Power circuit monitor for Joslyn vacuum switches

The Power Circuit Monitor (PCM) was developed specifically to monitor Joslyn Vacuum Switches. Monitoring the vacuum dielectric media in Joslyn switches is important for detection of failure to minimize service and repair. If a switch fails, the failure mode is usually loss of the vacuum dielectric in the interrupter contact module, which may not be immediately evident. If the condition is left undetected, the contact resistance increases until the module becomes overheated and causes an internal line-to-ground fault. This results in costly downtime.

The Power Circuit Monitor continuously monitors the system on the load side of the switch and provides an output signal if there is voltage on the load side when it is indicated to be mechanically open. The output of the PCM is a normally open relay contact.

Single phase or three phase sensing is available. PCMs must be used on systems for which the source is grounded and the primary of the furnace transformer is ungrounded.

PCMs are available for use with Joslyn systems energized at voltages up to 38.0 kV.



	Reduced Repair Cost
	Scheduled repair of the vacuum switch
	Reduced Repair Time
	Internal vacuum switch damage resulting from a vacuum interrupter failure is minimized
	Application Versatility
	Outputs can be used to operate an alarm on the control panel, open a Joslyn load break isolating switch, or automatically open the power circuit breaker
	Sensing Module
	Low voltage signal monitors any voltage which may appear when the vacuum switch is open
	Control Panel
	Relay contact will operate to indicate a malfunction of the vacuum switch system which may operate an alarm or breaker
	Self-Checking System
	Actuated when the switch closes and will result in an output signal

	Ordering Information
1	Provide the vacuum switch size - voltage and current ratings
2	Transformer size - kVA ratings
3	Actual system voltage

Joslyn Hi-Voltage Royce Thompson Fisher Pierce