microchannel problems

[6howards]

is anyone having problems with nordine microchannel evaporator coils?

[mofotech]

I heard from Baloonie, that microchannel are very charge sensitive and one should charge them slowly.

[BaldLoonie]

Yea, haven't had any failures (yet) but you sure do have to be careful charging. They can have blockages that make it look undercharged. Then the blockage breaks free and suddenly you are way overcharged. Had issues with high head in heat mode with MC indoor coil. Nordyne came out with a fan cycle kit for heating. For piston matches, we usually find the coil piston is the wrong size so be sure to use the right one from the outdoor unit. Yesterday's job had 3 different pistons come with the outdoor unit and they needed piston was much larger than what came in the 1824 coil for a 2 ton.

[gravity]

Thanks for the good info Loonie!

[mofotech]

I am soon going to be involved installing as a team, 2 Philco units and both indoor and outdoor units have microchannel technology. Thank god, I am a member here and I was able to read your comments. Now I can advice my friends that day when we actually do the install. Not bad units they come with scroll compressors and HPS on the system. I wish it also had a LPS. I guess it can be added but damn we will then need a recovery machine and alot of patience!

[gravity]

why do you need all that?

Get a tee with depressor built into it. screw it to the suction service valve. screw the LPS into the tee side of the fitting. wire it in series with contactor coil and call it a day.

[mofotech]

That's awesome! I didn't think of that! I actually thought about using a piercing valve but then remembered that you can't leave those permanent and will need a stem valve installed where the original pierced valve is installed. Awesome! Thanks for the suggestion!

[DOGBOY]

you can try this. They come in all sizes. you just can't solder them on with the compressor pumping as it seems to remove your heat. Go figure.

http://www.hvacr-tools.com/product/c...dle-valve-5-16

[SBKold]

Don't think you should braze or solder on a line with refrigerant inside seems dangerous.

[mason]

Yea, haven't had any failures (yet) but you sure do have to be careful charging. They can have blockages that make it look undercharged. Then the blockage breaks free and suddenly you are way overcharged. Had issues with high head in heat mode with MC indoor coil. Nordyne came out with a fan cycle kit for heating. For piston matches, we usually find the coil piston is the wrong size so be sure to use the right one from the outdoor unit. Yesterday's job had 3 different pistons come with the outdoor unit and they needed piston was much larger than what came in the 1824 coil for a 2 ton.

The biggest problem I've seen is installer error on indoor coils, between the piston size and an epic run of retardation at our shop that had me looking at every MC coil we installed with a txv kit, they(our guys) never pulled the valve core from the equalizer tap.... One of them even said "how was I supposed to know", aside from having enough awareness to check... Here's your sign.

[MicahWes]

Don't think you should braze or solder on a line with refrigerant inside seems dangerous.

I don't enjoy it, but I have done it.

[DOGBOY]

The biggest problem I've seen is installer error on indoor coils, between the piston size and an epic run of retardation at our shop that had me looking at every MC coil we installed with a txv kit, they(our guys) never pulled the valve core from the equalizer tap.... One of them even said "how was I supposed to know", aside from having enough awareness to check... Here's your sign.

how was I supposed to know? was he serious? and what did he have to say after he saw the little tag that was there?

I made some of our installers mad when I found out that they were pumping down units to replace evaporators after I had used nitrogen to pressure test with. On their work orders it said nitrogen in system blow charge. They said how were we to know? I said I guess I will have to get the office girls to come back here one day and teach you guys (installers) how to read. They would not talk to for many days. but what could they say when in their own hands the work order stated nitrogen in system blow charge?

dogboy

[davidj001]

I don't enjoy it, but I have done it.

do you use low temp solder