48
Outdoor air management functions can be enha nced with
field--installation of these accessory control devices:
Enthalpy control (outdoor air or differential sensors)
Space CO
2
sensor
Outdoor air CO
2
sensor
Field Connections -- Field connections for accessory
sensors and input devic es are made the RTU--MP, at plugs
J1, J2, J4, J5, J11 and J20. All field control wiri ng that
connec ts to the RTU--MP must be routed through the
raceway built into the corner post as shown in Fig. 36.
The raceway provides the UL required clearance between
high-- and low--voltage wiring. Pass the control wires
through the hole provided in the corner post, then feed the
wires thorough the raceway to the RTU--MP. Connect to
the wires t o the removable Phoenix connectors and then
reconne ct the connectors to the board.
Space Temperature (SPT) Sensors
A field--supplied Carrier space temperature sensor is
required with the RTU--MP to monitor space temperature.
There are 3 sensors available for this application:
S 33ZCT55SPT, space temperature sensor with override
button
S 33ZCT56SPT, space temperature sensor with override
button and setpoint adjustment
S 33ZCT59SPT, space temperature sensor with LCD
(liquid c rystal di splay) scree n, overri de butt on, and
setpoint adjustment
Use 20 gauge wire to connect the sensor to the controller.
The wire is suitable for distances of up to 500 ft. Use a
three--conductor shielded cable for the sensor and setpoint
adjustment connections. If the set point adjustment
(slidebar) is not required, then an unshielded, 18 or 20
gauge, two--conductor, twisted pa ir cable may be used.
Connect T--55 — See Fig. 44 for typical T--55 interna l
connec tions. Connect the T--55 SEN terminals to
RTU--MP J20--1 and J20--2. (See Fig. 62.)
SEN
SEN
J20-1
J20-2
C08460
Fig. 62 -- RTU--MP T--55 Sensor Connections
Connect T--56 — See Fig. 46 for T--56 internal
connec tions. Install a jumper be tween SEN and SET
terminals as illustrated. Connect T --56 terminals to
RTU--MP J20--1, J20--2 and J20--3 per Fig. 63.
SEN J20-1
J20-2
SEN
SET
Jumper
J20-3
SET
C08461
Fig. 63 -- RTU--MP T--56 Sensor Connections
Connect T--59 — The T--59 space sensor requires a
separat e, isolated power supply of 24 VAC. See Fig. 64
for internal connections at the T--59. Connect the SEN
terminal (BLU) to RTU--MP J20--1. Connect the COM
terminal (BRN) to J20--2. Connect the SET terminal (STO
or BLK) to J20--3.
OR SET SEN
OPB COM- PWR+
BLU (SPT)
BLK (STO)
24 VAC
SENSOR
WIRING
POWER
WIRING
BRN (COM)
NOTE: Must use a separate isolated transformer.
C07132
Fig. 64 -- Space Temperature Sensor Typical Wiring
(33ZCT59SPT)
Economizer controls —
Outdoor Air Entha lpy Control (PNO HH57AC077) --
The enthalpy control (HH57AC077) is availa ble as a
field--installed accessory to be used with the EconoMi$er2
dampe r system. The outdoor air enthalpy sensor is part of
the enthalpy control. (The separate field--installed
accessory return air entha lpy sensor (HH57AC078) is
required for differential enthalpy control. See below.)
48TC