INSTALLATION INSTRUCTIONS
APPLICATION
The C7735A1000 Discharge Air Temperature Sensor
INSTALLATION
When Installing this Product...
(DATS) is a duct-mounted temperature probe that
provides capacity control of heating and cooling
equipment. The DATS is used only with zoning solutions,
including TZ-3, MABS EZ-2 and MABS EZ-4, and EMM3 and EMM-3U control panels. Mounted in the supply air
duct, the DATS senses the delivered air temperature and
cuts off the heating or cooling when the delivered air
temperature goes above or below normal operating
limits.
When either limit setting is reached, the appropriate heat
or cool light emitting diode (LED) flashes on the TZ-3 or
EMM series panels, indicating that heating or cooling is
shut off. The call still exists and heated or cooled air is
still being supplied to the calling zones. Once the
delivered air temperature drops ten degrees for heating,
or rises ten degrees for cooling, the heating or cooling
equipment is brought back on. The ten-degree
differential provides adequate minimum time-off to avoid
damaging the equipment. EMM series has a 2.5 minute
timer as equipment protection.
The location of the DATS is critical; it should not be
placed in line-of-sight of the heat exchanger or cooling
coil because the DATS could activate prematurely. It
should also be located before the bypass damper, when
applicable. DATS dimensions are shown in Fig. 1.
The DATS requires only two wires. Normal 18 to 22
gauge thermostat wire is used for shorter runs. For
longer runs or when wiring near voltage, shielded cable
is used.
1-1/4
(25)
3-3/4
(77)
M14926
3-7/8
(77)
4-1/8 (102)
Fig. 1. C7735A dimensions in in. (mm).
Read these instructions carefully. Failure to follow
1.
them could damage the product or cause a hazardous condition.
Check the ratings given in the instructions and on
2.
the product to make sure the product is suitable for
your application.
Installer must be a trained, experienced service
3.
technician.
After completing installation, use these instructions
4.
to check out the product operation.
IMPORTANT
Do not locate the DATS probe in a duct near the
heat exchanger or strip heat, which can cause
false temperature readings.
Locate the DATS on the supply trunk between the
1.
bypass damper and the evaporator coil and/or heat
exchanger. If a bypass damper is not used, locate
the DATS between the zone dampers and the
evaporator coil and/or heat exchanger. See Fig. 2.
ZONE DAMPERS
BY PASS DAMPER
PLACE SENSOR
INTHIS AREA.
EVAPORATOR COIL
HEAT EXCHANGER
BLOWER
Fig. 2. DATS mounting location.
DO NOT
PLACE
SENSOR IN
THIS AREA.
M14877
® U.S. Registered Trademark
Copyright © 2001 Honeywell • • All Rights Reserved
69- 1521- 2
C7735A1000 DISCHARGE AIR TEMPERATURE SENSOR
TROUBLESHOOTING
C7735A WITH
COVER REMOVED
TL
TL
ZoneMAX
ZONING PANEL
M14879
Drill a 1/4 in. hole in the duct at the location
2.
selected for the sensor.
Remove the cover from the DATS case and insert
3.
the probe into the hole drilled in step 2.
Secure the DATS to the side of the duct, through
4.
the two mounting holes in the back of the case,
with the screws supplied.
IMPORTANT
Use normal 18-22 gauge thermostat wire for
shorter runs. For longer runs or when wiring
near voltage, use shielded cable.
Check the resistance across the sensor leads and
5.
cross reference with Table 1.
Connect the two DATS wires, using the wire nuts
6.
supplied, to wires that connect to the TL and TL
terminals on the TZ-3, MABS EZ-2, MABS EZ-4 or
to the ZMS and ZMS terminals on the EMM series
panels, through the wiring hole in the DATS case.
See Fig. 3.
Replace the cover on the DATS case.
7.
Adjust the MAX Temp dial on the TZ-3 to the
8.
appropriate high limit setting. This can be set
between 110°F and 160° F (43°C and 71°C). Note
that settings between the lines are approximate
settings. The cooling low limit is fixed at 40 °F
(4°C) on the TZ-3, Rev 2 and 3 panels. The TZ-3,
Rev 4 panel, can be set at either 40 °F (4°C) or
48 °F (9°C). See TZ-3 panel instructions for further
information.
Set the upper and lower limits on the EMM-3U
9.
using DIP switches 5 and 6.
Fig. 3. DATS wiring to TZ-3 panel.
When Zoning Panel LED is... It means... It is corrected when...
Flashing IDLE light five times on
initial power-up (TZ-3).
Flashing IDLE continuously (TZ-3).
Flashing system light (EMM-3).
Flashing purge light (EMM-3U).
Flashing HEAT light continuously. DATS has tripped on high temper-
Flashing COOL light continuously DATS has tripped on low
See Table 1 for readings in resistance for each temperature to determine if the DATS is reading the correct
temperature. To obtain the correct resistance measurement, remove the two wires from the wire nuts and measure the
resistance across the two wires.
No DATS is wired to the panel or
there is an open circuit.
A DATS failure or no sensor. Unhook the loads and verify the resistance
ature limit and all stages of heating
are shut off.
temperature limit and all stages of
cooling are shut off.
Circuit is closed. Note that the DATS
Sensor is optional and not required for the
TZ-3 to operate.
using step 5 of the Installation instructions.
Reset because delivered air temperature
drops 10ºF (-12°C) from MAX Temp setting
on the TZ-3 panel. 2.5-minute minimum
wait required on EMM series panels.
Reset because delivered air temperature
rises 10ºF above fixed low temperature
setting of 40°F (4°C) on TZ-3, Rev 2 and 3
panels, or 40º and 48°F (4°C and 9°C) on
TZ-3, Rev 4 panels. 2.5-minute minimum
wait required on EMM series panels.
69-1521-2 2