Generac Power Systems 17 kW LP Test 35 Check N1 and N2 Wiring, Test 36 Check N1 and N2 Voltage

Transfer switch

Part 3

Section 3.4

Diagnostic tests

PROCEDURE:

1.On the generator panel, set the AUTO-OFF-MANUAL switch to OFF.

2.Turn off the utility power supply to the transfer switch, using whatever means provided.

3.Remove fuses F1 and F2 from the fuse holder (see Figure 8).

4.Inspect and test fuses for blown condition. With a VOM set to measure resistance, CONTINUITY should be measured across the fuse.

N1A F2 N2A BLACK

F3

F1

N1 N2 T1

Figure 8. Fuse Holder and Fuses

RESULTS:

1. Replace blown fuse(s) as needed.

Test 35 – Check N1 and N2 Wiring

DISCUSSION:

A shorted Wire N1 or N2 to ground can cause fuse F1 or F2 to blow.

PROCEDURE:

1.On the generator panel, set the AUTO-OFF-MANUAL switch to OFF.

2.Turn off the utility power supply to the transfer switch, using whatever means provided.

3.Remove fuses F1, F2, and F3 from the fuse holder (see Figure 7).

4.Remove the generator control panel cover. Disconnect the N1/N2 connector that supplies the printed circuit board located in the control panel (see Figure 6).

5.Set VOM to measure resistance.

6.Connect the positive meter test lead to Wire N1 at the terminal block in the control panel.

a.Connect the negative meter lead to the ground lug. INFINITY should be measured.

b.Connect the negative meter lead to Wire 23 at the terminal strip. INFINITY should be measured.

c.Connect the negative meter lead to Wire 15B at the terminal strip. INFINITY should be measured.

d.Connect the negative meter lead to Wire 0 at the terminal strip. INFINITY should be measured.

e.Connect the negative meter lead to Wire N2 at the terminal block. INFINITY should be measured.

f.Connect the negative meter lead to the neutral connection. INFINITY should be measured.

7.Connect the positive meter test lead to Wire N2 at the terminal block in the control panel.

a.Connect the negative meter lead to the ground lug. INFINITY should be measured.

b.Connect the negative meter lead to Wire 23 at the terminal strip. INFINITY should be measured.

c.Connect the negative meter lead to Wire 15B at the terminal strip. INFINITY should be measured.

d.Connect the negative meter lead to Wire 0 at the terminal strip. INFINITY should be measured.

e.Connect the negative meter lead to the neutral connection. INFINITY should be measured.

RESULTS:

If a short is indicated in Step 6 or Step 7, repair wiring and re-test.

Test 36 – Check N1 and N2 Voltage

Discussion:

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

Procedure:

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

2.Set a VOM to measure AC voltage.

3.See Figure 9. Connect one test lead to Wire N1 at the terminal block in the generator control panel. Connect the other test lead to Wire N2. Utility line-to-line voltage should be measured.

Results:

Refer to Flow Chart

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