Step 4 — Make Electrical Connections

WARNING

Before performing service or maintenance operations on unit, turn off main power switch to unit. Electrical shock could cause personal injury.

IMPORTANT: When starting up this equipment for operation, be sure to check tightness of all electrical ter- minal connections, clamps, screws, etc., as they may have become loose during shipment. It is also advisable to re-tighten all electrical connections after equipment has been in operation and components have reacted to operating temperature.

POWER SUPPLY — The electrical characteristics of the available power supply must agree with the unit nameplate rating. Supply voltage must be within the limits shown in Tables 9-12. See Table 13 for incoming power options.

IMPORTANT: Operating unit on improper supply voltage or with excessive phase imbalance constitutes abuse and may adversely affect Carrier warranty.

CAUTION

Proper rotation of condenser fan(s) MUST be verified before compressors are started. Consult the Controls, Start- Up and Operation guide provided with the 38AP units for correct procedure. Failure to comply could result in possi- ble equipment damage.

POWER WIRING — All power wiring must comply with applicable local and national codes. Install field-supplied branch circuit fused disconnect per NEC (National Electrical Code, U.S.A) of a type that can be locked OFF or OPEN. Dis- connect must be within sight and readily accessible from the unit in compliance with NEC Article 440-14.

General Wiring Notes:

1.The control circuit does NOT require a separate power source. Control circuit power is obtained by a step-down transformer from the main three-phase power supply. Be sure that the appropriate connection tap is connected on all transformers for the supply voltage.

2.A low-voltage terminal strip (LVT) is provided for field-wired control devices.

NOTE: The field-supplied disconnect should never be off except 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 in the corner post of the unit or the bottom of the control box shelf. 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 for copper conductors. Insulation must be rated 75 C minimum.

6.Units with high short circuit ratings and terminal block option require that specific fuses be applied to achieve this rating. Refer to Table 13.

CONTROL POWER — Control power is obtained from the main power supply and does NOT require a separate source. A toggle switch (marked Emergency On-Off on the unit label diagram and by the switch) allows the control circuit to be manually disconnected when necessary. Crankcase heaters are in an operable state when this switch is in the Off position. All field control wiring must comply with applicable local and national codes.

IMPORTANT: For 208-v systems, the connection tap for all transformers must be changed. The factory default setting is for 230-v. Failure to connect to the proper tap may result in unreliable operation.

FIELD CONTROL WIRING — The standard unit control is microprocessor based which supports multiple control configurations. 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 unit configuration and desired control requirements.

Constat Volume Application Control Options

1.Two-Stage Thermostat (Part No. 33CS2PP2S-01) — Refer to Fig. 20.

2.Two-Stage Thermostat (Part No. 33CS2PP2S-01) with Multi-Step Control — Refer to Fig. 21. This thermo- stat also requires installation of supply-air temperature sensor and return-air temperature sensor (Part No. 33ZCSENSAT).

3.Space Sensor Control — Refer to Fig. 22. This control also requires installation of supply-air temperature sensor 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, and LCD (liquid crystal display) Display (Part No. 33ZCT59SPT)

Variable Air Volume Application Control Options

1.Discharge-air temperature control requires installation of supply-air temperature sensor and return-air temperature sensor (Part No. 33ZCSENSAT). Refer to Fig. 23.

2.Interface with building automation system may require EMM (energy management module) or translator accessory. Refer to Fig. 23.

Energy Management Module (EMM) Option — The EMM is available for factory or field installation. See Fig. 24 for EMM field wiring.

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Carrier 38APS025-050, 38APD025-100 installation instructions Make Electrical Connections
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38APS025-050, 38APD025-100 specifications

The Carrier 38APD025-100 and 38APS025-050 are advanced air conditioning units designed to optimize comfort and efficiency for residential and commercial spaces. Both models integrate cutting-edge technology with user-friendly features, making them a popular choice among HVAC professionals and homeowners alike.

The Carrier 38APD025-100 is a 2-ton air conditioning unit that boasts a Seasonal Energy Efficiency Ratio (SEER) rating of 16. This high SEER rating indicates energy savings and lower operating costs, an essential factor for environmentally conscious consumers. Its compact design allows for easy installation in various spaces, while the durable construction ensures longevity and reliability.

On the other hand, the Carrier 38APS025-050 is a 2.5-ton model known for its efficient cooling capabilities and versatile features. With a SEER rating that reaches up to 17, this model also emphasizes energy conservation without sacrificing performance. The 38APS025-050 is particularly suited for larger spaces or applications requiring more cooling capacity.

Both units incorporate Carrier's innovative technology, including the Inverter Compressor System. This technology adjusts the compressor's speed based on the required cooling demand, leading to quieter operation and reduced energy consumption. Additionally, both models feature two-stage cooling to enhance comfort and humidity control, ensuring a consistent indoor climate.

The units are equipped with advanced filtration systems that improve indoor air quality by capturing dust, pollen, and other airborne particles. This is particularly beneficial for allergy sufferers, as it helps to create a healthier living environment.

Another key characteristic of these models is their compatibility with smart thermostats and home automation systems. Users can control their air conditioning units remotely, setting schedules, adjusting temperatures, and monitoring energy usage via mobile apps. This smart technology not only enhances convenience but also contributes to energy savings.

In summary, the Carrier 38APD025-100 and 38APS025-050 stand out in the market for their impressive efficiency, advanced technology, and user-friendly features. They represent a blend of performance and comfort, making them an ideal choice for anyone looking to invest in a reliable and energy-efficient air conditioning solution. Whether for a home or a commercial application, these models deliver quality and value.
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