Carrier 50BV020-064 a50-7273ef, Recommended Cables, a50-7164tf, Field Terminal Block

FIELD-SUPPLIED THERMOSTAT

C O Y1 Y2 R G

	UNIT MODULE ‘A’
C	O Y1 Y3 R	G

PR1

PR2

UNIT MODULE ‘B’

C O Y2 Y4 R G

LEGEND

FC — Fan Contactor

PR — Pilot Relay

PR2

PR1

a50-7273ef

Remote Condenser Units Only

(#1)	FC1-4	FC1-5
		PR1
(#2)	FC1-4	FC1-5
		PR2

Fig. 25 — Typical Wiring 40 to 60 Ton Units (Two-Stage Cooling)

Table 10 — Recommended Cables

MANUFACTURER	PART NUMBER
Alpha	2413 or 5463
American	A22503
Belden	8772
Columbia	02525

NOTE: Conductors and drain wire must be at least 20 AWG (American Wire Gage), stranded, and tinned copper. Individual conductors must be insulated with PVC, PVC/nylon, vinyl, Teflon®*, or polyethylene. An aluminum/polyester 100% foil shield and an outer jacket of PVC, PVC/nylon, chrome vinyl, or Teflon with a minimum operating temperature range of –20 C to 60 C is required.

The communication bus shields must be tied together at each system element. If the communication bus is entirely within one building, the resulting continuous shield must be connected to ground at only one single point. If the communi- cation bus cable exits from one building and enters another building, the shields must be connected to the grounds at a lightning suppressor in each building (one point only).

Wiring Control Devices — Standard controls require no field wiring.

Standard controls for VAV applications include: duct static pressure (DSP), duct high static limit switch (DHS), compres- sor status (CSMUX), supply fan start/stop (SF), and supply fan speed (SPEED).

Field-installed devices and the factory-supplied supply air temperature sensor (required) will be wired to the field termi- nal block (TB2) provided. Refer to Fig. 26 and the following descriptions. This terminal is located in the control panel as shown in Fig. 27 and 28.

*Teflon is a registered trademark of E.I. du Pont de Nemours and Company.

SUPPLY AIR TEMPERATURE SENSOR (SAT) — The sup- ply air temperature sensor (Fig. 29) is used to measure the temperature of the air leaving the unit. The sensor should be located in the supply air duct, about 1 ft from the unit discharge connection (Fig. 30). On units with 2 fans, locate the sensor ap- proximately 5 duct diameters downstream from “pair of pants” duct connection, allowing for adequate mixing of supply air.

Mount the sensor as follows:

1.Remove the cover of the sensor junction box.

2.Drill a 7/16-in. hole at the selected location.

3.Install the sensor through the hole and secure using 2 no. 8 screws (provided). Do not overtighten.

4.Connect the sensor to the control box. Use an 18 or 20 AWG, 2 conductor, twisted pair cable. This cable is suitable for distances of up to 500 feet.

Connect the field wires to the supply air sensor using wire nuts or closed end style crimp connectors. Do not cut the sensor leads. Use the full length of lead supplied on the sensor.

In the control box, remove the jacket from the cable. Route the sensor wires over to the right hand side of the field terminal block (TB2). Strip the insulation back about 1/4-in. from each conductor. Connect the two wires to terminals 101 and 102 (SAT) on the terminal board. Polarity is not a consideration. See Table 11 for resistance vs. temperature values.

a50-7164tf

Fig. 26 — Field Terminal Block

28