Generac Power Systems 941-2, 940-2 Testing The Battery Charge Circuit, Section COMPONENTS TESTING

Section 1.5

COMPONENTS TESTING

7.Connect one test lead to Stator lead PS1, the other to Stator lead 77. The VOM should read "infinity".

8.Connect one VOM test lead to Stator lead TIM1, the other test lead to Stator lead 77. "Infinity" should be Indicated.

TESTING THE BATTERY CHARGE CIRCUIT

GENERAL:

The Stator is equipped with dual battery charge wind- ings. These windings deliver an AC output to a Battery Charge Rectifier (BCR) which rectifies it (changes it to direct current or DC). The direct current is delivered to the unit battery, to maintain the battery in a charged state while the unit is running.

Figure 3. Battery Charge Windings and Rectifier

SYMPTOMS OF CIRCUIT FAILURE:

It is difficult to determine if the battery charge circuit is operating without testing for correct voltage. If you suspect the battery charge circuit Is defective, the fol- lowing symptoms will usually point to a cause of the problem. See Figure 4.

1.If no AC voltage can be measured across Stator connections at the Battery Charge Rectifier (BCR), an open circuit condition probably exists in Wire 66 (Brown), or Wire 77 (Brown).

2.If AC voltage (s available to the Wire 66 and 77 terminals at the battery Charge Rectifier, but no voltage or a low voltage is mea- sured between the BCR's Wire 55 terminal and ground, the Battery Charge Rectifier (BCR) is defective.

Figure 4. Battery Charge Circuit

TESTING THE BATTERY CHARGE CIRCUIT: Test the Battery Charge winding as follows:

1.Disconnect Wire 77 at the Battery Charge Rectifier (BCR).

2.Disconnect Stator output Wire 66 at the Battery Charge Rectifier (BCR).

3.Disconnect Wire 55.

4.Set a VOM to its "Rx1 " scale and zero the meter.

5.Connect the VOM test leads across Wires 77 and 55, then across Wires 66 and 55. Note the resistance reading in both cases. Replace Stator Assembly, if defective.

BATTERY CHARGE WINDING RESISTANCE ACROSS WIRES 66 TO 55 = 0.095-0.108 Ohm ACROSS WIRES 77 TO 55 = 0.095-0.108 Ohm

6.Use a VOM to measure AC voltage at the Wires 66 and 77 ter- minals of the Battery Charge Rectifier, with the unit running. If no AC voltage is measured, an open circuit exists in the wire 66 or 77 circuit.

7.With engine running, use a VOM to check for DC voltage between the Battery Charge Rectifiers Wire 55 and frame ground. If AC voltage was present in step 6, but DC voltage is NOT present in this step, the Battery Charge Rectifier (BCR) is defective.

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