9
Service and Repair Manual
Model 840S
WARNING
LETHAL VOLTAGES PRESENT!!
IMPORTANT
On completion of the assembly, the unit must be flash tested at 4000 volts.
Flash Test
1.
With the breaker completely assembled and with the switch "ON", apply 2000 volts initially and increase rapidly to 4000 volts between the
main casting and one of the pins of the plug on the power supply cord. Apply test to both live and neutral pins.
2.
The full voltage of 4000 volts should be maintained without breakdown or flashover for a few seconds.
3.
If the armature has been tested, remove the carbon brushes before carrying out the test, (thus avoiding overstressing the armature
insulation system).
4.
The test voltage must be applied between the main casting and each live pin of the plug in succession.
Running Test
1.
Ensure the unit is switched "ON" before testing. Operate the unit for approx. 10 minutes at half voltage for initial 'bedding in' of the carbon
brushes followed by full operational voltage. Compare readings with Performance Data.
With the aid of the Fault Finding chart (below) the source of any malfunction may be quickly identified and repaired.
FAULT FINDING
