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Okay so for our next post in my ‘Ask The AC Tech’ series. Jerry H. from Jackson, MS asks: “Why does my AC 5 amp fuse keep blowing?” I understand how annoying it can be but unfortunately, the solution can either be fixed up easily with a few checks, or it may take an AC specialist to make a visit.
In this post, I’ll look at some of the possible reasons for a blown fuse, what you can do to fix it, and some faqs.
Reason Why 5 Amp Fuses Keep Blowing on ACs
As with most air conditioner problems, a multitude of conditions might be causing your AC unit to “act up.” The following are some of the most prevalent reasons for blown 5 Amp fuses:
Low Refrigerant Level
Low refrigerant levels have been known to be the cause of blown AC fuses. Your air conditioner will have to work harder to maintain temperature if there is insufficient refrigerant. This can cause your air conditioner to blow a fuse due to overworking. Be sure to know what refrigerant your AC uses and have it filled to the recommended levels.
A Capacitor Has Failed
This problem might be the most troublesome for air conditioner users since it is difficult to diagnose with the untrained eye.
The capacitor in your air conditioner balances the unit’s electrical flow, but if it fails, it might cause your fuses to burst frequently.
Filter Is Filthy
Doesn’t it appear that the filter is usually to blame in many cases when your AC isn’t working? That could be exactly what is blowing the AMP. With an over-clogged air filter, your AC is working extra hard to pull in the air and will overstress the unit.
Maintaining a clean filter not only improves the quality of your indoor air but also prevents your air conditioner from overworking itself, which might lead to blown fuses!
Faulty Electrical Connections
Your air conditioner may be blowing fuses as a result of problems that originate and finish in the fuse box. It’s vital to note that fluctuating temperatures might cause these wires to stretch and shrink, thus impacting the electrical connection’s security.
Regardless of the reason, it is usually easier to let a professional detect the problem and give a lasting remedy so that it does not happen again in the future.
How Do You Fix a Fuse That Keeps Blowing?
Once you’ve located your blown fuse, there are a few steps to replacing it and resuming power. You’ll need a flashlight and a replacement fuse that’s the same size, amperage rating, and type as the blown one to execute this task.
If you’re not sure if you have the correct fuse, take the blown one to a hardware shop and have it matched. It’s critical to have an identical match since utilising one with a larger amperage will harm your entire home’s wiring and any associated appliances.
- To halt the electrical flow to the fuse box, turn off the main power.
- Locate the room where the outage occurred, which should have been previously tagged.
- Examine the fuses and circuits for the blown one mentioned above.
- Remove the blown fuse and replace it with a fresh one.
- Flip the tripped circuit from the centre to the off position, then back to the centre.
- Reconnect the main power supply.
Test the lights in the room that lost power after replacing the fuse or resetting the circuit breaker.
Try one or two appliances at a time; don’t overload the fuse by using too many at once, or you’ll blow another one. If you’ve tried everything and the blown fuse still won’t reset, consider contacting a licensed specialist for assistance.
How Can I Stop My Air Conditioner From Blowing Fuses?
Air conditioners, like refrigerators and freezers, have drawbacks. They draw a lot higher current during starting than they do during normal operation. They are also “start whenever I darn well choose” gadgets (unlike a table saw, which starts when the user hits the switch).
As a result, they must be connected to a separate (not shared with other things) circuit. All of the lights and half of the outlets in my apartment are on one circuit; you can imagine what would happen if I connected an air conditioner to that circuit.
First, ensure that your air conditioner is not sharing a circuit with anything else (look for whatever else stops working when the air conditioner blows a fuse).
Second, ensure that the circuit is appropriately sized for the air conditioner’s requirements. Do not just replace the fuse; the fuse is sized to match what the wires in the wall can safely withstand. Finally, a “slow-blow” fuse should be used. These are intended to pass a higher-than-normal current for a few seconds.
Should I Call an HVAC Company for AC Repair?
Being able to fix things around the house is something to be proud of, whether you’re a man or a woman. Your skilful work on a broken pipe, a clogged kitchen sink, or a window latch that simply won’t close makes you thrilled that you can fix your own house.
Repairing a broken air conditioner, on the other hand, should never be tried on your own! This is one of those instances when you should get in touch with the big guy.
Here are five situations in which you should contact AC repair.
- The air conditioner produces hot or warm air.
- The vents are not producing air or very little air.
- The air conditioner is humming loudly.
- Your electric costs have risen.
- The air conditioner is emitting foul odours.
What Kind of Fuses Should Be Used With Air Conditioning Systems?
You must get the correct size fuses for your air conditioning system. Allowing too many amps to flow to your condenser may cause it to fail and may be harmful to the device. In a pinch, you might use a fuse with a lower amperage rating than the ones you need, but never more.
Stop immediately if your air conditioner blasts when you turn it on. If the old fuses are larger than the new fuses, you will also need to purchase a fuse reducer.
These will slot onto each end of your smaller fuses and make up the physical size difference. To bypass the fuse, never place anything into the disconnect. This can cause significant damage to your unit and pose a risk to you and your family.
FAQs
How Long Do AC Fuses Last?
A fuse has a lifetime of up to 20 years. AC fuses are typically referred to as “slow-blow” or ‘time delay’ fuses. This means they are in use every time you switch the machine on and off, and will ultimately wear down owing to the strain of the operation.
How Do I Know If My 5 Amp Fuse Is Bad?
Take the fuse out of its holder. In rare circumstances, a little screwdriver may be required to remove the fuse holding lid. Examine the fuse wire. A noticeable gap in the wire or a black or metallic smudge within the glass indicates that the fuse has blown and must be replaced.

HVAC tech with over 30 years of experience. Retired and doing repair work on the side around Madison County, AL.