Seltrol is a stocking distributor of a wide variety of industrial automation equipment. We are located in South Carolina and service SC and NC. Our inside and outside sales staff are available to assist you with your application. We provide technical - application support for all of our products.
 

 

Ground Fault Sensors


Larger version - 17K - Click ‘AG’ Series sensors from NK Technologies protect people, products and processes from ground faults by monitoring all current-carrying wires in grounded single or 3-phase systems.

Operating Principle: Under normal conditions, the current in the hot leg of a two-wire load is equal in strength but opposite in sign to the current in the neutral leg. These two currents create magnetic fields that are also equal but opposite. When the wires are next to each other, the fields cancel, producing a "Zero Sum Current". If any current leaks to ground from one wire (Ground Fault), the two currents become imbalanced and the result is a net magnetic flux or field. AG Series ground fault sensors monitor this field and alarm when leakage rises above setpoint. This concept applies to grounded 3-phase delta and wye systems.

 

AG Series 5-950mA N.O. & N.C. Auto-Reset & Latching Download data sheet (pdf) file size: 579 Kb

Features

  • Operation to Match Your Application:
    Latching — For controlling contactors. Auto-Reset — For controlling shunt trip breakers.
  • Setpoint Options to Match Your Needs:
    Tri-Set —Field select 5, 10 or 30mA. Fast and convenient. (AG3 only)
    Single-Set —Factory adjusted setpoint. Specify 5–100mA (AG1) or 80–950mA (AG2) when ordering.
  • Compatible with Standard Equipment
    Works on 1F or 3F power. Controls standard shunt trip breakers or contactors. Tie into Emergency Circuits (EMO/EPO).
  • Isolated
    Magnetically isolated from the monitored circuit and control power
  • UL and CE Approval
    Accepted worldwide.

Applications

  • Personnel Protection (typically 5mA)
    Senses low fault currents and alarms to shut power before injury occurs.
  • Equipment Protection (typically 30mA)
    When personal protection is not an issue, select a higher setpoint to protect equipment or product.
  • Regulatory Approval
    Meet requirements by industry groups and governments for Ground Fault Protection.

Specifications

Setpoint Range
  • "Single-Set" Models
    		•  Factory adjusted and sealed (field adjustment possible)
    • AG1: 5–100mA, specify when ordering
    • AG2: 80–950mA, specify when ordering
  • "Tri-Set" Models
    		• 5, 10 & 30mA jumper select
    Output Isolated dry contact (solid state or relay, see Ordering Information)
    Output Rating • Solid State AC Switch: 1A @ 240VAC
    • Solid State DC Switch: 0.15A 30VDC
    • Relay: 0.5A @ 125VAC, 2A @VDC
    Off State Leakage None
    Response Time • 200mS @ 5% above setpoint
    • 60mS @ 50% above setpoint
    • 15mS @ 500% above setpoint
    Isolation Voltage Up to 1,250VAC (monitored circuit)
    Frequency Range 50–400Hz (monitored circuit)
    Sensing Aperture 0.75" (19mm) dia., up to 4" (100mm) dia. available, consult factory.
    Power Supply • 120, 200, 208, 220, 240VAC, 50-400Hz, operates from 55–110% of nominal voltage
    • 24VAC & 24VDC, operates +/–10%
    • Green LED = power (all models)
    Case UL 94V-O Flammability rated
    Environmental 5 to 158°F (–15 to 70°C), 0-95% RH, non-condensing
    Safety UL 1053, Class 1 Recognized, CE*

    *Most option combinations are UL recognized.

    Output Table

    Normally Energized Models (–FS Option)

      Protection from faults and loss of control power.

    		 Control Power Applied
    No Power No Fault Fault
    N.C. Normally Closed Closed OPEN Closed
    N.O. Normally Open Open CLOSED Open
    Normally Deenergized Models (–NF Option)

      Protection from faults only when control power is applied.

    		 Control Power Applied
    No Power No Fault Fault
    N.C. Normally Closed Closed CLOSED Open
    N.O. Normally Open Open OPEN Closed
    Latching (–LA Option)

      Latching models initially power up in the Reset position. If there is a fault or the test button is pressed, the output switches and is latched. The output will remain latched after the fault is cleared, even if control power is removed. To reset the output, apply a momentary contact across the "Reset" terminals (6–7).