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Generac — DRAFT

For these Generac models: CTTS STYLE CONTACTOR ASSEMBLY 600-2600 AMP, CTTS Style CONTACTOR Assembly (100-400 Amp), CTTS Style CONTACTOR Assembly (600-2600 Amp), CTTS Style Contactor Assembly, W Style CONTACTOR Assembly, Wn STYLE CONTACTOR ASSEMBLY 600-2600 AMP, Wn Style CONTACTOR Assembly (100-400 Amp), Wn Style CONTACTOR Assembly (600-2600 Amp).

Applies to: Generac Ctts Style Contactor Assembly 600 2600 Amp, Generac Ctts Style Contactor Assembly, Generac W Style Contactor Assembly, Generac Wn Style Contactor Assembly 600 2600 Amp

Before you start

  • IMPORTANT: DISABLE THE GENERATOR

Procedure

  1. 1. Remove the cover on the contactor assembly.
  2. 2. Using a multimeter (set to ohms scale), measure the resistance of the coil as follows and compare the results to the chart provided below.
  3. 3. On the J3 block, measure the resistance between the red wire (blue covering) and the white wire (yellow covering).
  4. 4. Measure resistance from the red wire (blue covering) to the white wire (blue covering)/red wire (yellow covering).
  5. 5. Measure resistance from the white wire (yellow cover­ ing) to the white wire (blue covering)/red wire (yellow covering).
  6. 6. If proper resistance values were not measured in Steps 3 through 5, the closing coil is faulty (Contact service department or replace coil). If proper resistance values
  7. 7. were measured, proceed to .
  8. 7. Remove the screw from the PCB and unplug the harness (located behind the PCB). If the contactor is not in the utility position, manually transfer it to the utility position.
  9. 8. Measure the resistance between the yellow and brown Less than 1 ohm should be measured. If the proper resistance value is NOT measured, replace the LS1 (Part # 0D4516). If proper resistance was measured,
  10. 10. proceed to .
  11. 9. Measure the resistance between the blue and brown INFINITY should be measured. If INFINITY is NOT measured, replace the LS1 (Part # 0D4516). If proper
  12. 10. resistance was measured, proceed to .
  13. 10. With the contactor in utility position, measure the resis­ tance between the orange and gray wires on the female side of the plug. Less than 1 ohm should be measured. If proper resistance is NOT measured, replace the LS2 (Part #0D4516). If proper resistance is measured, pro­
  14. 9. ceed to . Part 1 Troubleshooting Section 1.1 “W” STYLE CONTACTOR ASSEMBLY Page 6 DRAFT Part 1 Troubleshooting Section 1.1 “W” STYLE CONTACTOR ASSEMBLY
  15. 11. With the contactor in utility position, measure the resis­ tance between the green and gray wires on the female side of the plug. INFINITY should be measured. If INF INITY is NOT measured, replace the LS2 (Part # 0D4516). If proper resistance was measured, proceed
  16. 12. to .
  17. 12. If all tests prove favorable results, replace the PCB (Part # 0D7400). SWITCH WILL NOT RETRANSFER TO UTILITY If the GTS/HTS “W” switch will not retransfer to utility power and utility voltage is measured on Wires 126 (A1) and N2 (A2), then proceed as follows: * FROM STARTING. Follow all Safety guide­ lines and insure that the unit is 100% dis­ abled by confirming that it’s in the “OFF” position, the Main Line Circuit Breaker is in the “OPEN” position and that the “NEGATIVE” Battery Cable is properly disconnected. In addition, verify utility power is secured and service entrance disconnect is in the off or open position.
  18. 1. Remove the cover on the contactor assembly.
  19. 2. Using a multimeter (set to ohms scale), measure the resistance of the coil as follows and compare the results to the chart provided below.
  20. 3. Measure resistance between J2-1 and J2-3. Closing coil

Source: manual:Generac GTS Trouble Shooting - 0H3949-A2.pdf. Figures and steps are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.