Low Voltage Terminal Strip (Tb1) - Carrier 48/50PG Series Controls, Start-Up, Operation, Service And Troubleshooting Instructions

Low Voltage Terminal Strip
(TB1 on PG03- -16 size and TB2 on PG20- -28 and
PM16- -28 size units)
This circuit board provides a connection point between the major
control boards and a majority of the field-installed accessories. (See
Fig. 48 and Table 26.)
17
J10
SEPARATION OF CIRCUITS TO EACH 24V TRANSFORMER MUST BE MAINTAINED
1 2 3 4 5 6
DISPLAY
TERMINAL LABEL
1
2 IAQ
3
OAQ or
4
SP .RH
5 RM.OC
6
ENTH or
7
IAQ.S
8* EC.CP
9
10* EC.AP
R
Y1 Y1
Y2 Y2
W1 W1
W2 W2
G G
C
X ALRM
FIRE SHUTDOWN FDWN
or or
HUMIDISTAT 1* HUM
FIRE SHUTDOWN FDWN
or or
HUMIDISTAT 2* HUM
T55
SPT
1 ---2
T55 SPTO or
2 ---3 RAT
FAN STATUS
1 ---2
LEN
CCN
* Refer to Third Party Control section for more information
14
J11
7 8 9 10 R Y1 Y2 W1 W2 G
Fig. 48 - - Low- -Voltage Terminal Strip
Table 26 – Field Connection Terminal Strip
POINT DESCRIPTION
NAME
24 VDC Sensor Loop power
Indoor air quality sensor
Air quality & humidity sensor common
Outdoor air quality sensor or
Relative humidity sensor
Remote occupancy switch
Switch power (ENTH, RM.OC, IAQ.S)
Outdoor enthalpy switch, or
Indoor air quality switch
Economizer commanded position actu-
ator (when in digital control)
Economizer signal common
Economizer position feedback (when in
analog control)
24 VAC power
Thermostat Y1 (1st stage cool)
Thermostat Y2 (2nd stage cool)
Thermostat W1 (1st stage heat)
Thermostat W2 (2nd stage heat)
Thermostat G (Fan)
24 VAC common
Alarm output (normally open)
Fire shutdown switch 24 VAC output
or
Humidistat switch input
Fire shutdown switch input
or
Humidistat switch 24 VAC output
Space temperature (T55/56)
Space temperature offset (T56) or
Return air temperature
NOT USED
Local Equipment Network (LEN)
Carrier Comfort Network (CCN)
The circuit breakers for the low voltage control transformers,
interface connection for the Carrier Comfort Network® (CCN)
communication, and interface connection for the Local Equipment
Network (LEN) communications are also located on the low
voltage terminal strip.
7
7
RUN TEST
J12
T55
FIRE SHUTDOWN
C X 1 2 1 2
SENSOR
LOCATION
return/space
field installed
field installed
economizer, or
return/space
economizer 2 ---10 VDC output
economizer
2 ---10 VDC output
space
space
space
space
space
supply/return/
space
supply/return/
space
space
space or return
80
J13
8
(+) (COM) (-) SHIELD
FAN STATUS
CCN
3 1 2
LEN
CCN
C07029
CONNECTION
TYPE OF I/O
PIN NUMBER
24 VDC output J10, 17
4 ---20 mA input J10, 16
Ground J10, 15
4 ---20 mA input J10, 14
24 VAC input J10, 13
24 VAC output J10, 11 ---12
24 VAC input J10, 9 ---10
J10, 6 ---8
Ground J10, 3 ---5
communication
J10, 1 ---2
24 VAC output J11, 11 ---14
24 VAC input J11,10
24 VAC input J11, 9
24 VAC input J11, 7 ---8
24 VAC input J11, 6
24 VAC input J11, 5
24 VAC output J11, 2 ---4
24 VAC output J11, 1
switch input J12, 7
switch input J12, 6
10k thermistor J12, 4 ---5
10k thermistor J12, 3 ---4
J12, 1 ---2
communication J13, 1 ---3, 4 ---5
communication J13, 6 ---8, 4 ---5