Carrier /50HC 04-28, Controls, Start-Up, Operation And Troubleshooting, Page: 81 / 144

81
48/50HC 04-14 Units — Low Voltage Terminal
Board (TB)
The field connection terminal board has 30 terminals oriented
in 3 rows of 10 terminals. The front has screw terminals and
the back has spade connectors. This board provides connection
for the thermostat, space sensor, and most field installed acces-
sories. See Table 32.
Table 32 — Field Connection Terminal Board (TB) Connections (04-14 Size Units)
*Point name displayed on the scrolling marquee or Navigator display.
TERMINAL
LABEL
DISPLAY NAME* DESCRIPTION SENSOR LOCATION TYPE OF I/O TERMINAL NUMBER
C- 2 Transformer 2 Common 24 VAC common 1,2
R- 2 24 VAC power Transformer 2 24 VAC 9,10
SPT+ SPT Space temperature (T55/56) space 10k thermistor 14
SPT- SPT Space temperature (T55/56) space 10k thermistor 13
SPTO SPTO Space temperature offset (T56) space 10k thermistor 12
FDWN FDWN Fire shutdown switch input supply/return/space 24 VAC input 30
X ALRM Alarm output (normally open) space 24 VAC output 3
G G Thermostat G (Fan) space 24 VAC input 4
W1 W1 Thermostat W1 (1st stage heat) space 24 VAC input 5
W2 W2 Thermostat W2 (2nd stage heat) space 24 VAC input 6
Y1 Y1 Thermostat Y1 (1st stage cool) space 24 VAC input 7
Y2 Y2 Thermostat Y2 (2nd stage cool) space 24 VAC input 8
RAT RAT Return Air Temperature Sensor return duct 10k thermistor 15,16
SAT SAT Supply Air Temperature Sensor Blower or duct 10k thermistor 17,18
HUM HUM Humidistat switch input supply/return/space switch input 27
LPWR Analog Sensor Loop power (24vdc) 24 VDC 24
COM Analog sensor common Ground 22
IAQ IAQ Indoor air quality sensor return/space 4- 20 mA input 23
SPRH SP.RH or OAQ
Relative humidity sensor or Outdoor
air quality sensor
field installed 4-20 mA input 21
RMOC RM.OC Remote occupancy switch field installed 24 VAC input 25
ENTH ENTH or IAQ.S
Outdoor enthalpy switch, or Indoor
air quality switch
economizer, or return/
space
24 VAC input 26
Not Used 11,19,20,28,29