Suction Line in Vacuum.

[pen_ster2002]

I am going out to a breakdown of a 3.5Kw Fujitsu R-410 this afternoon. I am sorry I don't have the model of the unit. Someone has taken a look and has told me the suction line is in vacuum. Aparently when he removed the cap from the L.P service valve it proceeded to suck in air. I mostly do installs so am lacking alot of the fault finding skills. This is a favour for a mate. Would I be right in thinking this may be a blockage, filter drier etc. Or is it more likely to be a compressor. I asked the person who looked first time if their was any faults shown on the unit wich there wasn't. Also asked him to check if both service valves were fully open, he said they were. Any help would be most appericiated.

Thanks.

[nike123]

First clean indoor and outdoor unit and filters.
Recover refrigerant , vacuum unit to 500 microns for at least 20 min (at that vacuum level or lower), check for vacuum pressure rise

and, if everything is OK, weigh in new refrigerant.
Then after 20 min. of work, check pressures and temperatures again.
If then you have vacuum at port, check for frosting at pipes, capilary assembly etc...!

[M.Amer]

MR pen check T.X.V. los of thermal bulb charge check out the setting of your system low pressure switch .

[nike123]

MR pen check T.X.V. los of thermal bulb charge check out the setting of your system low pressure switch .

There is no TXV at Fujitsu 3,5KW!

[multisync]

There is no TXV at Fujitsu 3,5KW!

I doubt a LP switch either!!

[pen_ster2002]

Sorry for the late reply. Went out to have a look on friday. When I got there unit had no charge in it at all. When I took the cap of the service valve it did suck in air. Valve looked a bit knackered. Soon as I added nitrogen could hear hiss somewhere around the compressor. Opened up the casing to find a cooked comp. The lagging around it had got that hot it had charred and completely broken down. Bad location for unit in the first place, business unit that backs onto working farm. The unit is in with cow sheds just above their feeding troughs. Condenser was completly blocked. hired them a couple of mobiles untill they decide whether to let my install new unit.

[bangoman]

I think the compressor was cooked because of runnin in vacuum.Think u have to check for blockages along the system.