Manufacturing for this product has been discontinued. As an alternative, please refer to the 3 Series relays.

The Type SLJ21A is a static synchronism check relay which is designed to permit closing of a breaker only if the angle between the voltages on the line and bus sides of the breaker is less than a set angle for a set period of time. Also included are two voltage measuring circuits to check line and bus voltage conditions. The relay is mounted in a size S2 drawout case. 
 

Applications 

• Bus or line synchronism check

Protection and Control

• Synchronism check operation
• Adjustable time delay
• Adjustable phase calibration range
• Instantaneous undervoltage