Hey HVAC Guys! Need Help...

[Killer95GT302]

I'm looking to buy a place and the inspector found that the AC compressor is not turning on. I know this can be a million things, but to help number it down I found something odd...

There are some wires that are clipped and hanging outside the unit (See Pictures). Tracing them inside the unit, they lead to what seem to be things on the refrigerant lines.

Any idea what these wires are/were for and why they are clipped? Is this the reason the compressor isn't turning on? I checked the AC breaker in the house and outside by the unit, they were OK.

Any input is appreciated!

 

[zak88lx]

Check the capacitor to ensure it hasn't gone bad.
Visually you may see bowing on the ends from expansion.
It's a fairly cheap fix if that is the problem.
We had the same problem on our Lennox unit.

Be careful when handling the capacitor, as they can give you a really good whack if they still have juice.

 

[zak88lx]

Also, check to see if the unit has a AC service disconnect panel mounted outside.
Inside is a plastic handle that can be flipped to change the unit from ON to OFF.
It's possible they turned it to off for storage.

 

[Thump_rrr]

Those are your low and high pressure safety switches.
If you look closely you will notice that one has a red reset button on the top.
this is the high pressure switch.
The other is the low pressure switch.
They are typically wired in series with a time delay relay and then go on to the contactor (compressor motor starting relay).

The purpose of the pressure safety switches is to stop the compressor if a high or low pressure event occurs to protect the compressor.

If the condenser fan ( fan on top of outdoor unit) fails the pressure will rise opening the high pressure switch. this is to prevent the compressor from overheating. Since the high pressure switch is manually resetable it would definitely get your attention.

The low pressure switch would open if there is a lack of refrigerant, if the indoor blower fan wasn't working or the indoor air filter was blocked causing a lack of airflow. It would restart automatically if the problem went away.

In your case these safety items have been bypassed most likely by a cheap ass owner who didn't want to spend the money to fix his equipment properly.

The equipment most likely has other issues and from the photos looks to be quite old.

 

[Killer95GT302]

Awesome info guys, thanks a lot!!