Honeywell C7046C User manual

® U.S. Registered Trademark
Copyright © 2004 Honeywell International Inc. • All Rights Reserved
INSTALLATION INSTRUCTIONS
62-0216
C7046A,B,C,D
Air Temperature Sensors
APPLICATION
The C7046 series of Air Temperature Sensors function
as primary and/or secondary sensors in electronic control
systems.
INSTALLATION
When Installing this Product...
1. Read these instructions carefully. Failure to follow
them could damage the product or cause a hazard-
ous condition.
2. Check the ratings given in the instructions and on
the product to make sure the product is suitable for
your application.
3. Installer must be a trained, experienced service
technician.
4. After installation is complete, check out product
operation as provided in these instructions.
CAUTION
Electrical Shock or Equipment Damage
Hazard.
Can shock individuals or short equipment
circuitry.
Disconnect power supply before installation.
The sensor assembly (see Fig. 1) consists of an
aluminum sensor probe (element housed internally) with
attached flange that can be mounted on a flat duct or
plenum surface, or in a 2 in. by 4 in. (51 by 102 mm)
junction box using two No. 8 screws. Connections to the
sensor are made through two 6 in. (152 mm) leadwires.
Fig. 1. C7046A,B,C,D Air Temperature
Sensor dimensions in in. (mm).
NOTE: Sensor probe diameter is 1/4 in. (6 mm).
Location
The sensor should be located in the air duct or plenum
where it will sample an average air temperature. Avoid
locations where air stratification can cause sensing
errors.
Mounting
Mounting on Flat Duct or Plenum Surface (Fig. 2)
1. Cut a 3/8 in. (9.5 mm) hole in the duct or plenum
surface at the desired location.
2. Insert sensor probe into the duct or plenum until
the flange rests against the duct or plenum wall.
3. If necessary, use the flange as a template to mark
and drill two holes for No. 8 mounting screws.
4. Fasten the sensor to the duct or plenum surface
with two No. 8 sheet metal screws (not provided).
Mounting in a Junction Box (Fig. 3)
1. Cut a 3/8 in. (9.5 mm) hole in the duct or plenum
surface at the desired location.
2. Remove the center rear knockout from the junction
box and insert the sensing probe through the
knockout with the flange flat against the outlet box.
3. Using the flange as a template, mark and drill two
holes in the junction box and the duct or plenum
surface for No. 8 mounting screws.
4. Insert sensor probe through both the junction box
knockout and the 3/8 in. (9.5 mm) hole drilled in the
duct or plenum and fasten the junction box and
sensor to the duct or plenum surface.
1/4
(
6
)
D
IAMETER
(
2 HOLES
)
M224
0
2
A
1
(
25
)
3
/4
(
19
)
2
(
51
)
1
(
25
)
1/16
(
2
)
8
(
203
)
NE
O
PRENE
G
A
S
KE
T
5/16
(
9
)
DIAMETE
R
(
BUSHING
)
L
OC
KIN
G
P
USH
NUTS
(
2
)
PLA
S
TI
C
B
US
HIN
G
1
INSERTION LENGTH DEPENDS UPON THE MODEL.
1

C7046A,B,C,D AIR TEMPERATURE SENSORS
62-0216 2
Fig. 2. Mounting C7046 Air Temperature
Sensor on a flat duct or plenum surface.
Fig. 3. Mounting C7046 Air Temperature
Sensor in a junction box.
Wiring
CAUTION
Electrical Shock or Equipment Damage
Hazard.
Can shock individuals or short equipment
circuitry.
Disconnect power supply before installation.
CAUTION
Erratic System Operation Hazard.
Failure to follow proper wiring practices can
introduce disruptive electrical interference
(noise).
Keep wiring at least one foot away from large
inductive loads such as motors line starters,
lighting ballasts, and large power distribution
panels.
Shielded cable is required in installations where
these guidelines cannot be met.
Ground shield only to grounded controller case.
IMPORTANT
1. All wiring must agree with applicable codes,
ordinances and regulations.
2. Do not mount sensor in incorrect environment.
3. Wire according to the applicable controller
instructions.
4. Erratic temperature readings from a sensor can
be caused by improper wiring practices. These
must be avoided to assure proper operation:
•Avoid poor wiring connections.
•Avoid intermittent or missing building earth
ground.
•Do not mount sensor in incorrect environment.
Connect low voltage wiring from the sensor to the
appropriate system component terminals using
solderless connectors. See Fig. 3.
NOTES:
1. For connections to the W973 Single Zone
Logic Panel, see Fig. 4.
2. For connections to the W7080 Multizone
System, see Fig. 5.
3. For connections to the Excel 500 Control
System, see Fig. 6.
4. For additional wiring information, refer to the
appropriate specification.
Fig. 4. Connecting C7046A Air Temperature
Sensor to a W973 Single Zone Logic Panel.
S
EN
SO
R
PR
O
B
E
SYSTEM DUCT
OR PLENUM
FLAN
GE
NO. 8
(
4mm
)
M
OU
NTIN
G
SC
REW
S
(
NOT PROVIDED
)
T
O
APPR
O
PRIAT
E
S
Y
S
TE
M
CO
MP
O
NENT
S
CO
NNE
C
T
S
EN
SO
R
WIRE
S
WITH TW
O
WIREN
U
T
CO
NNE
C
T
O
R
S
(
NOT PROVIDED
)
M22403
A
S
EN
SO
R
PR
O
B
E
S
Y
S
TEM
DUC
T
O
R
PLEN
UM
FLAN
GE
S
TANDARD
U
TILIT
Y
CO
ND
U
IT B
OX
CONNECTOR
L
OC
KN
U
T
AND
CO
ND
U
I
T
BLANK
FA
C
EPLAT
E
(
OPTIONAL
)
T
O
APPR
O
PRIATE
S
Y
S
TEM
CO
MP
O
NENT
S
CO
NNE
C
T
S
EN
SO
R WIRE
S
W
ITH TW
O
WIREN
U
T
CONNECTORS
(
NOT PROVIDED
)
M224
0
4
A
NO. 8 (4 mm)
MOUNTING
S
CREWS
(
NOT
PROVIDED
)
R
TT134251TRTRWBYR
SENSOR STAT 24 VAC ECONO
C +20 H N
1
C7046A
L1
(HOT)
L2
W973 LOGIC PANEL
M17965
1
POWER SUPPLY. PROVIDE DISCONNECT
MEANS AND OVERLOAD PROTECTION
AS REQUIRED.

C7046A,B,C,D AIR TEMPERATURE SENSORS
3 62-0216
Fig. 5. Connecting C7046B Air Temperature Sensor
for mixed air, cold deck and hot deck sensing, zone
discharge and optional remote return air sensing
in W7080 Multizone System.
Fig. 6. Connecting C7046D Air Temperature
Sensor to Excel 500 Control System.
OPERATION AND CHECKOUT
Operation
The C7046A,B,C Air Temperature Sensors consist of a
thermistor sensing element mounted in a tubular probe.
They are applied at various locations throughout single
zone and multizone duct systems. The negative
temperature coefficient (NTC) characteristic of the
thermistor element causes its resistance to decrease as
the sampled air temperature increases. This resistance
shift is balanced with other system sensor signals by
appropriate system logic panels to stabilize system
control.
The C7046D Air Temperature Sensor consists of a
platinum thin film sensor element mounted in a tubular
probe. It can be applied at various locations throughout
single zone and multizone duct systems. The positive
temperature coefficient (PTC) characteristics of the
platinum thin film element causes its resistance to
increase as the sampled air temperature increases. This
resistance shift is balanced with other system sensor
signals by the Excel 500 Control System.
Checkout
Allow the C7046 Air Temperature Sensor to soak in the
air moving through the duct or plenum for a minimum of
five minutes before taking a resistance measurement.
1. Disconnect the sensor leadwires from the associ-
ated system components.
2. Connect an ohmmeter across the leadwires.
3. Assure nominal resistance measurements are in
accordance with the resistance/temperature curves
shown in Figs. 7, 8 and 9.
4. Reconnect sensor leadwires to associated system
components.
5. Check operation of the complete control system.
Fig. 7. C7046A,C Sensor resistance vs. temperature.
M17966
A
C7046B
(OR C7100B)
MIXED AIR
SENSOR
C7046B
(OR C7100B)
COLD DECK
SENSOR
C7046B
(OR C7100B)
HOT DECK
SENSOR
21
HOT DECK HIGH LIMIT–A7
3456
90
110
130 NO JUMPER
78
24 Vdc
W7081
LIMIT CONTROLLER
21
COLD DECK LOW LIMIT–A6
3456
45
55
55 NO JUMPER
21
ECONOMIZER/MIXED AIR LOW LIMIT–A5
3456
50
55
60 NO JUMPER
+24 VDC
–+
T7080A,B C7046B
(OR C7100B)
ZONE (N)
DISCHARGE
SENSOR
2
3
1
8
6
5
7
4
C7046B
(OR C7100B)
REMOTE
RETURN
AIR SENSOR
(IF USED)
1
2
C7100B AVERAGING
TEMPERATURE SENSOR
MAY BE SUBSTITUTED IF
SPACE PERMITS.
REMOTE RETURN AIR
SENSOR USED WITH T7080B ONLY.
2
18
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
AI 1
AI 2
AI 3
AI 4
AI 5
AI 6
AI 7
AI 8
1
2
1
2
C7046D XF521A/XF526
M2825
4000
3000
2000
1000
8000
7000
6000
5000
12000
11000
10000
9000
16000
17000
15000
14000
13000
605040 70 8010 20 30 90 100
15 2010 25-5 0-10 530 35
RESISTANCE (OHMS)
TEMPERATURE (DEGREES)
M17969
F
C
3,000 OHMS
AT 77 F (25 C)

62-0216 B.B. 11-04 www.honeywell.com
C7046A,B,C,D AIR TEMPERATURE SENSORS
Automation and Control Solutions
Honeywell International Inc. Honeywell Limited-Honeywell Limitée
1985 Douglas Drive North 35 Dynamic Drive
Golden Valley, MN 55422 Scarborough, Ontario
M1V 4Z9
Fig. 8. C7046B Sensor resistance vs. temperature.
Fig. 9. C7046D Sensor resistance vs. temperature.
120000
100000
80000
60000
40000
20000
020 40 60 80 100 120 140
30 50 70 90 110 130
RESISTANCE (OHMS)
TEMPERATURE (DEGREES) M17973
0 10 20 30 40 C
F
-7 50 60
5 15 25
35 45 55
22,800 OHMS AT
77 F (25 C)
1159
1141
1126
1111
1096
1081
1066
1051
55 60 65 70 75 80 85 90 95 100 105
13 15 20 25 30 35 38 41
RESISTANCE
(OHMS)
TEMPERATURE (DEGREES) M2826
F
C
1097 OHMS AT
77 F [25 C]