INSTALLER'S GUIDE
18-HH08D10-2
Page 6
INSTALLATION WITH 4" BOX
*
CONNECTIONS MAY BE
SOLDERED, IF DESIRED
*
4
4
4
4
4
WIRING:
The connections from the Discharge Air Sensor to the
system controller can be made with standard two wire
thermostat wire (#18 A.W.G. minimum).
CAUTION:
Keep this wiring at least one foot away
from large inductive loads such as electronic air
cleaners, motors, line starters, lighting ballasts and
large distribution panels. Failure to follow these
wiring practices may introduce electrical interfer-
ence (noise) which can cause erratic system opera-
tion. All unused thermostat wire to be grounded at
controller end only. Shielded cable is required if the
above wiring guidelines cannot be met. Ground the
shield only to the system controller case.
Make the connections to the sensor leads with wire nuts or
other solderless connectors (see Figure 4). The Discharge
Air Sensor is connected to the System Controller at
terminals “C” and “T2” as indicated in Figure 5. Connect
either lead to terminal “C” and the other to terminal “T2”.
NOTE: Do not run sensor wiring in conduit with
other wiring.
CHECKOUT:
To check for a failed sensor, disconnect the two sensor
leads from the associated wiring. After the sensor has
“soaked” for a minimum of five minutes in the discharge
air stream, measure the temperature of the air in the
duct and record. Connect an accurate ohmmeter across
the two leads of the sensor and record the resistance
value thus obtained. Compare the values obtained
(temperature and resistance) to the values indicated by
the curve in Figure 6. A reading within 10% of the
indicated value is acceptable.
DISCHARGE AIR
SENSOR
SYSTEM CONTROLLER
TB4
T1
T2
T3
C
CONNECTIONS AT SYSTEM CONTROLLER
5
5
5
5
5
RECOMMENDED ZONE CARD SETTINGS FOR
SUPPLY DUCTWORK DAMPERS TABLE:
This table contains useful information for the installer and
the service mechanic to help in setting up or checking out
a zoned system. The total system airflow must first be
established to determine the proper zone weights. All
values in the table are based on a
recommended airflow
velocity of 600 fpm for branch ducts (B)
suppling air to
a grill or register and
1000 fpm for main ducts (M)
suppling air to branch ducts constructed of unlined, smooth
sheet metal. Enter the table for total system airflow at the
top of the column, and the selected damper diameter in the
far left column, and look under the
(B) branch
or the
(M)
main
column for the
WT
(weight value 1-7) for the branch
or main duct and using the table in Figure 13 for Zone
control Card Switch Settings, set the three dip switches on
the zone control card to the appropriate weight. If two or
more dampers connect to the same zone control card, the
weight setting is based on the percent of total airflow that
these dampers will control as shown in Figure 13.
TEMPERATURE/RESISTANCE CURVE
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