Air Conditioner Help

[AnOldUR]

The only beer relevance is trying to keep things cool, but I'm hoping that there are people on HBT with air conditioner knowledge.

I don't know what this thing is, but an in-line fuse going to it blows in my air conditioner as soon as it's powered up. I have two other air conditioners that are the exact same model, but the vertical tube going up with that component on it isn't on either one.

The markings are:
P/N EBF57874202
OFF 4.5 MPa ON 3.2 MPa

What is it? Do I need it? Can I bypass it? How?

The place I bought it from wants $100 to just look at it.

 

[Zuljin]

I'm not sure what that is, but I know a bad capacitor can cause you problems. They're not expensive and are plug and play replaceable.

Of course, the capacitor may not be the root of your problem. I was replacing capacitors until I got a new fan motor. I had also replaced the breaker because it was bad too.

Edit: And being where that is, probably not a capacitor. May be a solenoid.

 

[AnOldUR]

I'm not sure what that is, but I know a bad capacitor can cause you problems. They're not expensive and are plug and play replaceable.

hmmm . . . there is a capacitor in the control box. And the problem started after we were hit with a surge. The only reason I suspected the component in the picture is that the fuse that keeps blowing is in a line that feeds directly to it. Could a bad capacitor be feeding it too much power?

I'm still curious what that thing is and why the other two units don't have it?

 

[AnOldUR]

A Google search found that the MPa unit might have something to do with pressure. The way it's just stuck at the dead end of a line has me thinking it might monitor the pressure in the line?

 

[onthekeg]

It looks to me like a sensor that won't let the compressor run if the refridgerant is low.

 

[ingchr1]

A Google search found that the MPa unit might have something to do with pressure. The way it's just stuck at the dead end of a line has me thinking it might monitor the pressure in the line?

MPa is a pressure unit, megapascel. Not sure what that pressure switch does for the unit without seeing the schematic for it. But if that is the only thing downstream of the fuse then it is likely the source of your issue. Unfortunately, it looks like there is no isolation on the line to replace it. I'm assuming those are refrigerant lines.

 

[DeafSmith]

For what it's worth, 4.5 MPa = 653 psi.

 

[AnOldUR]

Not sure what that pressure switch does for the unit without seeing the schematic for it. But if that is the only thing downstream of the fuse then it is likely the source of your issue.

I've got a couple of wiring diagrams. The ...714 is from the broken air conditioner. The ...704 is from a working unit. On the ...714 I found the H/P switch on the right side of the drawing. The other drawing looks identical except for not having the switch, but it does have the 250v/3.15amp fuse.

My thought is that I can by pass that switch. If the fuse still blows there must be a problem somewhere else. Do you think there's a serious danger in doing this?

Do you think the H/P Switch could be causing the fuse to blow or is the problem more likely to be somewhere else?

 

[ChuckO]

Check the capacitor first. A visual check to see if the case is bulged would be the first clue. I had one go out a couple of weeks ago due to power surges and a series of drop outs before the power died for a couple of days. Didn't find it until the power came back on but the AC unit didn't. Cost was about $55 for a new one to install myself.

To make a preliminary check on the switch, disconnect both leads to it, check each wire to the frame of the AC unit for a short circuit. If neither lead is going to ground the switch probably isn't your problem.

 

[ingchr1]

Do you think the H/P Switch could be causing the fuse to blow or is the problem more likely to be somewhere else?

The problem is more likely somewhere else. Not much to fail in the switch, unless it shorted to ground.