Daiken A/C Fault - HELP

[CSNW]

Hi, I today came across a fault Iv never experienced. I have a Daiken cassette split system on R410a. In heating, both the suction and discharge pressure rise very quick, both up to over 500psi. Eventually the unit detects a fault and the compressor cuts out.

When in cooling, both the suction and discharge pressures fall, the discharge pulls down into a vacuum, and the suction to around 5psi. Compressor doesn't sound at all healthy. However I don't see that being the cause. My first line of thought was a blockage somewhere. But usually a high discharge and low suction etc etc is a sign.

My next thoughts where to reclaim the refrigerant, weigh it out see if its correct. Disconnect refrigerant lines and make sure pipe work and evaporator coil are clear. Then push nitrogen through the outdoor unit and see the outcome.

Any help would be appreciated. cheers, Craig 

[joe-ice]

Sounds like a blockage of a filter at exv or the exv itself is not opening .

[CSNW]

Thanks, Daiken Technical also mentioned this. I think firstly ill try loosen the head on the Expansion Valve, I know if it becomes to tight it won't allow refrigerant to flow through. Cheers mate.

[Hamza Alg]

did you find out what the fault was ?

[rac.eire]

had a similar problem on a york unit,faulty 3 way valve

[sacoolman]

Hi,have you checked your 3 way valve to see if its sticking?

[parr_spike]

i had a similar problem on an lg split, in heating suction and discharge went straight up to 600 psi and cut out, in cooling then both sat at around 150 psi. i also suspected 3 way valce to be at fault but they didnt want to wait for parts on site and had me swapping it with an identical unit on site that isnt used that much.

when firing this unit up once repositioned i had exactly the same pressures , almost equal in heating and cooling. this lead me to think that surely both units cant have the same fault ( it was friday and i never stuck my gauges on the working system to check it :rolleyes:)

i rang lg and they said it was normal to have the same pressures on both sides as the expansion is at the outdoor not the indoor and therefore in heating the suction pressure is actually the discharge and the liquid line giving similar pressures and i should only have 5 psi diffence in cooling as the lines are suction and expansion line. i find this hard to believe and still have doubts the system is working correctly. any thoughts?

[r.bartlett]

i had a similar problem on an lg split, in heating suction and discharge went straight up to 600 psi and cut out, in cooling then both sat at around 150 psi. i also suspected 3 way valce to be at fault but they didnt want to wait for parts on site and had me swapping it with an identical unit on site that isnt used that much.

when firing this unit up once repositioned i had exactly the same pressures , almost equal in heating and cooling. this lead me to think that surely both units cant have the same fault ( it was friday and i never stuck my gauges on the working system to check it :rolleyes:)

i rang lg and they said it was normal to have the same pressures on both sides as the expansion is at the outdoor not the indoor and therefore in heating the suction pressure is actually the discharge and the liquid line giving similar pressures and i should only have 5 psi diffence in cooling as the lines are suction and expansion line. i find this hard to believe and still have doubts the system is working correctly. any thoughts?


When it's early in your career what marks you out is the willingness to push yourself. The 'friday' quip marks you out as someone who isn't bothered too much. Hence you have not learnt anything from the experience and have come away even more baffled than you went in...A working unit is a training aid. 10 minutes would have given you a base to be a fault finder not a parts swapper


http://www.achrnews.com/articles/the-basic-refrigeration-cycle

You will no doubt take offence and come back and say how hard you work etc etc. But sadly you're skimming learning (and probably have always done) which reflects in your position.

Look to someone such as Marc5180 who was in a very similar situation when he stared and has turned out be one of the best by his willingness to work and study hard.

also check the filters are clean and the refrigerant charge is correct


Good luck.