Carrier GEMINI 38APD025-100 Operating And Service Manual

Also see for GEMINI SELECT 38APD025: Installation instructions Manual Installation instructions

Carrier GEMINI 38APD025-100 Operating And Service Manual Manual pdf 19 page image

19Table 3 — Thermistor DesignationsTable 4 — Switch InputsCompressor Expansion Module (CXB) — TheCXB is only used on unit sizes 070-100 to provide additionalinputs and outputs for fans and compressors when the unit hasmore than 4 compressors.AUX Board (AUX) — The AUX is used with the digitalscroll option and the low ambient head pressure option. It pro-vides additional inputs and outputs for digital scroll controlalong with analog outputs to control head pressure control fanspeeds.Enable/Off/Remote Contact Switch — The Enable/Off/Remote Contact switch is a 3-position switch used tocontrol the unit. When switched to the Enable position, the unitis under its own control. Move the switch to the Off position toshut the unit down. Move the switch to the Remote Contact po-sition and a field-installed dry contact can be used to start theunit. The contacts must be capable of handling a 24 vac, 50 mAload. In the Enable and Remote Contact (dry contacts closed)positions, the unit is allowed to operate and respond to thescheduling configuration, CCN configuration and set pointdata. See Fig. 21.Emergency On/Off Switch — The Emergency On/Offswitch should only be used when it is required to shut theunit off immediately. Power to the MBB, CXB, AUX, EMM,and scrolling marquee display is interrupted when this switch isoff and all outputs from these modules will be turned off.Board Addresses — The main base board (MBB) has a3-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.Control Module CommunicationRED LED — Proper operation of the control boards can bevisually checked by looking at the red status LEDs(light-emitting diodes). When operating correctly, the red statusLEDs should be blinking in unison at a rate of once every2 seconds. If the red LEDs are not blinking in unison, verifythat correct power is being supplied to all modules. Be sure thatthe main base board (MBB) is supplied with the current soft-ware. If necessary, reload current software. If the problem stillpersists, replace the MBB. A red LED that is lit continuously orblinking at a rate of once per second or faster indicates that theboard should be replaced.GREEN LED — The MBB has one green LED. The LocalEquipment Network (LEN) LED should always be blinkingwhenever power is on. All other boards have a LEN LEDwhich should be blinking whenever power is on. Check LENconnections for potential communication errors at the board J3and/or J4 connectors. Communication between modules isaccomplished by a 3-wire sensor bus. These 3 wires run inparallel from module to module. The J4 connector on the MBBprovides both power and communication directly to themarquee display only.YELLOW LED — The MBB has one yellow LED. TheCarrier Comfort Network (CCN) LED will blink during timesof network communication.THERMISTOR INPUT PIN CONNECTION POINTReturn Air (Accessory) MBB J8-11,12; LVT 19,20Supply Air (Accessory) MBB J8-12,13; LVT 11,19Compressor Return GasTemperature A MBB J8-1,2Compressor Return GasTemperature B MBB J8-3,4Outdoor Air Temperature MBB J8-7,8Discharge Temperature(Digital Option Only) AUX J6-1,2Space Temperature (Accessory) MBB J8-5,6; LVT 21,22SWITCH INPUT PIN CONNECTION POINTThermostat Y1 (Accessory) LVT 12,18Thermostat Y2 (Accessory) LVT 15,18Fan Status 1 (Accessory) LVT 16,18Fan Status 2 (Accessory) LVT 17,18Remote On/Off LVT 13,14High Pressure Switch A MBB J6-4High Pressure Switch B MBB J6-6CEPL130346-01STATUSLENJ1 J2J4 J3J5J6J7 J8 J9J10CCNRED LED - STATUS GREEN LED -LEN (LOCAL EQUIPMENT NETWORK)YELLOW LED -CCN (CARRIER COMFORT NETWORK)INSTANCE JUMPERK11 K10 K9K8 K7 K6 K5K4 K3 K2 K1Fig. 20 — Main Base Board