hubbard ht/lt small pack

[tait71]

hi been working on a new small pack today and could do with some help please, its a ht/lt hubbard pack which runs approx 10 meters of glass door freezer space and 25 meters of arneg multideck chillers, arrived to find all lt compressors off, all compressors covered in ice and all contactors u/s various phases missing, replaced contactors all compressors running ok , setup super heat on freezers which stopped most of the heavy frost checked oil leavel ok, after about 1 hour 1 lt comp went out on low oil, plenty oil in oilsep after 2-3 mins it refilled and restarted it kept doing this for about 1 hour then seemed to right its self but checking oilsep found this low added about 2.5ltrs oil run system all full, 20mins later all comps full of oil but oilsep empty, switched off pack to check stuff on switching on lt comps made horrible noise on start and after 1 min all oil back 20 mins later no oil in sep whats happening?

[coolhibby1875]

you will be getting liquid passing through a valve and lifting the oil, the noise is the compressor starting up against all the liquid, if its got a front end go to it and and see what case has a colder suction probe than the evaporator probe, if you find a case with this check the eev, or its quite possible you have a faulty heat exchanger on a freezer cabinet, if its a co op your in with electrolux cases this is a favorite, and as the heat exchanger is after the suction probe you wont notice it on the front end, those hubbard packs dont like liquid, be carefull not to add too much oil as when you fix the liquid floodback, you will need to take oil back out!!, good luck!!