Dropped leg to condenser unit. - Contractor Talk - Professional Construction and Remodeling Forum

**Teetorbilt** · 03-04-2009, 01:55 PM

The unit is an '05 Trane XR12 and the condenser quit. A quick check revealed no 240V at the disconnect line side, I'm getting 124V on L1 and 17V on L2. The breaker reads 245V so the problem is between the breaker and the disconnect.

The airhandler and heat are working fine.

How is this unit wired? J-box at the airhandler? Anything else I need to know before I tear out the contents of an entire closet to get to the access?

mickeyco · 03-04-2009, 02:38 PM

Loose or broken connection, take a look for an old fuse box in between maybe (sometimes left when upgraded to breakers), ran into that before, replaced the fuses with copper pipe.

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flashheatingand · 03-04-2009, 08:33 PM

The air handler and heater may be working fine, but the lower voltage is rough on the equipment. Lower voltage, higher heat on the wire, yadda yadda, yadda. I wouldn't take apart the wiring connections inside of the a/h. It would be easier to Disconnect the other side of the wiring. If there is only three wires, It's l1 to one lug &l2 to the other, and a ground. Pretty basic. Good luck

**Teetorbilt** · 03-05-2009, 03:25 AM

I know about the LV, I live in FL. I was looking for some one that knew Trane before I had to crawl up into the attic. I'm assuming that the J-box is there, want to know if it's inside or outside of the airhandler.

I'm certified/licensed in marine and have a friend licensed in commercial/refrigeration. My thought is that there was a bad meter connection. Here's why, we both checked the lines to the main house circuit breaker using his meter and mine, no 240. The PC came out, pulled the meter, replaced and now there is 240!

Now I just have to get it to the condenser unit. Work has been slow for almost a year now and as much as I'd like to pay a HVAC guy to come and fix it, I don't want to go on Beenie Weenies for a week.

flashheatingand · 03-05-2009, 10:04 AM

When you say j-box, I believe you are talking about the point where the home-run ties in with the appliance. That connection is inside of the air-handler cabinet. Sometimes, someone will wire a disconnect before the air-handler. But, the appliance terminals are inside of the cabinet.

flashheatingand · 03-05-2009, 12:49 PM

You do know there should be two separate home-runs. One for the air handler, and one for the condensing unit.

**Teetorbilt** · 03-05-2009, 08:58 PM

I'm calling the A/C co that installed it tomorrow and cleaning out the closet tonight. Case closed.

flash, the home was built '79-'80 and my A/C buddy said the same thing about the home-runs but he's all commercial. There is only a single 60A breaker dedicated to the HVAC system and the home passed inspection.

**Teetorbilt** · 03-14-2009, 08:41 PM

Found it! The original installers relied on the wire nut to make a 4 wire connection and it was loose. The plastic part of the nut had completely melted away and the inner spring part was only holding 3 of the wires together, the wire to the condenser unit being totally free.

Strip long, twist tight with pliers, cut off excess THEN nut. Add tape if you're so inclined. That's the way that I was taught.

flashheatingand · 03-14-2009, 11:27 PM

You found it? Good for you. I don't claim to be a sparky, but, around here, it's two home-runs. If it works, and it's your home and you are happy, cool. However, I would ask the sparkys how they would tie all the wires together. I would think one should use some special lugs or something other than wire-nuts. Nothing too technical, just something more substantial than wire-nuts.

Well, thanks for posting the end result. Because a similar situation could happen to me.