SLA440ALE Diversified Electronics Protection Relays, SLA Series

• Monitors Delta or Wye Systems
• Monitors up to 480 VAC
• Fixed, Lock Shaft, or Screwdriver Adjustment
• Automatic Reset with Manual Option Available
• Plug‑in or Surface Mount Styles

With normal operating voltages applied in the proper ABC sequence, the internal relay will energize. When incorrect phase sequence or phase loss occurs, or the three‑phase voltages fall below the drop‑out voltages, the relay will de‑energize.

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.

Protects against:

• Phase Loss
• Under Voltage
• Phase Reversal