6
Bench Check Procedures for testing the VR758
Voltage Regulator.
1 2 3 4 5 6
120vac
fused at
5 amps
120v light
bulb, 25w or
higher
To test the regulator for flat
response regulation, remove the
selection jumper as shown in the
installation instructions.
1.
Connect up the test unit as shown above.
2.
Turn voltage and stability adjustments fully counter clockwise (left 25 turns).
3.
Apply 120vac to the voltage regulator. The test light bulb should be off and the green
system indicator light should be on.
4.
Turn the voltage adjustment clockwise until the test light turns fully on. The bulb will
only glow at1/2 brilliance with a 120vac input to the voltage regulator. Turn the voltage
adjustment counter clockwise until the light turns off.
5.
Turn the stability adjustment clockwise until the test light turns on, then turn the
stability control counter clockwise until the test light turns off.
6.
Momentarily short out the terminals 5 and 6. The test light bulb should glow. Remove
the short and the bulb should not glow.
7.
Turn the voltage and stability adjustments fully counter clockwise (left 25 turns or
more) and remove the voltage from the regulator.
8.
If the regulator performed all of the tests listed above, the regulator is good, if it failed
any of the tests, it is defective.
Test Light
