Advanced Operation; Control Response Rate; Dehumidification; Dehumidifier Operation - Trane TCONT824 Installation Manual

7.

Advanced Operation

7.1

Control response rate

Allows the user to select a set of higher proportional-
integral control constants to increase the responsiveness
of the Control. Selecting "Fast" will cause the Control to
generate load value at a faster rate. Control Response rate
can be adjusted in Installer Setup>Comfort Settings.
7.2

Dehumidification

The 824 utilizes the following methods for dehumidification:
• Air flow reduction (applies only to variable speed
blowers) – If BK is connected, the 824 can reduce
the system air flow by 30% anytime the indoor RH is
higher than the cooling RH target. Air flow reduction is
disallowed if the indoor temperature is more than 2°F
above the cooling setpoint. Dehumidification is factory
enabled in the Installer Setup>Comfort Settings.
All "Fan Off" delays are also defeated when
dehumidification is enabled and the indoor RH
exceeds the cooling RH target.
• Overcooling (applies to variable speed and non-
variable speed blowers) - If overcooling is enabled,
the Control will allow a 0.1°F of overcooling for each
1% of RH error. A maximum amount of overcooling
can be configured for 1°, 2° or 3°F.
EXAMPLE OF OVERCOOLING
WITH MAXIMUM CONFIGURED AT 2°
TARGET ACTUAL
HUMIDITY HUMIDITY
40% 45%
40% 55%
40% 65%
40% 70%
When the system
Dehumidification will be displayed on the 824 home
screen. The maximum amount of overcooling is
configured in Installer Setup>Comfort settings.
• Smart Continuous Fan (applies to variable speed and
non-variable speed blowers) – If enabled, continuous
fan operation will be interrupted when indoor RH
exceeds desired cooling RH target. A humidity icon
will be displayed along with the fan icon to indicate
that continuous fan operation has been disabled due
to high humidity conditions. Smart Continuous Fan
will not interrupt the fan circulate mode. This feature
can be enabled in the Installer Settings>Comfort
Settings>Smart Continuous Fan settings.
7.3

Dehumidifier Operation

The 824 has the ability to control a Whole-House
Dehumidifier through the normally open dry AUX contacts
on the 824 Control Sub-base. Control options are:
• Stand Alone Operation – Dehumidifier can operate
independent from cooling operation as long as the
18-HD72D1-6
PERCENT DEGREES OF
OF RH OVERSHOOT
ERROR
5% 0.5° Overshoot
15% 1.5° Overshoot
25% 2.0° Overshoot
30% 2.0° Overshoot
is actively overcooling,
824 Programmable Wi-Fi Comfort Control
824 Control is in Cooling mode or Auto mode and the
last call was cooling.
If Stand Alone Operation is selected, the 824 Control
allows the user to select whether the indoor fan
operates with dehumidifier request.
• With Active Call for Cooling Only – Dehumidifier can
only operate during an active call for cooling.
All dehumidifier control options are located in the
Installer Setup>Accessories Settings.
7.4

Dual Fuel Operation

The 824 can control a dual fuel system without the need of
an external dual fuel kit. An Outdoor Temperature Sensor
must be installed and enabled for Restricted Modes to be
available. The 824 Control options are:
• Non Restricted Mode – The Control will determine
which mode of heat will operate to maintain comfort
based on the calculated system load value. With a load
value in compressor heating range the heat pump will
operate and if the load value climbs to auxiliary heat
range, the heat pump will cycle off and the auxiliary
heat source will cycle on. Once the load value falls
below the auxiliary heat range, the auxiliary heat will
cycle off, and the heat pump will cycle back on.
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