Carrier Omnizone 50BVC Installation, Start-Up, Service And Controls Operation And Troubleshooting page 31

Control Wiring (VAV Only)
While most of the factory supplied and installed sensors are facto-
ry wired, some sensors are factory supplied for field installation or
are field supplied and installed. Factory supply, field installed sen-
sors include the supply air temperature (SAT) sensor, duct static
pressure (DPT) sensor, and return air temperature (RAT) sensors.
Refer to Table 14 for recommended cables.
Table 14 — Recommended Cables
MANUFACTURER
Alpha
American
Belden
Columbia
SUPPLY AIR TEMPERATURE SENSOR (SAT)
50BV VAV units ship with a factory installed supply air tem-
perature sensor in one of the blower housings. This sensor
should not be used for VAV operation. It is recommended to dis-
connect the factory sensor and utilized a field supplied and in-
stalled SAT sensor.
The field supplied supply air temperature sensor should be a duct
probe style thermistor (Carrier P/N 33ZCSENPAT) with a 10K-
type II resistance output curve (10K ohm at 77°F) that is wired
back to IN-6 of the unit controller. The duct probe sensor should
be installed in the supply duct at least 10 ft away from the unit or
any heat sources. See Fig. 22.
Fig. 22 — Supply-Air Temperature Sensor
Installation (Unit Discharge Location)
SMOKE DETECTOR/FIRE ALARM SHUTDOWN (FSD)
To allow a smoke detector to shut the 50BV unit down, field ter-
minate the sensor on IN-1 of the I/O Flex EX8160 expander. Use
the BACview tool to enable its operation.
PART NUMBER
2413 or 5463
A22503
8772
02525
31
REMOTE OCCUPANCY (ROCC)
The 50BV unit may be commanded by another control system or
a twist timer to become occupied and run when a set of dry con-
tacts close. In order for this to occur, wire the NO dry contacts to
UI-12 on the I/O Flex 6126 controller. From the BACview setup
screen, configure the occupancy command to be Digital Input.
RETURN AIR TEMPERATURE (RAT) SENSOR
VAV units will ship with 2-4 return air temperature (RAT) sensors,
which are used for determining load for cooling staging. The RAT
sensors must be field installed in the return air ductwork or in front
of the return air filter (free return) at various points to properly
sense the return air condition. The RAT sensors should be installed
near the unit to sense the true load on the unit (including any
mixed air). The RAT sensors are daisy chained and wired back to
UI-8 on the unit controller. See Fig. 23. See Table 15 for Thermis-
tor Resistance vs Temperature Values for Supply-Air and Return
Air Temperature Sensor.
0.50
2.25
O0.187
65º
NOTE: All dimensions are in inches.
Fig. 23 — Return Air Temperature Sensor
8.00
1.00
0.25
0.22
1.25
0.81
O0.187
(2 HOLES)