Carrier 25HPA6 instruction manual Compressor Crankcase Heater, Airflow Selections ECM Furnaces

25HPA6

NOTE: Operation of unit on improper line voltage constitutes abuse and could affect unit reliability. See unit rating plate. Do not install unit in system where voltage may fluctuate above or below permissible limits.

NOTE: Use copper wire only between disconnect switch and unit.

NOTE: Install branch circuit disconnect of adequate size per NEC to handle unit starting current. Locate disconnect within sight from and readily accessible from unit, per Section 440-14 of NEC.

Route Ground and Power Wires

Remove access panel to gain access to unit wiring. Extend wires from disconnect through power wiring hole provided and into unit control box.

!WARNING

ELECTRICAL SHOCK HAZARD

Failure to follow this warning could result in personal injury or death.

The unit cabinet must have an uninterrupted or unbroken ground to minimize personal injury if an electrical fault should occur. The ground may consist of electrical wire or metal conduit when installed in accordance with existing electrical codes.

Connect Ground and Power Wires

Connect ground wire to ground connection in control box for safety. Connect power wiring to contactor as shown in Fig. 5.

DISCONNECT

PER N. E. C. AND/OR

LOCAL CODES

Compressor Crankcase Heater

Furnish power to crankcase heater a minimum of 24 hr before starting unit. To furnish power to heater only, set thermostat to OFF and close electrical disconnect to outdoor unit.

Airflow Selections (ECM Furnaces)

The ECM Furnaces provide blower operation to match the capacities of the compressor during high and low stage cooling operation. Tap selections on the furnace control board enable the installing technician to select the proper airflows for each stage of cooling. Below is a brief summary of the furnace airflow configurations

1.The Y2 call for high stage cooling energizes the “Cool” tap on the control board. The grey wire from cool tap is connec- ted to tap 5 on the motor. Refer to the furnace Product Data to find the corresponding airflow. If the airflow setting for high cooling needs to be switched from tap 5 to a different tap, jumper a connection from the cool tap to the desired tap so that the Y2 signal is communicated via the cool tap to the desired speed tap.

2.The Y1 call for low stage cooling energizes the “Fan” tap on the control board. The red wire from the fan tap is con- nected to tap 1 on the motor. Refer to the furnace Product Data to find the corresponding airflow. If the airflow setting for low cooling needs to be switched from tap 1 to a differ- ent tap, jumper a connection from the Fan tap to the desired tap so that the Y1 signal is communicated via the Fan tap to the desired speed tap. The Y1 setting will also govern the continuous fan airflow for the furnace.

Refer to the furnace literature for further details.

Airflow Selection for Variable Speed Furnaces (non-communicating)

FIELD POWER

WIRING

FIELD GROUND

WIRING

CONTACTOR

GROUND

LUG

A91056

The variable speed furnaces provide blower operation to match the capacities of the compressor during high and low stage cooling operation. The furnace control board allows the installing technician to select the proper airflows for each stage of cooling. Below is a summary of required adjustments. See furnace installation instructions for more details:

1.	Turn SW1--5 ON for 400 CFM/ton airflow or OFF for 350
	CFM/ton airflow. Factory default is OFF.
2.	The A/C DIP switch setting determines airflow during high
	stage cooling operation. Select the A/C DIP switch setting

Fig. 5 - Line Power Connections

Connect Control Wiring

Route low voltage control wires through control wiring grommet and connect leads to control board.

Connect to Infinity connections ABCD only when Infinity User Interface is available.

Standard non-communicating thermostat connections are possible when you connect to standard thermostat connections R, C, W, Y1, Y2, and O. Refer to wiring label for further clarification.

General Information

Use No. 18 AWG color-coded, insulated (35°C minimum) wire for all installations.

All wiring must be NEC Class 1 and must be separated from incoming power leads.

Use furnace transformer, fan coil transformer, or accessory transformer for control power, 24v/40va minimum. The outdoor unit requires a minimum of 27va/24vac control power.

Final Wiring Check

IMPORTANT: Check factory wiring and field wire connections to ensure terminations are secured properly. Check wire routing to ensure wires are not in contact with tubing, sheet metal, etc.

corresponding to the available airflow shown in the furnace

Installation Instructions that most closely matches the re-

quired airflow shown in the air conditioning Product Data

for HIGH speed.

3. The CF DIP switch setting determines airflow during low

stage cooling operation. Select the CF DIP switch setting

corresponding to the available airflow shown in the furnace

installation instructions that most closely matches the re-

quired airflow shown in the air conditioning Product Data

for LOW speed. If a higher or lower continuous fan speed is

desired, the continuous fan speed can be changed using the

fan switch on the thermostat. Refer to the furnace Installa-

tion Instructions for details of how to use this feature.

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