AC OVERCURRENT & UNDERCURRENT CAH, COH & CUH Series

The CxH Series is an AC current sensing relay that is available in three versions: CAH Series--can detect either an overcurrent or undercurrent fault (selectable); COH Series--overcurrent only; and CUH Series--undercurrent only. The currentcarrying wire is run through the built-in current transformer and can be looped multiple times for greater sensitivity. These relays include user-adjustable settings for Fault Trip Current & Time Delay on Fault Trip as well as an LED to indicate fault condition. The encapsulated construction offers protection in harsh environments. Applications such as monitoring for locked rotor or load loss condition, open heater or lamp, and process control are perfect for these products.

Overcurrent Sensing
After input voltage is applied & the sensing delay on power-up (tS) is completed, the unit will begin sensing for a fault condition. A fault will occur when the monitored AC current (I) goes above the Fault Trip Current setting & remains above the Reset level for a period longer than the adjustable time delay period (t). The LED will turn ON immediately and the relay will energize after the time delay on pick-up (t) is completed. The relay will de-energize & the LED will turn OFF when the monitored AC current goes below the Reset level.

Undercurrent Sensing
After input voltage is applied & the sensing delay on power-up (tS) is completed, the unit will begin sensing for a fault condition. A fault will occur when the monitored AC current (I) goes below the Fault Trip Current setting & remains below the Reset level for a period longer than the adjustable time delay period (t). The LED will turn ON immediately and the relay will energize after the time delay on pick-up (t) is completed. The relay will de-energize & the LED will turn OFF when the monitored AC current goes above the Reset level.

 

Features
  • Monitors AC current
  • Can be used as either an overcurrent or undercurrent relay
  • Three separate adjustable Fault Trip Current ranges covering 0.5 – 50 amperes
  • Built-in current transformer allows easy access & multiple loops for increased sensitivity
  • Adjustable time delay on fault trip
  • LED indicates fault condition
  • 10A SPDT output contacts
  • Encapsulated for protection in harsh environments
  • Pilot Duty Rating

 

Downloads

Document File Type File Size Download
CAH, COH, &CUH Series Datasheet PDF 351 KB