ECSW Series AC Window Current Sensor & Control 0 pages

"Window Current Sensor ECSW Series
Current Sensor nn

DescriptionOperation

Reset: Remove input voltage or open latch switch. If zero current detection is selected, the unit will reset assoon as zero current is detected. When the input voltage is applied, sensing delay on startup begins and the output transfers (if normallyenergized 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 outputrelay remains in its normal operating condition and both red LED's are OFF. The green LED glows when theoutput 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 trip delay, the relay transfers to fault condition
state. If the current returns to normal levels (inside the window) during the trip delay, the red LED goes OFF, the
trip delay is reset, and the output remains in the normal condition. Operation With Zero Current Detection Enabled: If the current decreases to zero within the trip delay period,then zero current is viewed as an acceptable current level. The unit's output remains in its normal operating
state. This allows the monitored load to cycle ON and OFF without nuisance tripping the ECSW. Zero current
is defined as current flow of less than 250 milliamp-turns. Note: When zero current detect is selected, the
latching operation of switch SW2 is canceled; the output will not latch after a fault trip. Overcurrent & Undercurrent(Window Current) Sensing Adjustable Overcurrent & Undercurrent Trip Points Current Sensor is Included 10 A SPDT Isolated Output Contacts Notes on Operation: LED IndicatorsApprovals: 1) There is no hysteresis on the trip points. The overcurrent and undercurrent trip points should be adjustedto provide adequate protection against short cycling.2) If the upper set point is set below the lower set point, both red LED's will glow indicating a setting error.
3) If zero current detection is selected (SW2 ON), and the system is wired to disconnect the monitored load,the system may short cycle. After the unit trips, the load de-energizes, and zero current is detected. TheECSW resets, and the load energizes again immediately and may be short cycled.4) The sensing delay on start up only occurs when input voltage is applied. When zero current detection isselected, the trip delay must be longer than the duration of the inrush current or the unit will trip on theinrush current. Selector Switch Typical Pump or Fan Protection Circuit Operation Window Current Sensing: With the ECSW connected as shown in the diagram, a load may be monitoredand controlled for over and under current. The ECSW Series' on board CT (CS) may be placed on the line or
load side of the contactor. The ECSW selection switches are set for zero current sensing (see Selector SwitchSW2) and the output selection is normally de-energized (see Selector Switch SW3). The input voltage (V) isapplied to the ECSW continually. As the control switch (FSW) is closed, the input voltage (V) is applied to the
motor contactor coil (MCC), and the motor (M) energizes. As long as the current remains below the overcurrentand above the undercurrent trip points, the ECSW's output contacts remain de-energized. If the load currentshould rise above or fall below a trip point, for the full trip delay, the normally open (NO) contact will close,
energizing the control relay (CR) coil. The CR normally closed contact (CR1) opens and the MCC de-energizesand CR latches on through its normally open contacts (CR2). Reset is accomplished by momentarily openingthe normally closed reset switch (RSW). Not UsedLatched
Zero I
Output
Normally
Energized ON OFF >
SW1SW2
SW3

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Connection

Mode Selection Switches SW1 = Latched or Auto reset selector OFF - Automatic reset after afault ON - Output relay latches after a fault trips the unitSW2 = Zero current detection - (below 250 mA)
OFF- Zero current detection
disabled
ON- Zero current detection
enabledSW3 = Output during normal operation
OFF- Output relay de-energized
ON - Output relay energized
The ECSW Series of single phase, AC window current sensors includes adjustable overcurrent and undercurrenttrip points. Detects locked rotor, a 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 automaticallyreset. Remote resetting of a latched output by removing input voltage. The unit includes switch selectable zerocurrent detection and normally de-energized or energized output operation. Time delays are included to
improve operation and eliminate nuisance tripping. Note: If the current falls tozero within the trip delay, the
ECSW remains de-energized.
The sensing delay on startup
occurs when input voltage isapplied therefore trip delaymust be longer than the
duration of the motor's inrush
current. The external latching
relay CR2 is required in this
system to prevent rapidcycling. A timer can be addedto provide an automatic reset. MC = Motor Contactor M = Motor F = Fuses OL = Overload RSW = Reset Switch
FSW = Fan or Float Switch CR = Control Relay
CS = Current Sensor MCC = Motor Contactor Coil Note: The output is normally de-energized. >
ECSW2B0112.12.05 8.6 Low Voltage Products & Systems >

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