Hydrocarbons.

[suctionheader]

I have been to a few jobs recently involving hydrocarbons [R290 R1270] in multi deck chiller intregals in supermarkets. Cabinets have been only reaching 6 degrees, checked suction pressures which were 1 - 2 bar above normal operating pressures. Cleaned condensers, no difference made. Went down the road of removing refrigerant, purging system with nitrogen, replacing drier, vacuuming out and recharging system. This fixed the problem. My own theory to why these faults occur is that the refrigerant is affected when high head pressures occur when the condenser is choked or a condenser fan motor fails. Has anybody got any other ideals ?

[Brian_UK]

Did you recover the correct system charge?

[Tayters]

Well I've heard that the AHT chest freezers in Lidl's can pack up - pressures all ship shape and a change of refrigerant cures all - as recommended from AHT, bit sceptical but it worked so can't argue. These use R404A.

Cheers,
Andy

[suctionheader]

Did you recover the correct system charge?
Recovered correct charge.