A/C calls

[Minuteman]

Have you been getting a lot of Air Conditioning calls? We do. Yesterday I went on three, today two. Now, I'm not an Mechanical Contractor, but we get a lot of A/C disconnect replacement and branch circuit OCP failure calls.

One of the calls yesterday was at an old hotel downtown. It was a 30-amp,V delta disconnect and the C phase fuse was burned up completely. The B phase fuse was damaged, ad was not in the fuse holder properly. This disco was one of four that were improperly tapped to a 150-amp fused disco. I replaced the damaged disco and gave him a price to replace the 150-amp disco with a panel, but I doubt he will do it. interesting side note, the phase colors were Yellow/Red/Black in all the building.

While I was there, the Mechanical Contractor that referred me called and asked me to check a unit on an adjacent building. I checked the disco for voltage and opened the cover for the contactor, pushed it in and the unit came on while I held it. Looked at the low voltage wiring for the Thermostat and found a splice that was so sun damaged, a wire nut failed. Repaired the splice and tapped it up with some 33+ and was on my way.

A call today was because a A/C journeyman I know replace a condenser fan motor, but when he closed the disco, there was no voltage. He checked the panel and the A/C breaker has voltage, but no voltage at the disco, so he left. I arrived and noticed that the 30-amp breaker for the A/C had voltage, and the 30-amp breaker for the dryer was not quite in the on position, so I turned it off and back on. I closed the disco, and the dryer breaker tripped again. I looked at the wiring for the condenser motor and there was a direct short from the miss wiring going to the fan capacitor. Changed the wiring and relabeled the panel.

Now there was a point, in the last two stories that I told, were I could have confirmed the presence of voltage and stopped. Question, do many of you stop or go beyond a little and troubleshoot the equipment?

 

[quogueelectric]

I have taken extensive hvac courses but I do not have a freon handlers license or a machine to reclaim it. I understand the entire process and can alleviate most small problems but I am not changing out condensing units or anything like that. But I could if I had the gas I have a manifold an evacuation pump and all the knowledge but I would have to steal refrigerant and I wont do that. It is always the heat of summer for the attic calls.

 

[ramsy]

Have done two A/C trouble calls. Always get into it because I'm learning, and not real busy anyway.

First case was a deteriorating keypad and no cooling in a Carrier split unit. Tried to bypass keypad, shorted control wires with no success. Cleaned disconnect, verified voltage, replaced control wirenuts, and engaging the fan relay --at the end of a 10 foot stick of PVC--. Ultimately passed it to an A/C contractor who charged $800 for a new keypad, and coolant recharge.

Second case was a 50A breaker that had tripped occasionally and now always before starting. Clamp meter showed 100A on #8 for a second or two at the panel. There was a compressor in the outdoor condenser/fan unit. Paid $25 for my first Megger tester. A 1000v Megaohm test confirmed a faulting compressor; 2000 Ohms from phase to equipment ground.

Can't replace hermetically sealed units, can't cut tubes, evacuate, recharge, or sweat copper, and no license for refrigerant, so after doing my part the baton was passed to the A/C guy.

Wish I knew how to test those fan capacitors.

 

[iwire]

Here the HVAC guys handle HVAC calls at least to the point where the problem is external to the HVAC equipment.

 

[macmikeman]

I get a lot of service calls to install new wiring for new ac equipment. As for servicing- one ac contractor I work for alot calls me in sometimes to help troubleshoot the big chiller units electrical problems. the shipping out to Hawaii seems to loosen electrical connections sometimes. One time I went thru the entire system controls inside a 70 ton package unit, only to find a small vacume valve that the ac contractor failed to open per the startup directions. He was kind of red faced about that.

 

[ptonsparky]

Back in '76, when I was an beginning A/C service tech, I believe the study guides I had indicated 90% of problems with A/C was electrical.

 

[Minuteman]

Here the HVAC guys handle HVAC calls at least to the point where the problem is external to the HVAC equipment.

Here too, it's just that this time of year puts a lot of stress on the systems and there are too few HVAC techs.

 

[bbaumer]

Friend worked for a contractor who serviced Sears sold window AC's.

Got a call on a small window unit. 120V. "A/C won't turn on".

Arrived on site. A/C not working. Portable radio plugged into same outlet as A/C. Radio playing music.

Checked out unit all the while listening to the crappy radio station. Can't find anything wrong. Puzzling.

Radio becoming more annoying and is getting in the way. Unplug radio to shut it off move out of the way. Radio is STILL playing!

Arrrrrgh! Breaker was tripped. Radio on battery power.

 

[brantmacga]

i don't get any hvac service calls; in my state, hvac contractor's licenses are also electrical licenses for anything related to hvac equipment, including installing new circuits.