Bit of an oddity

I've put in a A2W 4 ton HP (R410A) and I just wanted to confirm a couple things.
I'm getting the unit cutting out after about 5-6 min of operation, 5 min delay and back on again. Setpoint on the tank is not satisfied and outdoor temp is close to 14C
The most stable I can get for readings is:

98 psi suction and 136 discharge
4C SH and -6 SC
liquid side of the hx is 33 out and 29 in

I think she is overcharged a bit but cannot figure out why she is cutting out. Head pressure never gets anywhere near critical and she is liquid injected as well (but it never gets to the point of needing it)

Any thought?

I'm in the north of Newfoundland and have a flight booked in a couple of hours to get back to Toronto so I have to resolve at least the fridge side, hoping the rest is electrical (programming)

Where are you measuring high pressure, can you get a tap on the discharge line to verify pressure is ok?

I'm gone now and back in Toronto. The only place I could make any measurements is at the service valves. Pot temp did show at around 90C, the unit is tied into the manufacturer now by the interweb so they can see some of the issues. Not all, though.

Service valves may not give true discharge, especially if it is a split type outdoor, water flows alright?

still waiting for a model number and manufacturer -to see if i can find a manual:eek:

Quote:

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Originally Posted by install monkey

still waiting for a model number and manufacturer -to see if i can find a manual:eek:

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haha. No manuals worth anything for this model. Not in the same league as Mitsi or Fujitsu.

Google Ecologix

Quote:

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Originally Posted by MikeHolm

98 psi suction and 136 discharge
4C SH and -6 SC
liquid side of the hx is 33 out and 29 in

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These pressures and temperatures marked red does not have sense to me.
Where did you take that "discharge" pressure
Also, how did you calculated that negative subcooling temperature?

Give us all readings and where on system did you took them.

Also, you said that unit is "cutting out", but you did not say at what alarm (high pressure, low pressure, high discharge temperature, etc....) it is happening.

136-98=38 PSI
looks to me like pressure drop at evaporator (outdoor unit if it is split type) and belonging piping and maybe some kink on these pipes.

http://www.ecologix.ca/wp-content/up...-Heat-Pump.pdf
install manual- love the hand sketched wiring diagram

Quote:

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Originally Posted by install monkey

http://www.ecologix.ca/wp-content/up...-Heat-Pump.pdf
install manual- love the hand sketched wiring diagram

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This is a A2W, totally different beast with liquid injection.

Quote:

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Originally Posted by nike123

These pressures and temperatures marked red does not have sense to me.
Where did you take that "discharge" pressure
Also, how did you calculated that negative subcooling temperature?

Give us all readings and where on system did you took them.

Also, you said that unit is "cutting out", but you did not say at what alarm (high pressure, low pressure, high discharge temperature, etc....) it is happening.

136-98=38 PSI
looks to me like pressure drop at evaporator (outdoor unit if it is split type) and belonging piping and maybe some kink on these pipes.

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The pressure readings were taken at the service valves and the temps were 4-5cm closer to the comp but I couldn't get much closer to the comp. The Digicool gives SC readings in -C if the temp reading is higher than the high side bubble point, although the temps shown at that time were 0.8C and 8C so I'm not sure why it displayed the negative. Evap is just coil and TXV. and I'm quite sure there is no bad kink in the 7/8" or 1/2" lines.

There is quite a bit of monitoring on this unit (despite the crappy manual) and it has never given an error reading of any type. It just cuts out.

The manufacturer can get some readings via the net but I'm not sure what they can do.

136psi discharge!!- on r10a - pot goosed!

Oh, I hope not, this is where it is. It had a 60psi differential when running most of the time but the last run was only 10psi.

https://www.google.ca/maps/place/L%27Anse+aux+Meadows,+NL+A0K/@50.2445036,-57.0434481,5z/data=!4m2!3m1!1s0x4b83fe0a482d8213:0x7da6bd7dfe25d101?hl=en

Is that unit with 3 phase scroll compressor?

@mike

Quote:

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liquid side of the hx is 33 out and 29 in

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If you have 29°C entering and 33°C temperature of water leaving heat exchanger, which is in this case condenser, than you certainly cannot have discharge pressure of 136 PSIG (8.5°C dew point temperature for R410A). One of these two measurements is not correct.
By the laws of physics, discharge pressure at compressor must be at least above saturation temperature of 33°C (281 PSIG).

This pot has never got higher than perhaps 180psi discharge (measured at the service valves) and at that time condenser leaving temp was 43C and intake was 40C. Those liquid temps were measured by the unit controller.

Does this look at all like a gross over charge?

Mike, I still cannot see how discharge pressure could be that low with such condenser water temperatures.
To me, it looks like something is not right with these measurements.

I will have to get the owner to get a set gauges and temp probes and make some measurements. For me it would be a 3 hr flight and 3 hr drive to the property.

Since that is probably inverter compressor, all readings should be taken in TEST mode.
What is operational range (highest outdoor air temperature) for that unit?

It is a 2 stage comp, Copeland ZPS60k4E (or maybe 5E, cannot remember). It started off running around 23A and at worst went up to 33A. Definitely not right.

Highest outdoor it should see is 30C and lowest is -40C but it will be off at that point and there is a backup electric boiler.

My two cents (or whatever the euro is worth these days)

Get line tap on discharge or tee off HP switch
disconnect back up heater in case it's acting the maggot

take pressures temps then, does sound like compressor is knackered but maybe if you find cause of HP trips you can salvage it

If the manufacturer pays for a trip to do the work, I'd be happy to go but it will be $2000 just to get there and back.

Al, the backup isn't tied in to the HP as yet, no matter what yo mammy says (so no need to kill her)

Making an educated guess.

either expansion device is totally open (is EEV or TEV)
or
the compressor internal relief valve is passing

ya sounding like the pot is tripping on the clixon over load protector, the cycling times seems to jive with that