Carrier WEATHERMASTER 48/50Z030-105 Operation And Service Manual

Also see for 48/50Z030-105: Installation instructions

Contents

Carrier WEATHERMASTER 48/50Z030-105 Operation And Service Manual Manual pdf 42 page image

42HVAC Mode — VENT (09) — This is a normal operationmode where no heating or cooling is required and outside air isbeing delivered to the space to control IAQ levels.HVAC Mode — HIGH COOL (10) — This is a normal cool-ing mode where a high cooling demand is required.HVAC Mode — LOW COOL (11) — This is a normal cool-ing mode where a low cooling demand is required.HVAC Mode — UNOCC. FREE COOL (12) — In thismode the unit will operate in cooling but will be using theeconomizer for free cooling. Entering this mode will depend onthe status of the outside air. The unit can be configured for out-side air changeover, differential dry bulb changeover, outsideair enthalpy changeover, differential enthalpy changeover, or acustom arrangement of enthalpy/dewpoint and dry bulb. Seethe Economizer section for further details.HVAC Mode — TEMPERING HICOOL (13) — The econ-omizer is at minimum vent position but the combination of theoutside-air temperature and the economizer position hasdropped the supply-air temperature below the tempering coolset point. Staged gas heat or hydronic heat is used to temper theventilation air.HVAC Mode — TEMPERING LOCOOL (14) — The econ-omizer is at minimum vent position but the combination of theoutside-air temperature and the economizer position hasdropped the supply-air temperature below the tempering coolset point. Staged gas heat or hydronic heat is used to temper theventilation air.HVAC Mode — TEMPERING VENT (15) — The econo-mizer is at minimum vent position but the supply-air tempera-ture has dropped below the tempering vent set point. Stagedgas heat or hydronic heat is used to temper the ventilation air.HVAC Mode — LOW HEAT (16) — The unit will be in lowheating demand mode using either gas or electric heat.HVAC Mode — HIGH HEAT (17) — The unit will be inhigh heating demand mode using either gas or electric heat.HVAC Mode — FREEZESTAT TRIP (18) — If the Freez-estat trips, the unit enters the Freezestat Trip HVAC mode. Thesupply fan will run, the hydronic heat valve will be wide open,and the economizer damper will be at minimum.HVAC Mode — STATIC PRESSURE FAIL (19) — Theunit is off due to failure of the static pressure sensor.HVAC Mode — PLENUM PRESSURE FAIL (20) — Theunit is off due to a plenum pressure switch trip.HVAC Mode — FIRE SHUT DOWN (21) — The unit hasbeen stopped due to a fire shutdown input (FSD) or two ormore of the fire control modes, purge, evacuation, or pressur-ization have been requested simultaneously.HVAC Mode — PRESSURIZATION (22) — The unit is inthe special fire pressurization mode where the supply fan is on,the economizer damper is open and the power exhaust fans areoff. This mode is invoked by the Fire Pressurization (PRES)input which can be found in the INPUT→FIRE submenu.HVAC Mode — EVACUATION (23) — The unit is in thespecial Fire Evacuation mode where the supply fan is off, theeconomizer damper is closed and the power exhaust fans areon. This mode is invoked by the Fire Evacuation (EVAC) inputwhich can be found in the INPUT→FIRE submenu.HVAC Mode — SMOKE PURGE (24) — The unit is in thespecial Fire Purge mode where the supply fan is on, the econo-mizer damper is open and the power exhaust fans are on. Thismode is invoked by the Fire Evacuation (PURG) input whichcan be found in the INPUT→FIRE submenu.HVAC Mode — DEHUMIDIFICATION (25) — The unit isoperating in the Dehumidification mode.HVAC Mode — RE-HEAT (26) — The unit is operating inReheat mode.Unit Configuration Submenu — The UNIT sub-menu under the Configuration mode of the local displaycontains general unit configuration items. This section willdefine all of these configurations here for easy reference. Thesub-menu which contains these configurations is located at thelocal display under Configuration→UNIT. See Table 33.Machine Control Type (C.TYP) — This configuration de-fines the technique and control source responsible for selectinga cooling, heating, or vent mode and in determining the methodby which compressors are staged. The control types are:• C.TYP = 1 (VAV-RAT) and C.TYP = 2 (VAV-SPT)Both of these configurations refer to standard VAV opera-tion. If the control is occupied, the supply fan is runcontinuously and return-air temperature will be used in thedetermination of the selection of a cooling mode. VAV-SPTdiffers from VAV-RAT only in that during the unoccupiedperiod, space temperature will be used instead of return-airtemperature to start the fan for 10 minutes to establish anaccurate return-air temperature before the return-air temper-ature is allowed to call out any mode.• C.TYP = 3 (TSTAT – MULTI)This configuration will force the control to monitor the ther-mostat inputs to make a determination of mode. Unliketraditional 2-stage thermostat control, the unit is allowed touse multiple stages of cooling control and perform VAV-type operation. The control will be able to call out a LOWCOOL or a HIGH COOL mode and maintain a low or highcool supply air set point.• C.TYP = 4 (TSTAT- 2 STG)This configuration will force the control to monitor the ther-mostat inputs to make a determination of mode and allowonly 2 stages of control for both heating and cooling.• C.TYP = 5 (SPT – MULTI)This configuration will force the control to monitor a spacetemperature sensor to make a determination of mode.Unlike traditional 2-stage space temperature control, theunit is allowed to use multiple stages of cooling control andperform VAV-type operation. The control will be able to callout a LOW COOL or a HIGH COOL mode and maintain alow or high cool supply air set point.• C.TYP = 6 (SPT- 2 STG)This configuration will force the control to monitor thespace temperature sensor to make a determination of modeand allow 2 stages of control for both heating and cooling.