Electronic Bypass Controller Installation and Commissioning Guide
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4.8.2 Automatic Bypass on VFD Fault
In the Automatic Bypass on VFD Fault Mode of operation, when the electronic bypass
control board senses a VFD fault it will automatically switch the motor to Bypass
operation. This function is enabled by DIP switch 1, position 1, placed in the OFF
position.
Automatic Bypass will operate in both the VFD Auto and the VFD Hand Modes of
operation. The functionality in each mode is exactly the same.
CAUTION:
Use caution when selecting this mode as the motor will accelerate to full
speed anytime the VFD experiences any type of fault condition.
4.8.3 Emergency Bypass
In the unlikely event of a failure of the electronic bypass control board, an emergency
bypass jumper may be repositioned to enable the electronic bypass to be operated
as a full voltage fixed speed starter. The emergency bypass jumper is located on
the component side of the door-mounted control board. To change this jumper,
use the door interlocked disconnects to remove power from the electronic bypass
before opening the enclosure door. Remove the four (4) mounting screws from the
control board. With the component side facing you, move jumper J6 from the open
position (normal) to the emergency position. When the enclosure door is closed and
the disconnect is in the ON position, the bypass contactor coil will be immediately
energized closing the contactor and starting the motor at full across-the-line voltage.
The motor thermal overload protection is disconnected in this mode.
To exit Emergency Bypass, turn the door interlocked disconnect to the OFF position.
Power to the bypass contactor coil will be removed and the contactor will open
disconnecting the motor. Remove the control board from the door and move jumper
J6 from the emergency position to the open position. Close the enclosure door and
place the door interlock in the ON position. Control will be returned to the control
board for VFD or bypass operation.
When in Emergency bypass mode the motor thermal overload relay is disconnected
and will not protect the motor from an overload condition. Damage to the motor may
occur.
