Carrier GEMINI SELECT 38APD025-100 Installation Instructions Manual

Also see for GEMINI SELECT 38APD025: Installation instructions Manual Operating and service guide

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Carrier GEMINI SELECT 38APD025-100 Installation Instructions Manual Manual pdf 26 page image

26Step 4 — Make Electrical ConnectionsPOWER SUPPLY — The electrical characteristics of theavailable power supply must agree with the unit nameplaterating. Supply voltage must be within the limits shown inTables 9-12. See Table 13 for incoming power options.POWER WIRING — All power wiring must comply withapplicable local and national codes. Install field-suppliedbranch circuit fused disconnect per NEC (National ElectricalCode, U.S.A) of a type that can be locked OFF or OPEN. Dis-connect must be within sight and readily accessible from theunit in compliance with NEC Article 440-14.General Wiring Notes:1. The control circuit does NOT require a separate powersource. Control circuit power is obtained by a step-downtransformer from the main three-phase power supply. Besure that the appropriate connection tap is connected onall transformers for the supply voltage.2. A low-voltage terminal strip (LVT) is provided forfield-wired control devices.NOTE: The field-supplied disconnect should never be offexcept when unit is being serviced or is to be down for a pro-longed period.3. Power entry is at one end only.4. All field power enters the unit through a hole located inthe corner post of the unit or the bottom of the control boxshelf. Refer to Fig. 18 for field power wiring details. Re-fer to Fig. 5-8 for exact location of field power entry.5. Terminals for field power supply are suitable only forcopper conductors. Insulation must be rated 75 Cminimum.6. Units with high short circuit ratings and terminal blockoption require that specific fuses be applied to achievethis rating. Refer to Table 13.CONTROL POWER — Control power is obtained from themain power supply and does NOT require a separate source. Atoggle switch (marked Emergency On-Off on the unit labeldiagram and by the switch) allows the control circuit to bemanually disconnected when necessary. Crankcase heaters arein an operable state when this switch is in the Off position. Allfield control wiring must comply with applicable local andnational codes.FIELD CONTROL WIRING — The standard unit control ismicroprocessor based which supports multiple controlconfigurations. See Fig. 19 for EAT (evaporator air tempera-ture sensor) and SAT (supply air temperature sensor) layout.Figures 20-24 show specific field wiring, depending on unitconfiguration and desired control requirements.Constat Volume Application Control Options1. Two-Stage Thermostat (Part No. 33CS2PP2S-01) —Refer to Fig. 20.2. Two-Stage Thermostat (Part No. 33CS2PP2S-01) withMulti-Step Control — Refer to Fig. 21. This thermo-stat also requires installation of supply-air temperaturesensor and return-air temperature sensor (Part No.33ZCSENSAT).3. Space Sensor Control — Refer to Fig. 22. This controlalso requires installation of supply-air temperaturesensor and return-air temperature sensor (Part No.33ZCSENSAT).a. Space Temperature Sensor with Occupancy Over-ride Button (Part No. 33ZCT55SPT)b. Space Temperature Sensor with Occupancy Over-ride Button and Set Point Adjustment Slidebar(Part No. 33ZCT56SPT)c. Space Temperature Sensor with Occupancy Over-ride Button, Set Point Adjustment Slidebar, andLCD (liquid crystal display) Display (Part No.33ZCT59SPT)Variable Air Volume Application Control Options1. Discharge-air temperature control requires installationof supply-air temperature sensor and return-airtemperature sensor (Part No. 33ZCSENSAT). Refer toFig. 23.2. Interface with building automation system may requireEMM (energy management module) or translatoraccessory. Refer to Fig. 23.Energy Management Module (EMM) Option — The EMMis available for factory or field installation. See Fig. 24 forEMM field wiring.WARNINGBefore performing service or maintenance operations onunit, turn off main power switch to unit. Electrical shockcould cause personal injury.IMPORTANT: When starting up this equipment foroperation, be sure to check tightness of all electrical ter-minal connections, clamps, screws, etc., as they mayhave become loose during shipment. It is also advisableto re-tighten all electrical connections after equipmenthas been in operation and components have reacted tooperating temperature.IMPORTANT: Operating unit on improper supplyvoltage or with excessive phase imbalance constitutesabuse and may adversely affect Carrier warranty.CAUTIONProper rotation of condenser fan(s) MUST be verifiedbefore compressors are started. Consult the Controls, Start-Up and Operation guide provided with the 38AP units forcorrect procedure. Failure to comply could result in possi-ble equipment damage.IMPORTANT: For 208-v systems, the connection tapfor all transformers must be changed. The factorydefault setting is for 230-v. Failure to connect to theproper tap may result in unreliable operation.