Guardian Technologies 4758 Test 71 Check N1 and N2 Voltage, Test 73 Test SET Exercise Switch

SECTION 4.4

DIAGNOSTIC TESTS

PART 4

DC CONTROL

RESULTS:

1.If CONTINUITY is not measured in Step 5, repair or replace Wire 66A between Connector C2 and Connector J1 at the circuit board.

2.If CONTINUITY was not measured in Step 6, repair or replace Wire 55 between Connector C2 and the ground terminal.

3.If CONTINUITY was measured in both Step 5 and Step 6, go to Test 7.

4.If AC voltage is not correct in Step 9, proceed to Test 7. If frequency is not correct adjust no load frequency and re-test.

TEST 71 - CHECK N1 AND N2 VOLTAGE

DISCUSSION:

Loss of utility source voltage to the generator will initiate a startup and transfer by the generator. Testing at the control panel terminal strip will divide the system in two, thereby reducing troubleshooting time.

PROCEDURE:

Note: Verify that Utility Source Voltage is present.

1.Set the AUTO-OFF-MANUAL switch to OFF.

2.Set a VOM to measure AC voltage.

3.Connect one test lead to Wire N1 at the terminal strip in the generator control panel. Connect the other test lead to Wire N2. Utility line-to-line voltage should be measured.

RESULTS:

1.If voltage was measured in Step 3, go to Test 65.

2.If voltage was not measured in Step 3, go to Test 28.

4.Connect one meter test lead to Pin Location J1-14 (Wire 225). Connect the other test lead to Pin Location J1-15 (Wire 224). Approximately 14-16 VAC should be measured.

RESULTS:

1.If voltage was measured in Step 4, replace the circuit board.

2.If voltage was NOT measured in Step 4, repair or replace Wire 224 and/or No. Wire 225 between Transformer (TX) and Circuit Board Connector J1.

TEST 73 - TEST SET EXERCISE SWITCH

DISCUSSION:

If the Set Exercise Switch (SW2) fails closed, the unit will start when in AUTO. In normal operation the Normally Open contacts close when the switch is depressed. This will ground Wire 351 and reset the exercise time.

PROCEDURE:

1.Set a VOM to measure resistance.

2.Disconnect Wire 351 and Wire 0 from the Set Exercise Switch (SW2).

3.Connect one meter test lead to one terminal of SW2. Connect the other test lead to the remaining terminal of SW2. The meter should read INFINITY.

4.With the meter test leads connected to SW2, depress and hold the switch activated. The meter should read

CONTINUITY.

TEST 72 - CHECK UTILITY SENSING VOLTAGE

AT THE CIRCUIT BOARD

DISCUSSION:

If the generator starts and transfer to STANDBY occurs in the automatic mode, even though an acceptable UTILITY source voltage is available from the Transformer (TX), the next step is to determine if that sensing voltage is reaching the circuit board.

PROCEDURE:

1.Set the AUTO-OFF-MANUAL switch to OFF.

2.Disconnect Connector J1 from the circuit board.

3.Set a VOM to measure AC voltage.

Figure 35. The Set Exercise Switch

5.Disconnect the five pin connector (J2) from the circuit board.

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