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Littelfuse Current Monitoring Relays Transducers
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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.

See datasheet for operation detail.

Property (Mouseover for details) Value
Input Voltage (V) 120VAC
Input Tolerance (%) -20% - 10%
Input AC Line Frequency (Hz) 50/60Hz
Output Type Electromechanical relay
Output Form Isolated SPDT
Output Load Rating (VA) 10A resistive @ 240VAC; 1/4 hp @ 125VAC; 1/2 hp @ 250VAC
Time Delay Range 0.5 - 50s adjustable
Time Delay Tolerance (%) Guaranteed range
Response Time (ms) ≤75ms
Trip Delay Sensing on Startup (s) Fixed: 0.1 - 6s in 1s increments
Trip Point Range 2 - 20A adjustable
Undercurrent Trip Point <250mA turns typical
Setpoint vs Ambient Temperature and Operating Voltage (%) ±5%
Sensor Type Toroid through hole wiring for up to #4 AWG (21.1 mm2) THHN wire
Sensor Mode Over and undercurrent trip points (window current sensing)
Sensor Tolerance Guaranteed range
Current Sensor Range Steady - 50A turns; Inrush - 300A turns for 10s
Sensor Frequency (Hz) 45/500Hz
Insulation Resistance ≥100 MΩ
Isolation Voltage (V) ≥2500V RMS input to output
Surge Protection IEEE C62.41-1991 Level A
Circuitry Encapsulated
Type of Detection Peak detection
Life Mechanical - 1 x 106; Electrical - 1 x 105
Termination Type 0.197 in. (5 mm) terminal blocks for up to #12 (3.2 mm2) AWG wire
Mounting Method Surface mount with two #6 (M3.5 x 0.6) screws
Operating Temperature -40° to 60°C (-40°F to 140°F)
Storage Temperature (F/C) -40° to 85°C (-40°F to 185°F)
Humidity 95% relative non-condensing
Dimensions 3.50 x 2.50 x 1.75 in. (88.9 x 63.5 x 44.5 mm)
Weight (lbs/g) ≅6.4oz (181g)