A031_F: Open Fuse
Status
This is a critical fault. The furnace will not operate in any mode.
Description
The fuse has been opened. This usually occurs when there is a 24VAC short to common or ground on the low voltage side of the transformer.
Expected Operation
A
conductive fuse is always expected be present for normal operation. If however, the
fuse is sensed open, the IFC will:
- Ignore all requests. Possible operation in progress finishes in the same way as if the request was removed.
- Alarm “A031_F Open Fuse” is declared.
- During the time the fuse is sensed open, treats the rollout limit switch, main limit switch, heat
assisted limit control and both auxiliary inputs as closed to assure
correct reaction on the open fuse condition (otherwise the switches would
be falsely sensed open).
Once the fuse is sensed conductive again, the IFC shall revert back to normal operation and the alarm will be cleared.
Cause
An electrical short from low voltage (24VAC) to ground or common has occurred.
Solution
Repair the short circuit condition and replace fuse.
