My first blown transformer! (I'm so proud)

[HVAC_Austin]

Went to jump out a water source heat pump today using R to Y1 (the maintenance guys would of had to start it using their automated system, and they typically don't want to be bothered). It still wouldn't energize so I decided to take the jumper off (with 460 volts still flowing through). One side of my beautiful little magnetic jumper wire (those $10 yellow ones) popped off and instantly stuck to some other metal, apparently grounding the transformer. Sparks and smoke...kicked the breaker....so I ended up bothering the maintenance guys anyway (didn't know where the breaker box was).

Hope this makes your day seem a little less worse.

[jmsmars1]

I did better than that yesterday. I got my assignments in the morning and I accidentally went to the billing address instead of the place I was supposed to go (laundromat franchises). I did tune ups on 3 machines and was almost completely done, only thing left was to wash the condensers so I started to do the paperwork before my hands got wet and discovered my mistake then. I called the office and told dispatch what happened, and she said they didn't have tune ups done at that location. No wonder the indoor coils were so dirty. I went ahead and finished, had the attendant sign the paperwork, and drove 30 minutes to the right location, 3 hours behind schedule LOL.

[Capz]

Austin, you need electrical training. You must be very careful jumping out any voltage above 24v if you do it at all. Never take high voltage for granted especially any high amperage circuits. What kind of circuit flows 480v thru R & Y1 connections. Sounds like you shorted the primary side. What was the secondary voltage?

[jayguy]

what? no pictures?

the worst thing that i heard happen was a 7.5 ton compressor changeout at a mall. the guys i used to work with changed the compressor in a unit that was working and was for the space next door to the failed unit!

[HVAC_Austin]

Austin, you need electrical training. You must be very careful jumping out any voltage above 24v if you do it at all. Never take high voltage for granted especially any high amperage circuits. What kind of circuit flows 480v thru R & Y1 connections. Sounds like you shorted the primary side. What was the secondary voltage?

460 volt primary, 24 volt secondary, result of mistake was an open primary coil. I do have electrical training, but I got in a big hurry and attempted to do something which I have not been trained to do yet. Won't do that again.

[mason]

what? no pictures?

the worst thing that i heard happen was a 7.5 ton compressor changeout at a mall. the guys i used to work with changed the compressor in a unit that was working and was for the space next door to the failed unit!

I worked with a guy who was a good tech but I got a call to help him on a compressor changeout, got there and he was taking out a compressor on a RTU he had installed the day before but on the wrong unit that didn't have any problems, he was pretty upset about it but the paperwork was not clear and he didn't diagnose the original unit.

Then there was my last company where a resi pack unit was pulled out and rolled off to the side until the HO came out and freaked because it was the wrong unit, they had another pack around the corner. They were told the wrong unit on that one.

[Joehvac25]

I did better than that yesterday. I got my assignments in the morning and I accidentally went to the billing address instead of the place I was supposed to go (laundromat franchises). I did tune ups on 3 machines and was almost completely done, only thing left was to wash the condensers so I started to do the paperwork before my hands got wet and discovered my mistake then. I called the office and told dispatch what happened, and she said they didn't have tune ups done at that location. No wonder the indoor coils were so dirty. I went ahead and finished, had the attendant sign the paperwork, and drove 30 minutes to the right location, 3 hours behind schedule LOL.

Been there lol. I was trying to find a house in a small town and the only house without a number on it was the one I thought could be it. Door was unlocked, they had an oil furnace and that's what I was looking for. I had it pulled apart and the nozzle size didn't match what was on my sheet (we keep track of that stuff), so I did some snooping and realized it was the wrong house lol.

[LKJoel]

Magnetic jumper?

[klee7013]

We had one last summer.
compressor went out and we got an okay to install a new condenser . These guys were not thinking. We had three guys go over to change the CU out because it was 12' plus in the air so we had to use our Genie lift and such. They pumped it down and threw the unit off the stand to the ground below. Come to find out they tore the wrong unit out. They tidied up the panels back out and put it back on the stand and installed the new condenser in place of the bad. Somehow the condenser that got a nice drop is still running today. The invoice had the model and serial number of bad system but their explanation was the new condenser was so big so we changed out the bigger unit WTF. 13 seers are bigger than 10 seer. Uhh enough of my rant it was a very stressful day


o yeah and one time a tech installed a compressor at the wrong house so he had to put the old back in their unit and go install the new one next door. He didnt check the address on the house with the ticket

[Capz]

460 volt primary, 24 volt secondary, result of mistake was an open primary coil. I do have electrical training, but I got in a big hurry and attempted to do something which I have not been trained to do yet. Won't do that again.

You tend to remember mistakes made when it involves a big **S spark and tripped breaker.
And there is no trainer or training which will show you how to jump 460v connections. Not in my book or experiences anyway. Take care.

[Brent Ridley]

Been there lol. I was trying to find a house in a small town and the only house without a number on it was the one I thought could be it. Door was unlocked, they had an oil furnace and that's what I was looking for. I had it pulled apart and the nozzle size didn't match what was on my sheet (we keep track of that stuff), so I did some snooping and realized it was the wrong house lol.

This happened once when I was helper (many years ago). We were dispatched to a specific address; the number was something like 234...we went to 324 or something like that. It was a service call and the unit was broken! Frozen up. They let us in, we fixed, and left....billed the original customer. We only figured out our mistake when the right homeowner called wanting to know where we were!

[Joehvac25]

Magnetic jumper wires just seem like an accident waiting to happen, they are made to stick to metal and we know how that turns out.

[HVAC_Austin]

Magnetic jumper?

They sounded like a good idea, but like Joehvac25 says they apparently can cause problems if you're not careful. Will think very carefully before using them again. Picture below.

[Joehvac25]

This happened once when I was helper (many years ago). We were dispatched to a specific address; the number was something like 234...we went to 324 or something like that. It was a service call and the unit was broken! Frozen up. They let us in, we fixed, and left....billed the original customer. We only figured out our mistake when the right homeowner called wanting to know where we were!

Nice! Your loss his gain lol! I had a call Friday, I was sick and it was close to after hours and you guessed it its been out for days! The son of the owner opened the door and kind of didn't want me to come in, I was like am I at the right house? He said yes but know ones here, I just blew by him and was like well someone called me and I just drove a half hour with a migraine and after throwing up so let me in our I'm leaving!

[Core_d]

Magnetic jumper?

[hvac69]

Had a jumper fall off R terminal in a brand new York RTU during start up years ago. The other side stayed attached to W1, well the loose end swung right into the line side of the contactor. Big flash, lit the instruction manual on fire which was still in the electrical cabinet. Blew apart every wire that was on the line side attached by flag connectors, blew the relay board, the ignition module and shorted the white wire in the thermostat cable when it blew a hole out of the insulation and against a metal stud. Sh.... happens, just hope it isn't at 4 on a Friday.

[PMARS2345]

I use these jumpers, never had a problem.

[hurtinhvac]

You can't prevent stuff like this - though I only use my mags on stats as they are typically so hard to jump with the little contact realestate.

Had my regular gator jumpers out today in an OU out on low pressure; with live 230. Two contactors, two run caps, one start cap and a 521. Wires and contacts everywhere; in between thunderstorms and 8' up on a ladder on a wicked slope. Could have easily had an incident.
At one point I was holding the contactor in with a nut driver way up high and reaching down to throttle in juice down low. If OSHA would have saw that I would have been in big trouble. Hovering HO was impressed and kept wanting to get his hands in there and help; adding to the fun.

The nature of the trade, nothing more...nothing less. The only reason I don't have a similar tale is I having been doing it long enough.

[jason12000]

Thanks, you guys made my bad day muuuuch better.

[hotrodrob]

Is it just me or do others here not trust the diagnostics of techs before you. Me out of curiosity will verify the diagnosis before a major repair. Its been more than once ive been sent out to change a compressor to find something like a bad cap or low charge. One unit was just low enough to work for a short period and then cut out on thermal. Tech before me added a hard start kit and proceeded to condem the comp. before i haul half my van onto the roof i threw a set of gauges on it and it was low. Found leky shader. Replaced core and added gas. Unit has been fine for 3 years now. Property owner said i was the first tech that even took a set of gauges on the roof. Needless to say the tech before me no longer works for us and i personally take of all the properties for this owner.