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ATC SLA-440-ALE Monitor/Relay, 430-480 Adjustable, Lock Shaft Adjusted, Surface Mounted, 8 Screw Terminals

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$349.72

$ 99 .00 $99.00

In Stock

About this item

  • Delta or Wye Systems
  • Fixed, Lock Shaft, or Screwdriver Adjustment
  • Available up to 480 VAC (625 VAC with "E" Style)
  • Several Enclosure Styles


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 proper ABC sequence, the internal relay will energize (Pick-Up). When incorrect phase sequence or phase loss occurs or the three-phase voltages fall below the drop out voltages, the relay will de-energize (Drop-Out). On models featuring indicators, the LED glows when all line conditions are normal. Both Delta and Wye systems may be monitored. In Wye systems, connections to neutral are NOT required. For UL Listed units, with field wiring terminals, copper wire with 60°/75° C rating must be used for control circuitry connections. 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. The SLA Series is UL Listed under File Number E55826.


Matthew Lankheit
Reviewed in the United States on March 25, 2024
Worked great on a coil grabber for an overhead crane.
John W.
Reviewed in the United States on August 3, 2023
Part shipped and arrived as promised but part was bad out of the box.
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