520CP115 - 520CS / 520CP Series

Littelfuse Current Monitoring Relays Transducers
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OBSOLETE 06/2017  - The 520CS and 520CP are fully-programmable, microcontroller-based, current-sensing devices designed to monitor 3-phase pumps. The 520CP is designed to work with motors that have ramp-up times of 4 seconds or less. The 520CS has a programmable motor acceleration time that can be set from 0-50 seconds.

Both current monitors protect 3-phase motors from:

  • Overcurrent
  • Undercurrent
  • Current Unbalance
  • Rapid Cycling
  • Single Phasing
  • Phase Reversal
Property (Mouseover for details) Value
Input Voltage (V) 100 to 130VAC
Maximum Input Power 5W
Input AC Line Frequency (Hz) 50/60Hz (50Hz will increase all delay timers by 20%.)
Input Current Range (A) 5 Amps (maximum)
Output Form SPDT
Output Load Rating (VA) Pilot Duty: 480VA @ 240VAC; General Purpose: 10A
Timing Accuracy (%) 25%
Rapid Cycle Timer (s) 0 - 500s; Programmable number of restarts; 0 1, 2, 3, 4 or 999 for unlimited
Restart Delay Range On power up: 0 - 500s; after all faults: 2 - 500m
Trip Delay Range 2 - 50s for all faults except phasing faults
Trip Point Accuracy (%) ±2%
Overcurrent Trip Point Undercurrent trip point to 5A
Undercurrent Trip Point 0.00 to overcurrent trip point
Reverse and Single Phase Trip Delay (s) 0.5s
Motor Acceleration Time Operating Point (s) 4s
Mounting Method Four #10 or #12 screws (3/4 in - 1 in in length)
Operating Temperature 0° to 70°C (32° to 158°F)
Dimensions 8.25 in H x 5.25 in W x 3.25 in D (209.6 x 133.4 x 82.6 mm)
Weight (lbs/g) 2.2 lbs. (35.2 oz. 997.9 g)