Guardian Technologies 4389, 4456, 4390, 4760, 4759, 4758 Test 65 Check Transformer TX Voltage Output

DC CONTROL

PART 4

SECTION 4.4

DIAGNOSTIC TESTS

TEST 65 - CHECK TRANSFORMER (TX)

VOLTAGE OUTPUT

DISCUSSION:

The Transformer (TX) is a STEP DOWN type and has two functions. It supplies approximately 16 VAC to the control panel circuit board for utility sensing. It also supplies approximately 16 VAC to the battery charger for trickle charging. A defective transformer will:

a. not supply AC to the battery charger, and

b. not supply sensing voltage to the circuit board.

RESULTS:

1.If line-to-line voltage was NOT measured in Step 2, go to Problem 7, Page 3.3-2.

2.If correct voltage was measured in Step 2, and no voltage was measured in Step 3, replace the Transformer.

3.If correct voltage was measured in Step 2, and no voltage was measured in Step 4, replace the Transformer.

4.If voltage output was correct for Step 3 and for Step 4, refer back to the Flow Chart (Page 4.3-5).

Figure 32. Transformer (TX)

PROCEDURE:

1.Set a VOM to measure AC voltage.

2.Connect one meter test lead to the Transformer (TX) Terminal 5, Wire N1. Connect the other meter test lead to the Transformer (TX) Terminal 1, Wire N2. Utility line- to-line voltage (240 VAC) should be measured.

3.Connect one meter test lead to the Transformer (TX) Terminal 6 with Wire 225A removed. Connect the other meter test lead to the Transformer (TX) Terminal 7 with Wire 224A removed. This output supplies power to the battery charger. The VOM should measure approximately 16 VAC.

4.Connect one meter test lead to the Transformer (TX) Terminal 9 with Wire 224 removed. Connect the other meter test lead to the Transformer (TX) Terminal 10 with Wire 224 removed. This AC output is used as utility sensing, and is supplied to the circuit board. The VOM should measure approximately 16 VAC.

TEST 66 - CHECK AC VOLTAGE AT BATTERY

CHARGER

DISCUSSION:

The battery charger needs to be supplied with approximately 16 VAC. When the generator is not running and utility source power is available, the battery charger still receives voltage from the Transformer (TX). When the generator is running, voltage is supplied to the battery charger from the battery charge winding.

PROCEDURE:

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

Note: Utility source voltage MUST be available to the generator.

2.Set a VOM to measure AC voltage.

3.Disconnect the two pin connector (Wire 224B and Wire 225B) at the battery charger.

4.Connect one meter test lead to Wire 224B at the two pin connector. Connect the other test lead to Wire 225B at the two pin connector. Approximately 16 VAC should be measured.

5.Verify that the battery charge relay (BCR) is wired correctly (Figure 33).

6.Connect one meter test lead to Terminal 1, Wire 224A on the BCR. Connect the other test lead to Terminal 3, Wire 225A. Approximately 16 VAC should be measured.

RESULTS:

1.If voltage was NOT measured in Step 6, but was measured in Test 65, repair or replace Wire 224A and Wire 225B between the transformer (TX) and the battery charge relay (BCR).

2.If voltage was not measured in Step 4, go to Test 67.

Page 4.4-19