© 2018 Littelfuse Protection Relays & Controls

www.littelfuse.com/

Rev: 1-A-062716

Protection Relays

Current Monitoring Relays and Transducers

www.littelfuse.com/ecs

ECS SERIES

Description

The ECS Series of single-phase AC current sensors is a universal,

overcurrent or undercurrent sensing control. Its built-in toroidal

sensor eliminates the inconvenience of installing a stand-alone

current transformer. Includes onboard adjustments for current

sensing mode, trip point, and trip delay. Detects over or

undercurrent events like locked rotor, loss of load, an open heater

or lamp load, or proves an operation is taking place or has ended.

Operation

Input voltage must be supplied at all times for proper operation.

When a fault is sensed throughout the trip delay, the output

relay is energized. When the current returns to the normal run

condition or zero, the output and the delay are reset. If a fault is

sensed and then corrected before the trip delay is completed,

the relay will not energize and the trip delay is reset to zero.

Adjustment

Select the desired function, over or under current sensing.

Set the trip point and trip delay to approximate settings. Apply

power to the ECS and the monitored load. Turn adjustment and

watch the LED. LED will light; turn slightly in opposite direction

until LED is off. Adjustment can be done while connected to the

control circuitry if the trip delay is set at maximum. To increase

sensitivity, multiple turns may be made through the ECS’s

toroidal sensor. The appropriate trip point range is determined by

multiplying the amperage load by the number of turns/passes

through the toroidal sensor. When using an external CT, select

a 2VA, 0-5A output CT rated for the current to be monitored.

Select ECS adjustment range 0. Pass one secondary wire

lead through the ECS toroid and connect the secondary leads

together.

Features & Benefits

FEATURES

BENEFITS

Built-in toroidal

current sensing

Eliminates need to install stand-alone

current transformer and provides isolation from

monitored circuit

Encapsulated

Protects against shock, vibration, and humidity

Adjustable mode, trip

point and trip delay

Provides flexibility for use in many applications

10A, SPDT isolated

relay output

Allows control of AC voltage loads

Accessories

P1015-13 (AWG 10/12), P1015-64 (AWG 14/16),

P1015-14 (AWG 18/22) Female Quick Connect

These 0.25 in. (6.35 mm) female terminals are

constructed with an insulator barrel to provide

strain relief.

Wiring Diagram

V = Voltage

I> = Overcurrent

I< = Undercurrent

W = Insulated Wire Carrying

Monitored Current

Relay contacts are isolated.

Arrow on the toroid points

toward the load.

Current Sensors

Ordering Information

See next page.

Rev: 1-A-101218