Generac Power Systems 7 kW NG, 10 kW LP, 13 kW NG, 9 kW NG Output, Test 32 Utility Control Circuit

Section 3.4

Diagnostic tests

Part 3

Transfer switch

(2)Press the right arrow key until “Debug” is flashing.

(3)Press “Enter”.

(4)Press the right arrow key until “Outputs” is flashing.

(5)Press “Enter”.

(6)Digital Output 8 is Wire 23 output from the board. Refer to Figure 5.

(7)If Output 8 shows a “1” then the control board is grounding Wire 23. Replace the printed circuit board.

c.If 0 VDC is measured, the Wire 23 circuit is good. Refer to flow chart.

DEBUG

OUTPUTS

OUTPUTS 1 - 8:

1 0 1 1 0 0 0 1

OUTPUT 8

Figure 5. The Home Page, Debug and Output Screens

6.Locate the terminal strip in the generator control panel. Disconnect Wire 23 coming in from the transfer switch (customer connection, side-see Figure 6).

7.Connect the positive (+) meter test lead to Wire 15B at the terminal strip in the generator. Connect the nega- tive (-) meter test lead to Wire 23 just removed from the terminal strip.

a.If 0 VDC is measured, proceed to Step 8.

b.If 12 VDC is measured, a short to ground exists on Wire 23 between the generator and transfer switch. Repair or replace Wire 23 as needed between generator control panel and transfer switch relay (TR1).

8.Locate the terminal strip in the generator control panel. Disconnect Wire 23 coming in from the transfer switch (customer connection, side - see Figure 6).

CUSTOMER SIDE

N1/N2
CONTROL BOARD
CONNECTION
			5B1 23
		0
	N1 N2

GENERATOR

TERMINAL STRIP

Figure 6. Transfer Relay Test Points

9.Disconnect the J2 connector from the printed circuit board.

10.Set VOM to measure resistance.

11.Connect one meter test lead to Wire 23 connected at generator terminal strip. See Figure 6. Connect the other meter test lead to control panel ground.

a. If INFINITY or open is measured, replace the printed circuit board

b. If continuity measured, Wire 23 is shorted to ground. Repair or replace Wire 23 between the J2 connector and the generator terminal strip.

TEST 32 – Utility Control Circuit

DISCUSSION:

Printed circuit board action controls grounding Wire 23 to initiate a transfer to standby. When Wire 23 is grounded the transfer relay (TR1) is energized. To initiate a transfer back to utility the TR1 relay must be de-energized. If Wire 23 is grounded, TR1 will always be energized.

PROCEDURE/ RESULTS:

Refer to Figure 7.

1.Turn off utility supply voltage to the transfer switch.

2.Set VOM to measure AC voltage.

3.Set the generator AUTO-OFF-MANUAL switch in the OFF position. Remove Wire 15B from the transfer switch terminal strip.

4.Verify the transfer switch is down in the standby position.

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