Daikin DCH048 Series Service Instructions Manual

Also see for DCC048 SERIES: Installation instructions

Daikin DCH048 Series Service Instructions Manual Manual pdf 27 page image

SERVICING27C L G N1 2 3 4 5High VoltageConnections3/16"Low Voltage Connections1/4”EEM MOTOR CONNECTIONSS-17 CHECKING COMPRESSOR WINDINGSWARNINGHermetic compressor electrical terminal venting canbe dangerous. When insulating material whichsupports a hermetic compressor or electrical terminalsuddenly disintegrates due to physical abuse or as aresult of an electrical short between the terminal andthe compressor housing, the terminal may beexpelled, venting the vapor and liquid contents of thecompressor housing and system.If the compressor terminal PROTECTIVE COVER andgasket (if required) are not properly in place and se-cured, there is a remote possibility if a terminal vents, thatthe vaporous and liquid discharge can be ignited, spout-ing flames several feet, causing potentially severe or fatalinjury to anyone in its path.This discharge can be ignited external to the compressorif the terminal cover is not properly in place and if thedischarge impinges on a sufficient heat source.Ignition of the discharge can also occur at the ventingterminal or inside the compressor, if there is sufficientcontaminant air present in the system and an electricalarc occurs as the terminal vents.Ignition cannot occur at the venting terminal without thepresence of contaminant air, and cannot occur externallyfrom the venting terminal without the presence of anexternal ignition source.Therefore, proper evacuation of a hermetic system isessential at the time of manufacture and during servicing.To reduce the possibility of external ignition, all openflame, electrical power, and other heat sources should beextinguished or turned off prior to servicing a system.S-17A RESISTANCE TESTEach compressor is equipped with an internal overload.The line break internal overload senses both motor amperageand winding temperature. High motor temperature or amper-age heats the disc causing it to open, breaking the commoncircuit within the compressor on single phase units.Heat generated within the compressor shell, usually due torecycling of the motor, high amperage or insufficient gas tocool the motor, is slow to dissipate. Allow at least three to fourhours for it to cool and reset, then retest.HIGH VOLTAGE!Disconnect ALL power before servicingor installing this unit. Multiple powersources may be present. Failure to do somay cause property damage, personal injuryor death.1. Remove the leads from the compressor terminals.See warnings S-17 before removing compressorterminal cover.2. Using an ohmmeter, test continuity between terminals S-R, C-R, and C-S, on single phase units or terminals T1,T2 and T3, on 3 phase units.S RCCOMPOHMMETERTESTING COMPRESSOR WINDINGSIf either winding does not test continuous, replace thecompressor.NOTE: If an open compressor is indicated, allow ample timefor the internal overload to reset before replacing compres-sor.S-17B GROUND TESTIf fuse, circuit breaker, ground fault protective device, etc.,has tripped, this is a strong indication that an electricalproblem exists and must be found and corrected. The circuitprotective device rating must be checked, and its maximumrating should coincide with that marked on the equipmentnameplate.