Remote Condenser Fan Contactor Wiring; Control Wiring (Vav Only) - Carrier Omnizone 50BVC Installation, Start-Up, Service And Controls Operation And Troubleshooting

REMOTE CONDENSER FAN CONTACTOR WIR-
ING — For unit sizes 020-034, one remote condenser is re-
quired. Install a field-supplied 24-v pilot relay (Aux relay) be-
tween Y1 and C. This will energize the FC contactor on the re-
mote condenser whenever there is a call for cooling.
For unit sizes 044-064, 2 remote condensers are required. Be
sure to make piping connections so that compressors 1 and 2 are
connected to condenser 1, and compressors 3 and 4 are connect-
ed to condenser 2. Use an additional set of NO (normally open)
contacts on PR1 to energize FC1 on condenser 1, and a set of
NO contacts on PR2 to energize FC1 on condenser 2.
CONTROL WIRING (VAV ONLY) — The VAV units are
designed to operate either with a building management
system or stand alone (local control). See Table 14 for ca-
ble recommendations.
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
UNIT MODULE 'A'
C O Y1
LEGEND
FC — Fan Contactor
PR — Pilot Relay
*Teflon is a registered trademark of E.I. du Pont de Nemours and
Company.
FIELD-SUPPLIED THERMOSTAT
C O Y1
Y3 R G
PR2
PR1
Fig. 14 — Typical Wiring 40 to 60 Ton Units (Two-Stage Cooling)
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), compressor status (CHC1FLD), 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 in the field to the
unit's direct digital control.
THERMOSTAT
B
O
Y2 R W1 Y1 G C
2nd STAGE COMPRESSOR RELAY
Fig. 13 — Typical Wiring Unit Sizes 020-034
(Two-Stage Cooling Units)
Y2 R G
UNIT MODULE 'B'
C O Y2
Remote Condenser Units Only
(#1)
(#2)
22
a50-7272ef
24 VAC COMMON
FAN RELAY
COMPRESSOR RELAY
HEAT PUMP
24 VAC RETURN
PR1
PR2
a50-7273ef
G
Y4 R
FC1-4 FC1-5
PR1
FC1-4 FC1-5
PR2
TYPICAL
UNIT
C
O
Y1
Y2
R
G