APAC 65KW Ducted

[icemakerman]

Merry Xmas All
i have an old apac 65KW 2 Stage A/C Approx 32.5kw per stage recently burnt out Recip compressor...Manuerop mt 161... replaced with manuerop Scroll compressor SCZ 161...was told difference in capacity was approx 2KW...replaced burn out drierin suction line .. found leaks at suction line solenoid(Capacity Control???)removed solenoid alltogether. evac and charge and appeared to have failed tx (Danfoss TE5 )Replaced power element made no difference BTW suction pressure was below 200KPA (R22) found orifice size to be #2 should be #3 .... Changed orifice to #3 Suction pressure came up to 220KPA Disch\arge pressure @ 1600KPA ***the system is 2 stage. stage 1 is the concern ..have system set up so stage 2 still runs when stage 1 in fault. TX Valve is set up correctly (26mm spring length of cage)replaced power assy again in case new one faulty ,system still the same ... at my wits end HELP!!! (also coil restriction is 100Pa if this helps )

[cool_tech]

hello icemakerman, any liquid line driers in the system if so are they blocked. haver you tried adjusting tx valve?

[paul_h]

So you replaced the suction burn out drier? Was there already on in there?
Just asking because if it's had previous burnouts and welding etc, may have a blocked liquid drier or strainer.
Besides that: airflow? pressures and temps at evap, compressor, before TXV etc?

[Reflexive]

I agree,
Blocked liquid line filter, after a burn out replace all the filters, that's been a policy that's worked out well enough for me.

[icemakerman]

yeah ok guys.. thanx for all the suggestions did replace suction burnout drier core did try adjusting tx valve did try replacing liquid line drier also. on investigation found condensor coil to be badly choked with 15 years of build up(unit is located at local aluminium smelter)causing high discharge pressure and also evaporator coil restriction as i said was 100 pa so evaporator is also choked causing unusual low suction and thus appearing like restriction in flowof refrigerant. Have added refrigerant to acheive some subcooling to compressor discharge is at 2000kpa but compressor is not drawing excessive amps so should last till unit replacement,as money has been set aside to replace next year, as i said thanx for the input

[Reflexive]

That choked? Assuming yuo meant the outside of the fins then. Got access to a pressure washer? Blow it down, then to really make sure it'll be okay run some denatured alcohol through it. Be careful, watch out for an ignition source.