Carrier 50HT-A07 Installation Instructions Manual page 17

Comfort Network or as a stand alone control) or the
RTU- - MP Controller for Building Management Systems
using non- - CCN protocols (RTU- - MP is available as a
factory- - installed option only).
Thermostat —
Install a Carrier- - approved accessory thermostat according
to installation instructions included with the accessory.
For complete economizer function, select a two- - stage
cooling thermostat. Locate the thermostat accessory on a
solid wall in the conditioned space to sense average
temperature in accordance with the thermostat installation
instructions.
If the thermostat contains a logic circuit requiring 24- - v
power, use a thermostat cable or equivalent single leads of
different colors with minimum of seven leads. If the
thermostat does not require a 24- - v source (no "C"
connection required), use a thermostat cable or equivalent
with minimum of six leads. Check the thermostat
installation instructions for additional features which
might require additional conductors in the cable.
Using unit- - mounted convenience outlets: Units with
unit- - mounded convenience outlet circuits will often
require that two disconnects be opened to de- - energize all
power to the unit. Treat all units as electrically energized
until the convenience outlet power is also checked and
de- - energization is confirmed. Observe National Electrical
Code Article 210, Branch Circuits, for use of convenience
outlets.
For wire runs up to 50 ft. (15 m), use no. 18 AWG
(American Wire Gage) insulated wire [35_C (95_F)
minimum]. For 50 to 75 ft. (15 to 23 m), use no. 16 AWG
insulated wire [35_C (95_F) minimum]. For over 75 ft.
(23 m), use no. 14 AWG insulated wire [35_C (95_F)
minimum]. All wire sizes larger than no. 18 AWG cannot
be directly connected to the thermostat and will require a
junction box and splice at the thermostat.
Unit without thru- - base connection kit —
Pass the thermostat control wires through the hole
provided in the corner post; then feed the wires through
the conduit built into the raceway of the corner post to the
control box. Pull the wires over to the terminal strip on the
upper- - left corner of the Controls Connection Board. See
Fig. 27.
NOTE: If thru- - the- - bottom connections accessory is
used, refer to the accessory installation instructions for
information on routing power and control wiring.
Ttypical
Thermostat
Corrections
C
G
W2
(Note 3)
W1
O/B/Y2
(Note 1) (Note 2)
Y1
R
Note 1: Typical multi-function marking. Follow manufacturer's configuration
instructions to select Y2.
Note 2: Y2 to Y2 connection required on single-stage cooling units when
integrated economizer function is desired
Note 3: W2 connection not required on units with single-stage heating.
Field Wiring
Fig. 26 - - Low- - Voltage Connections
RACEWAY
HOLE IN END PANEL (HIDDEN)
Fig. 27 - - Field Control Wiring Raceway
NOTE: If thru- - the- - bottom connections accessory is
used, refer to the accessory installation instructions for
information on routing power and control wiring.
Heat Anticipator Settings —
Set heat anticipator settings at 0.14 amp for the first stage
and 0.14 amp for second- - stage heating, when available.
Electric Heaters
50HT units may be equipped with field- - installed
accessory electric heaters. The heaters are modular in
design, with heater frames holding open coil resistance
wires strung through ceramic insulators, line- - break limit
switches and a control contactor. One or two heater
modules may be used in a unit.
Heater modules are installed in the compartment below
the indoor (supply) fan outlet. Access is through the
indoor access panel. Heater modules slide into the
17
Central
Terminal
Board
X
C
T
H
G
E
R
W2
M
O
W1
S
T
Y2
A
T
Y1
R
C08575
C08027