Refrigerant Leak Testing
Because HCFC-22 and HFC-1 34a are above atmospher ic pr e ssure at room temperat ure,
leak testing can be perf or m ed with refrigerant in the m ac h ine. Use an electronic, hal ide leak
detector, soap bubble s ol ution, or ultra-soni c leak detector. Be sure tha t the room is well
ventilated and free fro m concentration of ref r ige rant to keep false readi ngs t o a minimum.
Before making any necess a ry repairs to a leak, tran sfer all refrigerant fr om th e leaking vessel.
Leak Rate
ASHRAE recommends that machines should be immed iately taken off line and r epa ired if
the refrigerant lea kage rate for th e entire machine is more than 10% of the op erating refrigera nt
charge per year. Addit ion ally, Carrier recom m end s that leaks totalling le s s tha n the above rate
but more than a rate of 1 lb (0.5 kg) per year should be repaired during annual maintenanc e or
whenever the refrigera nt is pumped over for other s er v i ce work.
Test After Service, Repair, or Major Leak
If all refrigerant has been lo st or if the machine has been open ed for service, the machine or
the affected vessels must be pressured and leak tes ted. Refer to the Leak Test Machine section
to perform a leak test.