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ACQ550-CC Packaged Drive with Bypass
Installation
Motor Overload Relay
The ACQ550 with Bypass includes a motor overload relay to provide thermal motor
protection. It is connected in both drive and bypass modes of operation. For motor
full load currents up to 80 amperes, the Motor Overload Relay is an adjustable trip,
bimetallic overload relay with a class 20 trip characteristic. Above 80 amperes, the
Motor Overload Relay is an adjustable trip, electronic overload relay with selectable
class 10, 20 or 30 trip characteristic.
Suggested Settings
Current
Set the current adjustment to the value of the full load current shown on the motor
nameplate.
Auto/Man
It is recommended the overload relay be set to the Manual Reset mode of operation.
In the Auto Reset mode, the Overload Relay contacts re-close automatically when
the bi-metals of bi-metallic versions cool or when the timer function within the
electronic versions times out. If power is applied and the switches and contacts in
the control circuit are commanding the motor to run, the motor will start as soon as
the overload relay resets.
Class
The class 20 setting on the electronic overload relays would be the appropriate
choice for the majority of the motors used in North America.
Resetting the Overload Relay
In the event an overload relay set in the Manual Reset mode trips, it is necessary to
open the door of the enclosure and push the Reset button on the front of the
overload relay to reset it.
WARNING! If power is applied and the switches and contacts in the control
circuit are commanding the motor to run, the motor will start as soon as the
overload relay resets. Use caution when manually resetting the overload relay
to make sure it is safe to start the motor.
