Daikin AGZ 025D Operating & Maintenance Manual

Daikin AGZ 025D Operating & Maintenance Manual Manual pdf 78 page image

78 AGZ 025D through 190D OMM 1166-1The filter-drier should also be changed if themoisture indicating liquid line sight glassindicates excess moisture in the system.During the first few months of operation thefilter-drier replacement can be necessary if thepressure drop across the filter-drier exceeds thevalues listed in the paragraph above. Anyresidual particles from the condenser tubing,compressor and miscellaneous components areswept by the refrigerant into the liquid line andare caught by the filter-drier.BatteryThe microprocessor has a battery locatedbehind the clear plastic bezel. It is a BR2032with a minimum life of 2 years unpowered. Itwould be prudent to replace it on a 2-yearcycle. There is no indication of an eminentfailure.Liquid Line Solenoid ValveThe liquid line solenoid valves that shut offrefrigerant flow in the event of a power failuredo not normally require any maintenance. Thesolenoids can, however, require replacement ofthe solenoid coil or of the entire valveassembly.The solenoid coil can be checked to see thatthe stem is magnetized when energized bytouching a screwdriver to the top of the stem.If there is no magnetization, either the coil isbad or there is no power to the coil.The solenoid coil can be removed from thevalve body without opening the refrigerantpiping after pumpdown. For personal safety,shut off and lock out the unit power.The coil can then be removed from the valvebody by simply removing a nut or snap-ringlocated at the top of the coil. The coil can thenbe slipped off its mounting stud forreplacement.To replace the entire solenoid valve follow thesteps involved when changing a filter-drier.EvaporatorThe evaporators on AGZ-C models 030 - 130 arebrazed plate type, and on models 140, 160, and180 they are shell-and-tube type. Other thancleaning and testing, no service work should berequired on the evaporator.