Swimming Pool Heat Pump Fault

Hi everyone, I'm new to the forum so please point out if I make any mistakes or bend rules.

I'm a Refrigeration/AC Mechanic that has been asked to check a friends FairLand Vertical Swimming Pool Heat Pump. I haven't much (if any) experience with these things. The unit runs for @ 10 mins then cuts out on 'PPO6 - Compressor Outlet Overload Protection'. Unit is charged with R407C. On my manifold Gauges I am getting a compressor suction pressure of between 50-60psi and a compressor discharge pressure of 140-150psi (seems a little low for 407C). However the discharge pipe temperature (before and after Diverter valve) is @ 95'C! Fan runs OK, Pool Pump is OK and Pool water filter is not blocked. The Diverter valve seems to be in the correct position as compressor discharge gas is flowing directly into the heat exchanger/condenser. Ice is forming on the distributor pipes that feed the evaporator coil. Do these running pressures sound correct? I'm not convinced it's short of gas, but then can't explain why it's cutting out on Compressor Discharge temperature Protection either. Is there some hidden gauze/filter at the heat exchanger inlet that could be blocked that I've overlooked, causing poor water flow in the Heat Exchanger? Any help with what common faults cause this condition would be greatly appreciated.

Many thanks in advance

Hi Smartus and welcome,

95ºC sounds a bit on the high side.
Normally when not enough refrigerant get back to the compressor the discharge temperature start to creep up.
Could be due to a lack of refrigerant but also because something isn't right on the evaporator side of things, like lack of airflow through the coil for example.
Best thing to do would be to hook your gauges up to the system and see what the sub cooling and superheat are doing.

Happy hunting,

:cool:

Check as viking suggests, you could be right with poor water flow, is the evaporator air cooled? If so check it's not blocking up.

al

welcome to the forum by the way:))

Thanks for the welcome guys and thanks for the advice.

Regarding the Subcooling I can get a gauge line on between the Heat Exchanger/Condenser outlet and the Electronic Expansion Valve so it's impossible to check that. I'll check the Superheat and see what I'm getting and see what I'm getting. Although that'll be on the suction pipe rather than the Evap outlet as there aren't any other system access points. I'll clean out the Evap as well and check that it's nice and clean before doing anything else. I'll let you know how I go...

Cheers.

Hi Smartus
check sub cooling with a digital thermometer and compare with discharge pressures SDT.
High discharge temp.. faults could indicate a tied compressor and bypassing internally, the internal relief could have let go previous and is still leaking. 150 psig discharge nominal 10 bar SDT +30' C ish
Welcome to the forum by the way.

http://www.procopiuk.co.uk/downloads...New%202008.pdf
click on the link for manual:o

Hope you have this sorted by now! Sounds as though it was water flow - possibly too slow.
All the pool heating systems I install always have a by-pass valve so that the water flow through the heat pump can be adjusted. It's amazing the difference even small adjustments can make.
With new machines, and (hopefully!) correct refrigerant charge and superheat, I balance the water flow by monitoring discharge pressure and current drawn by compressor. Can take a few return visits, but I can a good starting point this way.
Buen suerte, Graham

You could also check the discharge outlet thermistor for calibration

how would he have a suction press of 50-60 and a discharge of 140 with no power to it??

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Originally Posted by MaryD

Did you check if the circuit breaker has been tripped? or the fuse has blown? Or call a Heat pump repair expert you can check this out for info's :D

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That would be some call out. Vegas to Australia!!!!

just another gimp trying to promote a buisness, which is pointless because not many people will see it- better off walking round vegas naked wearing a bill board!

Did you check if the circuit breaker has been tripped? or the fuse has blown? Or call a Heat pump repair expert. :D

Quote:

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Originally Posted by MaryD

Did you check if the circuit breaker has been tripped? or the fuse has blown? Or call a Heat pump repair expert. :D

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Dumb.........

Quote:

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Originally Posted by MaryD

Did you check if the circuit breaker has been tripped? or the fuse has blown? Or call a Heat pump repair expert. :D

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There is this nifty thing between your ears, when you use it you avoid sounding like you have a stiff breeze going between said ears, do pray tell how you'd get the pressures he is giving with no power?

Perhaps you'd best step out and let the adualts talk and the guys with training, I'm glad your an eager sales man but this isn't the place for you!