Install Instructions

T7350 COMMERCIAL PROGRAMMABLE THERMOSTAT
Automation and Control Solutions
Honeywell International Inc.
1985 Douglas Drive North
Golden Valley, MN 55422
Honeywell Limited-Honeywell Limitée
35 Dynamic Drive
Toronto, Ontario M1V 4Z9
customer.honeywell.com
® U.S. Registered Trademark
© 2010 Honeywell International Inc.
62-0195—06 K.K. Rev. 06-10
Printed in U.S.A.
DEHUMIDIFICATION (T7350D,H,M)
There are five methods through which the T7350 can
control for dehumidification. Three of them modify the
control algorithm, thus providing limited dehumidification
through cooling. The other two use the auxiliary output to
control another device.
IMPORTANT
Configurable only with a PDA.
NOTE: The dehumidification high limit can be set within
the range of 10 to 90 percent relative humidity.
Control Through Cooling
Configure using some combination of the following:
— Minimum On.
— Reheat.
— Reset.
NOTES:
— These methods operate only during cooling.
— Selecting both Reheat and Reset options
can cause frequent setpoint adjustments.
This selection is not recommended.
Min. ON Time
Dehumidifies by increasing the compressor minimum on
time (normally 3 minutes) by a programmable amount.
This is useful with oversized systems in that it forces the
coils to cool to a point where dehumidification can occur.
NOTES:
— Can force wider temperature swings by
cooling when setpoint control does not
require it.
— The minimum on time can be set within the
range of 5 to 15 minutes.
— Hysteresis and a minimum timer are used to
ensure this behavior does not change with
every equipment cycle.
Reheat
Dehumidifies by operating cooling during typical off time.
The T7350 maintains the proper setpoint by running the
heat at the same time.
IMPORTANT
At times during Reheat dehumidification, the
T7350 operates heating and the cooling
simultaneously. This is normal.
NOTES:
— The heat stage never energizes during
Reheat if more than one cool stage is on.
— Reheat mode cannot occur during heating.
— The T7350M does not support the Reheat
method.
Reset Temp SetPt
The room temperature setpoint resets to a specified
number of degrees below the actual setpoint when room
relative humidity (RH) rises above humidity high limit
setpoint.
Though this may not technically reduce relative humidity
in the room, it reduces the dew point to provide the
customer with a sense of comfort due to a lower
temperature setting in the room.
As long as RH stays above humidity high limit setpoint,
this setpoint is maintained.
NOTE: Hysteresis and a minimum timer prevent the
setpoint from short interval alternation (between
standard and reset setpoints).
Options Utilizing Auxiliary Output
There are two dehumidification options that utilize the
auxiliary output. They are:
— Simple Dehumidification.
— Hot Gas Bypass Dehumidification.
Simple Dehumid(ification)
The auxiliary output:
— Energizes when RH rises above humidity high limit.
— De-energizes when RH drops below humidity high limit.
NOTES:
— Hysteresis and a minimum timer prevent
short cycling of this output.
— Unlike Dehumid Hot Gas BP the relay
remains energized during calls for multiple
cooling stages.
Dehumid Hot Gas BP
The auxiliary output operates as shown in Table 5.
Table 5. Hot Gas Bypass Dehumidification Logic.
Auxiliary output during call for multiple cooling stages for
two reasons:
1. This method assumes that the cooling provides
dehumidification.
2. Multiple cooling stages probably provide necessary
dehumidification.
NOTE: Hysteresis and a minimum timer prevent short
cycling of this output.
Humidity Cooling Stages Active Auxiliary Output
High more than one De-energized
High one or less Energized
Low more than one De-energized
Low one or less De-energized
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