If you have read your meter’s manual you have most certainly come across it’s “correction calculation”, usually in the back of the manual. But Isobutane is not a common flammable, so why did it make it on the list of those popular flammables? It is because of the “green movement”… yes, Isobutane (R-600a) is a popular refrigerant for small appliances. In terms of ASHRAE 34a listing, it is an A3 Refrigerant… meaning it carries the highest flammability rating, but a lesser toxicity rating, of refrigerants (as shown below)
Service Procedures
Pre-service Safety Check
- Check the data plate or label on the compressor to determine which refrigerant is used. Look for the presence of red color process tubing.
- Use a combustible gas leak detector to perform a background check around the appliance. CAUTION: To avoid a risk of injury, do NOT use leak detectors with an arc or spark module to check for leaks in and around appliances that use A2L or A3 refrigerants. Technicians must be trained in the use, and the device must be certified for use with the specific refrigerant class being serviced. If flammable refrigerant is detected, immediately ventilate the room, evacuate the area, and notify the owner or customer. Recheck with a combustible gas leak detector before proceeding.