The Under Voltage trip stops you putting a generator that is not generating full voltage onto the board.
Checking of the trips:
I would always check the makers Instruction Manual for the specific breaker before trying to do anything.
As this is a procedure that is usually carried out for the Classification Society Special Survey of Electrical Equipment, and will usually be carried out by a specialist electrical contractor, often the licensed service agent for the Breaker Manufacturer. It would usually be carried out as part of the 5 yearly Special Survey during a drydock when the vessel would be on shore power.
No testing would normally be carried out with the Alternator running yet alone on load. The Breaker would have to be electrically isolated from the Generators and the Main Bus Bars to test it. So it would usually be "Racked out" of the Board.
Old Breakers have simple electo mechanical trips for overload and undervoltage, and can only be tested by current injection. This involves connected the low voltage, high current windings of a transformer across the breaker, the output current, delivered at only a few Volts, is adjusted until the breaker trips.
More Modern breakers have sophisticated Electronic devices to trip the breaker in addition to the electro mechanical system and sometimes these can be tested by adjusting the set points for undervoltage and over current to the actual operating conditions and thus causing the breaker to trip. However, these devices are often not accepted by Class or Statutory Surveyors who require the Electro Mechanical system to be working.
Testing the trips by changing the set points is only acceptable if you can prove that the calibration of the sensors is correct at the normal trip point.
Checking of the trips:
I would always check the makers Instruction Manual for the specific breaker before trying to do anything.
As this is a procedure that is usually carried out for the Classification Society Special Survey of Electrical Equipment, and will usually be carried out by a specialist electrical contractor, often the licensed service agent for the Breaker Manufacturer. It would usually be carried out as part of the 5 yearly Special Survey during a drydock when the vessel would be on shore power.
No testing would normally be carried out with the Alternator running yet alone on load. The Breaker would have to be electrically isolated from the Generators and the Main Bus Bars to test it. So it would usually be "Racked out" of the Board.
Old Breakers have simple electo mechanical trips for overload and undervoltage, and can only be tested by current injection. This involves connected the low voltage, high current windings of a transformer across the breaker, the output current, delivered at only a few Volts, is adjusted until the breaker trips.
More Modern breakers have sophisticated Electronic devices to trip the breaker in addition to the electro mechanical system and sometimes these can be tested by adjusting the set points for undervoltage and over current to the actual operating conditions and thus causing the breaker to trip. However, these devices are often not accepted by Class or Statutory Surveyors who require the Electro Mechanical system to be working.
Testing the trips by changing the set points is only acceptable if you can prove that the calibration of the sensors is correct at the normal trip point.
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