Air Conditioning - outside unit keeps burning fuse

HI,
My outside unit keeps blowing one of the 2 fuse next to it and does not run at all. Any suggestion is appreciated

Are you using time delay fuses?

And what maximum size fuse does the compressor nameplate call for? What size and type of fuses are installed? When did this problem start?
Doug

Very many things can blow a fuse. Post thus far address the most obvious. How long has this been happening. Could be easy fix, could be big bucks.

OK, from what I can see there is no time delay fuses. There are two 30A fuses in the box next to the outside unit and when one blows you have to replace it which is very inconvenient since I have replaced it like 6 times so far. Now on the unit it says that it should have 35A, but keep in mind that this setup has been working like this for the past 13 years, so I don't know if having a 30A fuse when it calls for 35A is the reason. But My concern is at this point is the fan which does not run and I wonder if that is bad would be the cause of all of this. One technician charged me $145 to tell me that the fuse box needs to be replaced, which I know is nonsense, and another who charged me $100 says I need a new unit. So you can see this pretty confusing. I am wondering if there is a way to test the fan and the compressor independently, and rule out the fact that they are bad or not.
Thanks for your attention.

Why do you think replacing the fusebox is nonsense?

because I think if there was a problem with that box the breaker inside would have tripped.

But I must say changing that box is not expensive, and since it's a pain to change the fuse every time, I was thinking to replace it with one with a breaker for easier reset.

I am wondering if there is a way to test the fan and the compressor independently, and rule out the fact that they are bad or not.

You can disconnect either the compressor or the fan, and see which one is blowing the fuses. Don't run the the compressor for more than, say, 30 seconds without the fan.

Normally, there is a disconnect switch at the outside unit. Protection, whether fuses or a ckt breaker, is provided at your main panel. So, I'm a bit unfamiliar with your set up. I would expect to see time delay fuses, if fuses are used at all, for the compressor.
Doug

It wasn't stated completely...but most A/C units require a time delay fuse, since the initial draw is higher than the normal load while running. Also as equipment ages its not uncommon for it to draw more amps than it did when new.

The simplest and easiest would be to get correct size time delay fuses and see how it works..what would that cost $6-7?

You need to address the non running fan of course...could be as simple as a $25 capacitor or a $75 fan motor.

Did either of the techs bother to check the amps when the unit was running? Did they bother to put new correct fuses in?

Neither one of the techs could have checked the amps when the unit was running, because it was not running. All they tried was putting new fuse which kept blowing. I am wondering does the capacitor also effect the fan and if the capacitor could be causing all of this.
You mentioned a time delay fuse. What is that, something that just goes in where the regular fuse is?

You need to check for a dead short to ground. Could be any of the components in the condensing unit. You need a meter that reads continuity or ohms to check for shorts.

Around and round goes the dog chasing it's tail. Thanks to skip for mentioning METER.

Should be pretty easy to distinguish between the leads to the fan and the comp. Mark wires and disconnect the fan. Turn the power on and push in the contactor.

Disconnect the comp and push in the contactor.

Which one blowes the fuse?

You need a new tech. A tech always asks why until the real problem is found. No guessing.

You mentioned a time delay fuse. What is that, something that just goes in where the regular fuse is It is a type of regular fuse. Without getting to technical there are two flavors of fuses Fast Blow (no time delay) good for pure resistive loads and Slow blow (time delay) good for inductive loads like motors where inrush current at starting far exceeds the fuse rating. Both fuses look identical and are interchangeable but the labels tell you which they are. You may see "NON" on the fuse. That would be the wrong fuse. Read the label tell us what it says. If only one blows on the same side every time it could be you have a time delay fuse on the side that doesn't blow. JMHO but we need to settle the fuse issue before testing further.