Electric arc furnace switch - VBU-T Transmaster

VBU-T Transmaster Electric Furnace Switch

The VBU-T Transmaster Electric Furnace Switch controls the operation of electric furnaces, which require large amounts of power under heavy duty conditions. The VBU-T was developed to eliminate costly and frequent circuit breaker maintenance. The VBU-T is a low cost, heavy duty vacuum switch designed to deliver maintenance-free switching of electric furnaces.

The VBU-T switch provides reliable and safe interruption. Interruption takes place inside a sealed vacuum interrupter which eliminates all external arcing, contamination of contacts, and generates no hazardous gases. The interrupter is enclosed in a housing and insulated with the field proven Joslyte™ solid dielectric foam.

The VBU-T's rugged, compact design makes this unit ideal for transformer vault installation. The VBU-T operates uniformly on all power factors and is available for system voltages from 69kV up to 138kV.



	Long, Maintenance-Free Life
	Low Cost Installation
	Lightweight units are self-contained and completely factory assembled, requiring no special foundations or costly supports
	Vacuum Interruption
	No gas, oil, or other medium is required to maintain electrical properties
	Safety
	No hot exhaust or ionized gases are liberated during interruption and the switch contains no explosive, volatile materials
	Auxiliary Contacts
	Eight heavy-duty auxiliary contacts are provided for remote indications, control and interlocking of other furnace functions or equipment
	Weatherproof Control Cabinet
	Interconnection wiring is provided at easily accessible internal terminal strips remote from high-voltage lines
	Easy to Test and Monitor
	Condition can be determined without dismantling by a high potential withstand test and contact resistance measurement

Ideal Complete Furnace Switch System

1 RF-2 Air Switches

2 Joslyn Motor Operator

3 Power Circuit Monitor

VBU-T Transmaster Switch Ratings
Nominal Voltage	69 kV			115 kV	138 kV
Continuous Current (A)	600	1000	1500	600	600
Momentary Ratings (kA) (RMS amperes, asymetric)	40	50	50	40	40
Impulse withstand open gap/line to ground (1.2x50 positive wave kV)	350			550	650
Maximum 60-cycle withstand line to ground kV	Dry 175 Wet 175			Dry 293 Wet 281	Dry 350 Wet 350
Fault Interrupting Rating (kA)	4			4	4

	Ordering Information
	Specify Transmaster switch by selecting voltage class and continuous current from ratings table above.
Each Transmaster switch package includes:
	Standard control with 6 digit electrical counter to monitor operations
	Undervoltage cabinet for 120 VAC 50/60 hertz
	Undervoltage trip and antipump control circuit feature
	Electrically operated relay package providing eight auxiliary contacts for control interlocking

Joslyn Hi-Voltage Royce Thompson Fisher Pierce