Carrier 33CSPREMLK Outdoor Air Temperature Sensor, Installation - Located in Building Wall

Fig. 16 — Outdoor Air Temperature Sensor

Installation — Located in Building Wall

2 x 4 x 1.5 IN. ELECTRICAL BOX (FIELD SUPPLIED)

1/4" BEAD SILICONE SEALER

1.125"

DIA.

HOLE

OAT SENSOR

OA

DUCT

1/2" CONDUIT NUT

2 #10 DRILL/TAP SCREWS (FIELD SUPPLIED)

OUTSIDE AIR DUCT

DUCT MOUNTED (EXPLODED VIEW)

LEGEND

OA — Outdoor Air

OAT — Outdoor Air Temperature

Fig. 17 — Outdoor Air Temperature Sensor Installation — Located in Outdoor Air Duct

Connect to CCN Communication Bus — The PremierLink™ controller connects to the bus in a daisy chain arrangement. Negative pins on each component must be connected to respective negative pins and likewise positive pins on each component must be connected to respective positive pins. The controller signal pins must be wired to the signal ground pins. Wiring connections for CCN must be made at the 3-pin plug.

At any baud (9600, 19200, 38400 baud), the number of con- trollers is limited to 239 devices maximum. Bus length may not exceed 4000 ft, with no more than 60 total devices on any 1000-ft section. Optically isolated RS-485 repeaters are required every 1000 ft.

NOTE: Carrier device default is 9600 baud.

COMMUNICATION BUS WIRE SPECIFICATIONS — The CCN Communication Bus wiring is field-supplied and field-installed. It consists of shielded three-conductor cable with drain (ground) wire. The cable selected must be identical to the CCN Communication Bus wire used for the entire net- work. See Table 4 for recommended cable.

Table 4 — Recommended Cables

MANUFACTURER	CABLE PART NO.
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).

Enthalpy and Differential Enthalpy Control (Fig. 18-23) — There are two options for field-supplied enthalpy and differential enthalpy control: the enthalpy switch/ receiver option, and the outdoor and return air sensor option. Either option can be used to indicate when the outdoor air is suitable for free cooling.

ENTHALPY SWITCH/RECEIVER — The accessory en- thalpy switch/receiver (33CSENTHSW) senses temperature and humidity of the air surrounding the device and calculates the enthalpy when used without an enthalpy sensor. The relay is energized when enthalpy is high and deenergized when enthalpy is low (based on ASHRAE 90.1 criteria). If an acces- sory enthalpy sensor (33CSENTSEN) is attached to the return air sensor input, then differential enthalpy is calculated. The relay is energized when the enthalpy detected by the return air enthalpy sensor is less than the enthalpy at the enthalpy switch/ receiver. The relay is deenergized when the enthalpy detected by the return air enthalpy sensor is greater than the enthalpy at the enthalpy switch/receiver (differential enthalpy control). See Fig. 18 and 19.

Outdoor Enthalpy Control Installation (Fig. 20) — Outdoor enthalpy control requires only an enthalpy switch/receiver (33CSENTHSW). The enthalpy switch/receiver is mounted in the outdoor air inlet and calculates outdoor air enthalpy. The enthalpy switch/receiver energizes the relay output when the outdoor enthalpy is above 28 BTU/lb OR dry bulb temperature is above 75 F and is deenergized when the outdoor enthalpy is below 27 BTU/lb AND dry bulb temperature is below 74.5 F. The relay output is wired to the unit economizer which will open or close depending on the output of the switch.

NOTE: The enthalpy calculation is done using an average alti- tude of 1000 ft above sea level.

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