5. Remove Wire N2A from the utility coil C1.6. Turn on utility power supply to the transfer switch.a. If transfer to utility occurs, Wire 23 is grounded.Proceed to Test 31.b. If transfer to utility does not occur, proceed toStep 7.7. Measure across points A and B. 240 VAC should bemeasured.a. If 240 VAC is not measured, verify utility source.b. If 240 VAC is measured, proceed to Step 8.8. Measure across points C (Wire N2A previously removed)and B. 240 VAC should be measured.a. If 240 VAC is not measured, repair or replaceWire N2A.b. If 240 VAC is measured, proceed to Step 9.9. Measure across points A and D. 240 VAC should bemeasured.a. If 240 VAC is not measured, repair or replaceWire N1A.b. If 240 VAC is measured, proceed to Step 10.10. Measure across points A and E. 240 VAC should bemeasured.a. If 240 VAC is not measured, repair or replaceWire N1A.b. If 240 VAC is measured, proceed to Step 11.11. Measure across points A and F. 240 VAC should bemeasured.a. If 240 VAC is not measured, replace transferrelay.b. If 240 VAC is measured, proceed to Step 12.12. Measure across points A and G. 240 VAC should bemeasured.a. If 240 VAC is not measured, repair or replaceWire 126.b. If 240 VAC is measured, proceed to Step 13.13. Measure across points A and H. 240 VAC should bemeasured.a. If 240 VAC is not measured, verify limit switchSW2 is wired correctly. Proceed to Test 33.b. If 240 VAC is measured, proceed to Step 14.14. Measure across points A and I. 240 VAC should bemeasured.a. If 240 VAC is not measured, repair or replaceWire A.b. If 240 VAC is measured, replace utility coil C1.Coil nominal resistance is 1-2 megohms.teSt 33 – teSt limit SWitch SW2 and SW3DISCUSSION:The limit switches are wired to the normally closedcontacts. When the switches are activated thecontacts open.PROCEDURE:With the generator shut down, the generator maincircuit breaker turned OFF, and with the utility powersupply to the transfer switch turned OFF, test limitswitch SW2/SW3 as follows:1. To prevent interaction, disconnect Wire 126 and Wire Afrom limit switch SW2 terminals.2. Set a VOM to its “R x 1” scale and zero the meter.3. See Figure 1. Connect the VOM meter test leadsacross the two outer terminals from which the wireswere disconnected.4. Manually actuate the main contacts to their Standbyposition. The meter should read CONTINUITY.5. Manually actuate the main contacts to their Utilityposition. The meter should read INFINITY.6. Repeat Steps 4 and 5 several times and verify the VOMreading at each switch position.7. To prevent interaction, disconnect Wire 205 and Wire Bfrom limit switch SW3 terminals.8. See Figure 1. Connect the VOM meter test leadsacross the two outer terminals from which the wireswere disconnected.9. Manually actuate the main contacts to their Standbyposition. The meter should read INFINITY.10.Manually actuate the main contacts to their Utilityposition. The meter should read CONTINUITY.11. Repeat Steps 4 and 5 several times and verify the VOMreading at each switch position.RESULTS:1. If Limit Switch SW2 or SW3 fails the test, remove andreplace the switch or adjust switch until it is actuatedproperly.teSt 34 – check FuSeS F1 and F2DISCUSSION:Fuses F1 and F2 are connected in series with the N1and N2 circuits, respectively. A blown fuse will openthe applicable circuit and will result in (a) generatorstartup and transfer to “Standby”, or (b) failure toretransfer back to the utility source.Page 82Part 3 TRANSFER SWITCHsEctioN 3.4DiaGNostic tEsts0G9266revA.indd 82 10/15/2008 11:27:34 AM
