Fault Thrower - Single phase to earth fault making switch

The fault thrower provides a means of deliberately introducing a phase to earth fault in order to ensure remote end tripping of a circuit breaker, assuming pilot wires are not available for inter-tripping. The need to operate the remote circuit breaker can be due to equipment faults, such as thermal protection or low level fault currents that cannot be detected by the remote protection

Features

A typical application is with transformer feeders to enable the remote feeder breaker to respond to the transformer local fault detecting relays, such as Buchholz protection, local earth fault protection, etc.

The unit is based on the design of the Horizon circuit breaker and uses a single phase vacuum interrupter driven by a magnetic actuator for fault initiation. The switch is housed in an aluminium tank, dielectric insulation is provided by SF6 gas.

Connection to the system is achieved by either a separable connector or open terminal bushing. Manual release of the switch is available within the control cubicle housed under the tank. The fault is ‘thrown’ through the aluminium tank, two earth points are provided for safely earthing of the equipment steel work and to provide a fault path.

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Ratings

Rated Voltage

kV

38

Short Circuit Making Current

kA

25

Short Time Current Withstand

kA 3secs

25

Peak Withstand Current

kA

63

Peak short circuit making current

kA

63

Impulse Voltage Withstand

kV

170

Frequency

Hz

50 / 60

Power Frequency Withstand Wet / Dry

kV 1min

80

Internal Arc (EATS 41-36)

kA 1sec

31.5

Fault Making Time

Ms

190

Endurance at 25kA

 

50 makes

Control Voltage

V dc

110 (48 & 220)

Ambient Air Temperature

ºC

-50 to +50

Weight

Kg

500

 

Applications

The Fault Thrower's main application is for:

  • Utilities

get in touch

Contact HSS

+44 (0)1495 223001

+44 (0)1509 611511

+ 61 7 3888 2333

what we've done

case studies

SSEN - Horizon Framework

Electricity Northwest Ltd - MediPark