence indicated that the Synchronizing Check Relay (6) contributed to a flow of voltage of 5 VAC. The 5 VAC was increased to 20 VAC at the BUS when a voltage check was taken at the power transformers.

In order to make the repair, isolate the SLM when no other unit is energizing the bus. Refer to Illustration 5. The revised circuit was verified in a factory test under the same operating conditions. A reading with a meter was taken on the bus in order to verify voltage on the new circuit. The reading on the meter was less that 1 VAC. The unit in the test was closed to a dead bus condition repeatedly. The unit was also paralleled to another unit in order to verify proper operation.

Instructions For Isolating The Synchronizing Light Module (SLM)

Removing The Existing Wiring

Illustration 4	g02032996
Manual paralleling with original wiring to SLM

1. Remove wiring from SLM that attach to the following fuses: F4 wiring (5), F6 wiring (3), F10 wiring (3) and F12 wiring (2) .

   Refer to Illustration 4.

2. Remove all other wiring from SLM.

   Note: Do not remove wire (6) from connection 1 of the Synchronizing Switch (SS) of the SLM that is connected to 1 at SL1 of the SLM.

   Refer to Illustration 4.

Installing The New Wiring

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Illustration 5	g02033000
Manual Paralleling with revised wiring (7) Synchronizing Check Relay

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Illustration 6	g02033055
(7) Synchronizing Check Relay (8) Dead Bus Relay (DBR)

Note: Use Gray-16 AWG wire that is rated at 90° C (195° F) at 600 V for the following steps.

1. Install wire from connection 3 of the Synchronizing Check Relay to connection 24 of the Dead Bus Relay DBR (8) .

   Refer to Illustration 5.

2. Install wire from connection 21 of the DBR (8) to connection 4 at SS of the SLM.

   Refer to Illustration 5.

3. Install wire from connection B at SLR2 of the SLM to connection 2 at SL2 of the SLM.

   Refer to Illustration 5.

4. Install wire from connection 2 at SL1 of the SLM to connection 1 at SL2 of the SLM.

   Refer to Illustration 5.

5. Install wire from connection 1 of the Synchronizing Check Relay (6) to connection E at SLR2 of the SLM.

   Refer to Illustration 5.

Note: SLR1 and SLR2 are mounted on the back of SLM.

Procedure for Adding an Additional Dead Bus Relay for Manual Paralleling Controls and Auto Paralleling Controls

Illustration 7	g02034394
Manual Paralleling with revised wiring (21) Dead Bus Relay 2 (DBR2) (22) Synchronizing Check Relay

Illustration 8	g02034395
Auto Paralleling with revised wiring (21) Dead Bus Relay 2 (DBR2) (22) Synchronizing Check Relay

The following procedure improves the isolation from the BUS. An additional Dead Bus Relay will be added to the circuit. Refer to Illustrations 7 and Illustration 8. The Dead Bus Relay 2 DBR2 senses L2 and L3. The DBR senses L1 and L2. The DBR2 can only be energized by another source that is powering the BUS. The single Dead Bus Relay could be energized by flow of voltage from the generator in a situation when the Synchronizing Check Relay (22) has internal failure. Thus, the normally open contact from DBR2 isolates the Synchronizing Check Relay (22) from the BUS by preventing voltage to flow even if the Synchronizing Check Relay (22) has failed internally.

Illustration 9	g02034400
(25) PT1 (26) PT2 (27) PT3 (28) PT4 (29) Mounting location for the DBR2 relay (30) Mounting location for the DBR2 base for the relay (31) F16 Fuse (top location) (32) F15 Fuse (second locator from top)

Install one 2-pole relay (29) and one 2-pole base (30) at top of the DIN rail in lower compartment. Refer to Illustration 9.

• (29) 340-1154 Relay at 120 V.

• (30) 179-8828 Base

Install Gray-16 AWG wire that is rated at 90° C (195° F) at 600 V.

1. Remove the wire from the harness that is attached to terminal 3 on the Synchronizing Check Relay (22). Insulate the wire and place the wire in a stowed position.

2. Install wire from fuse F-16 (RH screw terminal) to A1 at DBR2.

3. Install wire at connection X1 on PT4 to connection A2 at DBR2.

4. Install wire from fuse F15 (RH screw Terminal) to connection 11at DBR2.

5. Install wire from 14 at DBR2 to connection 3 at Synchronizing Check Relay (22). Pin connections on production equipment are identified.

Verification Test

Perform the following tests on the unit.

1. Lock out the breaker for the generator in the open position.

2. Start the engine.

3. Verify the following VAC measurements.

   1. The voltage for the Synchronizing Check Relay (22) at terminal 1 and at terminal 2 should read approximately 120 VAC.

   2. The voltage for the Synchronizing Check Relay (22) at terminal 3 and at terminal 4 should read approximately 60 to 75 VAC.

   3. The customer connection at bus bar L1 and L2 should read approximately 0 VAC.

   4. The customer connection at bus bar L2 and L3 should read approximately 0 VAC.

   5. The customer connection at bus bar L1 and L3 should read approximately 0 VAC.

4. Shut down the engine.

5. Lock out the generator. Lock out the breaker for the generator in the open position.

Perform a parallel test with another unit. The test does not require a load.

Note: The unit that is used for paralleling must be the lead unit. The jumper wire must be installed to the lead unit.

Note: When there is more than one power module, the jumper wire will designate the unit that will be the lead power module.

1. Energize the bus from the unit for paralleling.

2. Start the engine by pressing the "RUN" button. Do not parallel the unit to the bus.

3. By using a multimeter, verify that the normally open contact on the Synchronizing Check Relay (22) closes as the generator becomes synchronized with the bus. Observe the synchroscope.

4. Perform manual paralleling to the bus. Then open the breaker for the generator. Perform the procedure twice.

5. Shut down the unit that was used for paralleling.

6. Attempt to close the breaker for the generator manually to verify that the breaker will not close to a dead bus.

7. Shut down the engine.