Asco 4820, User Manual, Page: 29 / 51

Operation
ASCO Model K875A Outdoor Load Bank
4-7
The “trip point” value = I(sense) can be applied to the controller terminals J1 and J2, using a
separate current source.
There are two methods of field adjusting the trip point of the current sensing relays:
Method 1 - Using a separate (0-5 Amp) current source without the current transformer
Method 2 - Rough adjustment (Approximation Method)
Method 1 - Using a separate (0-5 Amp) Current Source without Current Transformer
1.
Disconnect all sources of power to the Automatic Load Shed Controller. (Control voltage
and current sense input)
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W A R N I N G
When disconnecting the current transformer, the secondary terminals
must be shorted. The secondary of an unshorted current transformer
can exceed several thousand volts.
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2.
Apply 120 VAC, 60 Hz control power J1(10-12) (see schematic).
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W A R N I N G
There is lethal high voltage within the control enclosure.
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3.
Using a controlled current source, apply the setpoint current (from secondary current
calculation) to Controller terminals J1(1) and J1(2).
4.
Turn the relay knob labeled THRESHOLD past the trip point; then decrease until the relay
trips on, indicated by LED illuminating.
5.
Reconnect all wires previously removed.