Electrical Protection

Current Transformers

CT’s are instrument transformers that are used to measure current through a conductor to provide the required data for protection systems.

There are two types of CTs

1.Metering CT are used to measure the current flowing through the conductors.

2.Protection CTs measure the current and feed the necessary data to circuit breakers or relays to protect the systems in the event of faults or failure.

DFD Diode Failure Detector

Protects the machine against damage caused by failure of the rotating rectifier diodes

EL 200

EL 200 module performs two functions. When working as a maximum excitation limiter, it senses the field current output of the voltage regulator and limits the field current to prevent overheating. When working as a minimum excitation limiter, it senses the leading VAR output of the generator and limits any further drop in excitation and thereby preventing loss of synchronization

MVC 300

Manual voltage controllers are an integral part of a complete excitation system. MVC300 are utilized to control excitation in the event of an automatic voltage regulator failure. This device can completely isolate the automatic voltage regulator and manually control the generators output.

 

Environmental and Thermal Protection

Anti condensation heaters

Prevents condensation from forming within the machine where temperature and humidity

changes are prevalent. They reduce condensation or moisture in the air immediately around the

generator, when the generator is stationary. A separate power supply is required for the anti-condensation heaters.

RTD Resistance temperature detector.

An RTD is a solid state device, which has a linear increase in resistance directly proportional to the detected temperature.

RTDs may be used for detecting temperatures in the stator winding and the generator’s bearings.

Thermistor

Thermistors are positive temperature coefficient resistors - low resistance when detecting low temperatures and

high resistance (open circuit) when above the tripping temperature.

 

Other

Droop CT

The droop CT provides a current signal to the Droop circuit when connected to terminals S1 – S2.

is required to REDUCE CIRCULATING CURRENT and SHARE reactive load current sharing when in parallel with other Generators,

and/or the Grid.