LLSV not opening

[targetman]

I've seen about a dozen systems this year that had problems with the vale not opening. These systems are all 410 and are a mix of equipment. On some I simply opened them manually. One system I replaced the LLSV, but found nothing wrong with the old valve. Another Tech at the shop also recently repacled a valve. The valve that I swoped out was a Sporlan ME14S250, MOPD 300, MRP 500, MKC-2 coil.

[ryan1088]

So power is applied and it's not opening? Solenoid problem or a mechanical problem with the valve? Help us help you!!

[hvacpope]

I dont recall ever finding a power to open solenoid valve stuck closed, typically either the coil fails or the seat leaks, maybe they were installed backwards?

[John Culpepper]

Hell, I had a suction line sevice valve that was frozen. 25 ton semi-h carlyle 06e. Had to brake out the big torch. And scrunch my a$$ in there and change it out. SUCKED.

[bunny]

I've seen about a dozen systems this year that had problems with the vale not opening. These systems are all 410 and are a mix of equipment. On some I simply opened them manually. One system I replaced the LLSV, but found nothing wrong with the old valve. Another Tech at the shop also recently repacled a valve. The valve that I swoped out was a Sporlan ME14S250, MOPD 300, MRP 500, MKC-2 coil.

The valve you list here is not appropriate for the pressures you'll see in a R-410A system....the MOPD rating is too low. You're likely running across situations where the valve isn't opening due to the pressure differential across the valve's port exceeding the valve MOPD rating.

Sporlan's R-410A solenoid valves will have a -HP at the end of the model number, and have a MOPD rating of 450 psi.

See pages 13-19 of the attached catalog.

[targetman]

The valve you list here is not appropriate for the pressures you'll see in a R-410A system....the MOPD rating is too low. You're likely running across situations where the valve isn't opening due to the pressure differential across the valve's port exceeding the valve MOPD rating.

Sporlan's R-410A solenoid valves will have a -HP at the end of the model number, and have a MOPD rating of 450 psi.

See pages 13-19 of the attached catalog.

Thanks Bunny. I suspected such, but I'm trying to see it and can't. Can you expain it to a third grader? LOL.

[bunny]

OK....system temperature satisfied, LLSV de-energized, and system pumps down.

If the LLSV is located at the condensing unit, the pressure on top of the valve's disc will be subject to whatever the ambient temperature is. This pressure is also exerted on the top of the enclosing tube plunger, which closes off the valve disc pilot hole when the valve is de-energized. If it's in the middle of summer, that might be over 100*F, to which the pressure would be in excess of 320 psi.

Depends on what the low pressure control set-point is as to what the pressure on the underneath side of the valve's disc is.

All that has to accurr is for the high side pressure vs the low side pressure at the time of pump down to be at/or greater than 300 psi, and the coil will not have enough strength to pull the plunger off the valve's pilot hole.

So, it's a simple force balance.

You've got a coil capable of pulling the enclosing tube plunger up into its magnetic field if the pressure the net pressure on top of the plunger is less than 300 psi.

[stanbyyourword]

i had one much earlier this year on a 404a walk in that is off the majority of the year, voltage and coil good, I put it down to poor lubrication , or stuck.

[Mopar-x]

I had two systems early this summer not sure of the part numbers but after a check with the supply house we got them from I found that they were only rated at 300 psi and would not open when energized I replaced them with properly rated ones and had no other issues for the summer.

[Andy Schoen]

A simple fix here would be to get the internal parts kit for an ME14S250-HP. The ME14S250 and ME14S250-HP have the same valve body

[targetman]

A simple fix here would be to get the internal parts kit for an ME14S250-HP. The ME14S250 and ME14S250-HP have the same valve body

Thanks Andy.

[Ansonf]

learn from the mistakes of others , and i will share my mistakes with those,
and we will all laugh and learn and be merry. Unless your just a bitter ole goat.....or your ego is fragile......or you just have a hard time with life.....in that case i will have to revert to my certificate of complete ******* , of which I earned a few years ago.

[Ansonf]

as*h*le