© 2016 Littelfuse Protection Relays & Controls

www.littelfuse.com/

Rev: 1-A-062716

Protection Relays

Current Monitoring Relays and Transducers

www.littelfuse.com/ecsw

ECSW SERIES

Description

The ECSW Series of single-phase, AC window, current sensors

includes adjustable overcurrent and undercurrent trip points.

Detects locked rotor, jam, loss of load, an open heater or

lamp load, a broken belt, or loss of suction. LED’s aid in trip

point adjustment and provide fault indication. The built-in

toroidal sensor eliminates the need for an external current

transformer. The output can be electrically latched after a fault,

or automatically reset. Remote resetting of a latched output

by removing input voltage. The unit includes switch selectable

zero current detection and normally de-energized or energized

output operation. Time delays are included to improve operation

and eliminate nuisance tripping.

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

LED indication

Visual indication for trip point adjustment and fault

indication

Multiple switch

selectable features

User selectable zero current detection, latched,

normally de-energized, or energized output adds

application flexibility

Adjustable trip delay

Eliminates nuisance tripping and prevents

rapid cycling

Isolated 10A, SPDT

output contacts

Allows control of loads for AC or DC voltages

Operation

When the input voltage is applied, sensing delay on startup

begins and the output transfers (if normally energized is

selected). Upon completion of the startup delay, sensing of

the monitored current begins. As long as current is above

undercurrent trip point and below the overcurrent trip point

(inside the window), the output relay remains in its normal

operating condition and both red LED’s are OFF. The green LED

glows when the output is energized. If current varies outside

the window, the associated red LED glows, and the trip delay

begins. If the current remains outside the window for the full

Wiring Diagram

Current Sensors

L1

N/L2

MC = Motor Contactor

M = Motor

F = Fuses

OL = Overload

RSW = Reset Switch

FSW = Fan or Float Contacts

CR = Control Relay

CS = Current Sensor

MCC = Motor Contactor Coil

V = Voltage

I> = Adjustable Overcurrent

I< = Adjustable Undercurrent

W = Monitored Wire

∆T - AdjustableTrip Delay

Ordering Information

MODEL

INPUT VOLTAGE

TRIP POINT ADJUST. TRIP DELAY

SENSING DELAY ON STARTUP

CONNECT.

ECSW3LABT

24VDC

0.5 - 5A

0.150 - 7s

0.1s

Terminal blocks

ECSW4HBHT

120VAC

5 - 50A

0.5 - 50s

6s

Terminal blocks

ECSW4LADT

120VAC

0.5 - 5A

0.150 - 7s

2s

Terminal blocks

ECSW4LBHT

120VAC

0.5 - 5A

0.5 - 50s

6s

Terminal blocks

ECSW4MACT

120VAC

2 - 20A

0.150 - 7s

1s

Terminal blocks

ECSW4MBHT

120VAC

2 - 20A

0.5 - 50s

6s

Terminal blocks

ECSW4MBGT

120VAC

2 - 20A

0.5 - 50s

5s

Terminal blocks

ECSW6MBHT

230VAC

2 - 20A

0.5 - 50s

6s

Terminal blocks

If you don’t find the part you need, call us for a custom product 800-843-8848