• Phase Loss
• Under Voltage
• Phase Sequence
• Monitor Relays
  
• Pump Index
• Pump Accessories and Hose Index

Phase SLA Manual

MONITOR/RELAY OVERVIEW

The ATC Diversified SLA Series is designed to protect 3-phase equipment against Phase Loss, Under Voltage and Phase Reversal conditions.  With normal operating voltages applied in the p[roper ABC sequence, the internal realy will energize (pick-up).  When incorrect phase sequence or phase loss occurs or the 3-phase voltages fall below the drop out voltages, the relay will de-energize (drop-out).  An LED indicator glows when all line conditions are normal.  Both Delta and Wwye systems may be monitored.  In Why systems, connections to neutral are NOT required.

Note:  When a phase is lost while the motor is running, a condition known as regeneration occurs where a voltage is induced into the open phase nearly equal in magnitude to the normal phase-to-phase voltage.  However, with the exception of lightly loaded motors, enough change is detected by the SLA to provide the required protection when properly adjusted.

PURCHASE MONITOR/RELAYS