10 ton trane package unit

[Xerokross]

Hello everyone, My name is Terry, I'v been a tech for a couple years now, nice to meet everyone.

I was needing some help with a trane 10 ton heat pump package unit I'm working on Model WSC120E. The unit has proper charge and runs great in cool mode no problems there, when the unit is switched into heat mode my second circuit pulls a vacuum on the low side and trips the low pressure cutout, it also freezes after the txv and distributing lines leading into the outdoor coil. While it is frozen up I tried to put the sensing bulb in hot water to open up the valve and but it stays frozen do I have a bad txv or is there something else I should be checking, thanks ahead of time for and advice.

[ksefan]

Sounds like a txv issue to me. Get your post count up and apply for Pro membership, it’s free and you get lots of good training info.

[timebuilder]

Did you confirm the charge is correct while in cooling mode?

[Xerokross]

Yes the charge is correct in cooling mode, checked with subcooling charging curve chart from the unit manual.

[timebuilder]

In that case I would probably agree with ksefan.

[timebuilder]

Full disclosure: I haven't touched a Trane heat pump RTU in probably 11 or 12 years.

[buford]

Is that a danfoss valve brazed onto the dist body and the real skinny cap tube line to bulb?

[Xerokross]

It doesn't say Danfoss on the powerhead but when I type in its number online a Danfoss page is one of the first that shows up, it does have a very small line to the bulb the line doesn't appear to be kinked or damaged, same for the bulb. It also has an external equalization line.

[Xerokross]

Hello everyone, just so this might be of some help to people in the future I wanted to give this thread a resolution. I replaced the TXV and the unit runs great now in cool and heat mode, also replaced the dryer. Thanks again to everyone for the help.

[timebuilder]

Thanks for the closure....we appreciate it.