Carrier Air Conditioner Operation And Service Manual

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3Table 1A — Unit Sizes and Modular Combinations(30GTN,R)*60 Hz units/50 Hz units.Table 1B — Unit Sizes and Modular Combinations(30GUN,R)*60 Hz units/50 Hz units.MAJOR SYSTEM COMPONENTSGeneral — The 30GTN,R and 30GUN,R air-cooled recip-rocating chillers contain the ComfortLink™ electronic controlsystem that controls and monitors all operations of the chiller.The control system is composed of several components aslisted in the sections below. See Fig. 1 for typical control boxdrawing. See Fig. 2-4 for control schematics.Main Base Board (MBB) — See Fig. 5. The MBB isthe heart of the ComfortLink control system. It contains themajor portion of operating software and controls the operationof the machine. The MBB continuously monitors input/outputchannel information received from its inputs and from all othermodules. The MBB receives inputs from thermistors T1-T6,T9, and T10. See Table 2. The MBB also receives the feedbackinputs from compressors A1, A2, B1 and B2, and other statusswitches. See Table 3. The MBB also controls several outputs.Relay outputs controlled by the MBB are shown in Table 4.Information is transmitted between modules via a 3-wire com-munication bus or LEN (Local Equipment Network). TheCCN (Carrier Comfort Network) bus is also supported. Con-nections to both LEN and CCN buses are made at TB3. SeeFig. 5.Expansion Valve (EXV) Board — The electronic ex-pansion valve (EXV) board receives inputs from thermistorsT7 and T8. See Table 2. The EXV board communicates withthe MBB and directly controls the expansion valves to main-tain the correct compressor superheat.Compressor Expansion Board (CXB) — TheCXB is included as standard on sizes 150-210 (60 Hz) and 130(50 Hz) and associated modular units. The compressor expan-sion board (CXB) receives the feedback inputs from compres-sors A3, B3 and A4. See Table 3. The CXB board communi-cates the status to the MBB and controls the outputs for thesecompressors. An additional CXB is required for unit sizes 040-110, 130 (60 Hz), 230B-315B with additional unloaders.Scrolling Marquee Display — This device is the key-pad interface used for accessing chiller information, readingsensor values, and testing the chiller. The marquee display is a4-key, 4-character, 16-segment LED (light-emitting diode) dis-play. Eleven mode LEDs are located on the display as well asan Alarm Status LED. See Marquee Display Usage section onpage 29 for further details.Energy Management Module (EMM) — TheEMM module is available as a factory-installed option or as afield-installed accessory. The EMM module receives 4 to20 mA inputs for the temperature reset, cooling set point resetand demand limit functions. The EMM module also receivesthe switch inputs for the field-installed 2-stage demand limitand ice done functions. The EMM module communicates thestatus of all inputs with the MBB, and the MBB adjusts thecontrol point, capacity limit, and other functions according tothe inputs received.Enable/Off/Remote Contact Switch — TheEnable/Off/Remote Contact switch is a 3-position switch usedto control the chiller. When switched to the Enable position thechiller is under its own control. Move the switch to the Off po-sition to shut the chiller down. Move the switch to the RemoteContact position and a field installed dry contact can be used tostart the chiller. The contacts must be rated for dry circuit appli-cation capable of handling a 24 vac load. In the Enable and Re-mote Contact (dry contacts closed) positions, the chiller is al-lowed to operate and respond to the scheduling configuration,CCN configuration and set point data. See Fig. 6.Emergency On/Off Switch — The Emergency On/Off switch should only be used when it is required to shut thechiller off immediately. Power to the MBB, EMM, CXB, andmarquee display is interrupted when this switch is off and alloutputs from these modules will be turned off. The EXV boardis powered separately, but expansion valves will be closed as aresult of the loss of communication with the MBB. There is nopumpout cycle when this switch is used. See Fig. 6.Reset Button — A reset button is located on the fuse/circuit breaker panel for unit sizes 130-210 and associatedmodules. The reset button must be pressed to reset eitherCircuit Ground Fault board in the event of a trip.Board Addresses — The Main Base Board (MBB) hasa 3-position Instance jumper that must be set to ‘1.’ All otherboards have 4-position DIP switches. All switches are set to‘On’ for all boards.UNIT30GTN,RNOMINALTONSSECTION AUNIT 30GTN,RSECTION BUNIT 30GTN,R040 40 — —045 45 — —050 50 — —060 60 — —070 70 — —080 80 — —090 90 — —100 100 — —110 110 — —130 125 — —150 145 — —170 160 — —190 180 — —210 200 — —230 220 150 080245 230 150 090255 240 150 100270 260 170 100290 280 190 110315 300 210 110330 325 170 170360 350 190 190/170*390 380 210 190420 400 210 210UNIT30GUN,RNOMINALTONSSECTION AUNIT 30GUN,RSECTION BUNIT 30GUN,R040 26 — —045 28 — —050 34 — —060 42 — —070 48 — —080 55 — —090 59 — —100 66 — —110 72 — —130 84 — —150 99 — —170 110 — —190 122 — —210 134 — —230 154 150 080245 158 150 090255 165 150 100270 176 170 100290 193 190 110315 206 210 110330 219 170 170360 243 190 190/170*390 256 210 190420 268 210 210