Where is the fuse for my AC unit?


Old 04-02-17, 10:18 AM
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Where is the fuse for my AC unit?

My AC unit stopped working. A couple days ago when I turned it on first time for this summer, nothing was moving and there was no sound from inside the house or the outdoor unit. I did some research and knew that I needed to check circuit breaker, fuse, capacitor, and transformer. The circuit breaker and the capacitor are fine. I have not checked the transformer yet. However, I could not find the fuse. I looked into the grey box by the side of the outdoor unit, and the fuse is not there (see the picture below). I pulled the breaker out (so the breaker is not in the picture) and the fuse is NOT on the breaker either. Where else can it be?Name:  grey box.jpg
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Old 04-02-17, 10:34 AM
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The fuse and transformer are in the air handler, usually located in your attic. Fuse will look like an automotive fuse and may be on a circuit board. Post the make and model of your air handler so the pros can give better info.
Old 04-02-17, 11:16 AM
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That is called a disconnect and has no fuses. The breaker for the AC will be located in the breaker box in your house. It will probably be a 30 amp breaker. Like Ray said check the 3 amp fuse in the furnace. Its on the control board.

Last edited by skaggsje; 04-02-17 at 11:19 AM. Reason: added
Old 04-02-17, 11:38 AM
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It's not your problem but just curious.... how did you check the capacitor ?

If you have a gas furnace inside the house then you may have a control board and fuse.
If you have a heat pump system there will not usually be a fuse inside the air handler.

We can tell you exactly if you post the make and model of the inside unit.

If the unit is in an attic location there may be a float switch somewhere attached to the drain pan or drain line. Look for that too.
Old 04-03-17, 04:49 AM
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Your pic shows a pull-out style disconnect.
The piece that inserts into the slot to complete the circuit is missing.
It could have been put somewhere inside the house to prevent someone from turning on power to the a/c.


I see now that you said you pulled out the insert to disconnect power to the a/c.
Your disconnect is a non-fused one.
As long as you have a properly sized breaker in the main panel the disconnect does not need to be fused.
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Last edited by GregH; 04-03-17 at 05:09 AM.

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