Lennox LB - 110135A, Loss of Charge Kit The loss of charge kit (LB - 110135A / 84M23) is used with all condensing units and heat pumps which use either R - 22 or R - 410A refrigerant. The loss of charge switch protects the system compressor from damage due to a loss of charge. The single - pole / single - throw, normally closed switch is permanently adjusted to open at 25 psig (+5 psig). The switch automatically resets (closes) at 55 psig (+5 psig). Includes: Loss of charge switch (100216-01) Valve depressor tee fitting (LB-53109D) (2) - Wire nuts