Central air conditioner fuse

by Dadan

Central Ac breaker

Central Ac breaker

Central Ac breaker Fuse Metal Box Time Delay Cartridge Fuses Fuses Holder

What is central air conditioner fuse?

An air conditioner fuse prevents any parts of HVAC to overload or overheat.

Is a safety (device) that tells the HVAC unit, ok - you supposed to draw 30 Amp. If any part of you draw more than 30 Amp, I’m gonna turn you off.

The fuse box should be in the line of vision; it should be within REACH from the condenser unit location. The fuse for HVAC unit is Heavy duty time delay cartridge fuses. The fuse is within the fuses holder.

The within REACH disconnect is in metal box. It is either a handle that you pull out, within this handler, there is two fuse in the fuse holder. Or there is breaker.

If there isn’t disconnect box within REACH, there should be breaker box within 5 feet from the condenser unit. The condenser switches are within the breaker box.


Indoor and outdoor unit have TWO different fuses switch. Indoor unit has it owns fuse or breaker switch, the same for the outdoor unit.

Question and Answers

Can I put two different Amp fuse in the fuse holder?

Is it ok to have 2 different size fuses in the outside disconnect box? I have a 20 amp and a 30amp fuse. Could this cause the compressor to blow? The max amp is 30/30 on the AC cover


No. If the original fuse were 30 amps. You should replace it with another 30 amps fuse. The fuse should be time delay fuse. It should say that in the fuse.

“Both fuses should be 30 amps. The fuses should be dual element, slow blow type. You likely will not hurt the system, but the 20 amp fuse will most likely open at the most inopportune time.” By Chester

5 amp fuse in air handler blows

The 5 watt fuse blows in the air handler. This only happens when the outside unit kicks on. The air handler will run if there is no power to the outside unit. Changed stat wires and it still blows the fuse.


Sounds like you have a short between the outdoor unit and the control board on the air handler. Your technician needs to check the "Y" circuit for a short. By Chester

Condenser unit blow fuses right away. Why?

If the condenser unit is blowing fuse, there is part within the condenser unit which is pulling more than it Amps. The reason it blows fuses could be: the condenser unit is short to ground, electrical wire is loose, high discharge pressure, bad compressor..etc

If you put fuses in and it blows, don’t put anymore fuses. Have it checks by a tech – yeah, it cost money. Btw, central ac unit is on its own circuit

Comments for Central air conditioner fuse

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AC Compressor NEW
by: Anonymous

Unit is getting power but not generating cool air.
Fan on unit is not turning.

circuit breaker NEW
by: Anonymous

do I need a separate breaker for central air ?

question NEW
by: Richard

If my AC condenser has a 30 amp fused disconnect outside by the unit, can it have a 50 amp breaker in the panel?
I guess I just don't understand why it needs a fuse to act as an overcurrent protection device at the disconnect, and another one at the main panel?
Any help would be greatly appreciated.

central furnace only works in on position then kicks breaker
by: Jr. R

I recently had my blower motor and capacitor replaced, when I had to use the central ac unit.

Now that its cold out I'm trying to use the furnace and it will only work when the thermostat is in the on position but blower will not kick on when I put it on auto.

The coils are heating up in auto position but blower will not kick on. It only works if I put it on ON and then it kicks the breaker after about 10 minutes.

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