Carrier 50VT Manual: Essential Guide for Installation and Operation

4.Remove the vinyl cap off of the desired speed tap wire (Refer to Table 3 for color coding) for the normal cooling fan speed and place desired speed tap wire on “HIGH” on the interface board.

5.Refer to airflow tables (Table 4) to determine allowable speeds for the dehumidification cooling fan speed. In Table 4, speeds that are not allowed for dehumidification cooling are shaded.

6.Remove the vinyl cap off of the desired speed tap wire (Refer to Table 3 for color coding) for the dehumidification cooling fan speed and place desired speed tap wire on the “LOW” connection on the interface board (IFB). Verify that static pressure is in the acceptable range for the speed tap to be used for dehumidification cooling.

7.Use any spare vinyl plugs to cap any unused speed tap wires.

Single Speed Cooling With Higher Electric Heat Speed

This unit can also be configured to operate with single speed cooling and a higher speed for an accessory electric heater.

1.Move the two pin DEHUM jumper located on control board (see Fig. 16) from the “STD” position to the “DEHUM” position.

2.See Table 2 for minimum airflow for electric heat operation. Add electric heater and filter pressure drop to duct system static pressure to determine total external static pressure.

3.Select speed tap from Table 4 that will achieve required airflow from Table 2.

4.Remove the vinyl cap off of the desired speed tap wire (Refer to Table 3 for color coding).

5.Connect the desired speed tap wire to the “HIGH” terminal on the interface fan board (IFB).

!CAUTION

UNIT OPERATION HAZARD

Failure to follow this caution may result in unit component damage or improper operation.

To use this mode, a speed connection must be made on the “HIGH” terminal that meets or exceeds the minimum airflow found in Table 2.

Table 3 – Color Coding for Indoor Fan Motor Leads

Black = High Speed

Orange = Med--High Speed

Red = Med Speed

Pink = Med--Low Speed

Blue = Low Speed

!WARNING

ELECTRICAL SHOCK HAZARD

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

Disconnect electrical power to the unit and install lockout tag before changing blower speed.

Continuous Fan Operation

When the DEHUM feature is not used, the continuous fan speed will be the same as cooling fan speed. When the DEHUM feature is used, the continuous fan will operate on IFB “LOW” speed when the DH control lead is not energized, or IFB “HIGH” speed when the DH lead is energized (see Fig. 16).

50VT-- A

ACCUMULATOR COMPRESSOR

HP S

OUTDOOR COIL INDOOR COIL

TXV in Metering

Position

LCS

LEGEND	Bypass
	Position

HPS – High Pressure Switch

LCS – Loss of Charge Switch

Accurater®Metering De vice

Arrow indicates direction of flow

C03011

Fig. 15 - Typical Heat Pump Operation, Cooling Mode

19