Carrier AquaSnap 30MPA Series Controls, Start-up, Operation, Service, And Troubleshooting

Also see for AQUASNAP 30MPA: User manual Operation and service manual Installation instructions

Carrier AquaSnap 30MPA Series Controls, Start-up, Operation, Service, And Troubleshooting Manual pdf 18 page image

18represents the amount of time to elapse before the unit will startits initialization routine. This value can be zero without themachine running in many situations. These can include beingunoccupied, ENABLE/OFF/REMOTE CONTROL switch inthe OFF position, CCN not allowing unit to start, DemandLimit in effect, no call for cooling due to no load, and alarm oralert conditions present. If the machine should be running andnone of the above are true, a minimum off time (DELY, seebelow) may be in effect. The machine should start normallyonce the time limit has expired.MINUTES OFF TIME — The Minutes Off Time feature(ConfigurationOPT2DELY) is a user-configurable timeperiod used by the control to determine how long unit opera-tion is delayed after the unit has been enabled. This delay isinitiated following the Enable-Off-Remote Switch beingplaced in “Enable” position or “Remote” with remote contactsclosed, or if power is applied/restored to the unit with the En-able-Off-Remote Switch in a position that would allow the unitto operate. Typically, this time period is configured when mul-tiple machines are located on a single site. For example, thisgives the user the ability to prevent all the units from restartingat once after a power failure. A value of zero for this variabledoes not mean that the unit should be running.If Minutes Off Time is active, the control will indicate Op-erating Mode, Minutes Off Time Active (OperatingModesMODEMD10 will indicate YES).CAPACITY CONTROL OVERRIDES — The followingoverrides will modify the normal operation of the routine.Deadband Multiplier — The user configurable DeadbandMultiplier (ConfigurationSLCTZ.GN) has a defaultvalue of 1.0. The range is from 1.0 to 4.0. When set to otherthan 1.0, this factor is applied to the capacity Load/UnloadFactor. The larger this value is set, the longer the control willdelay between adding or removing stages of capacity. Figure14 shows how compressor starts can be reduced over time ifthe leaving water temperature is allowed to drift a largeramount above and below the set point. This value should be setin the range of 3.0 to 4.0 for systems with small loop volumes.First Stage Override — If the current capacity stage is zero,the control will modify the routine with a 1.2 factor on addingthe first stage to reduce cycling. This factor is also appliedwhen the control is attempting to remove the last stage ofcapacity.Slow Change Override — The control prevents the capacitystages from being changed when the leaving fluid temperatureis close to the set point (within an adjustable deadband) andmoving towards the set point.CEBD430351-0396-01CTEST 1CEPL130351-01PWRTEST 2J1 J2J4 J3J5J6J7LENSTATUSRED LED - STATUS GREEN LED -LEN (LOCAL EQUIPMENT NETWORK) ADDRESSDIP SWITCHFig. 13 — Energy Management Module