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T10 PRO SMART THERMOSTAT WITH REDLINK
and weather history, allowing the thermostat to start
recovery at the optimal time so it can reach the
programmed temperature setting at the programmed
time. The T10 thermostat uses two recovery ramps when
setup to control a heat pump system. One ramp for the
compressor and one ramp for the auxiliary heat. Once the
room temperature intersects the compressor ramp, the
compressor turns on until the setpoint is reached. If the
room temperature does not rise quickly enough and
intersects the second ramp, the auxiliary heat turns on. It
takes about one week for the thermostat to adjust to
weather conditions, equipment performance and
construction of the home. If the temperature setting is
reached too early or too late, the ramp is adjusted for the
next day's recovery. See Fig. 48.
Fig. 48.
Compressor Protection
The thermostat keeps the compressor off for a few
minutes before restarting, to prevent equipment damage.
During this "off" time, the message "Wait" is displayed on
screen.
P + I Control
A conventional mechanical or electronic thermostat does
not control temperature precisely at setpoint. Typically
there is an offset (droop) in the control point as the system
load changes. Many factors contribute to offset including
the switch differential, thermal lag, overshoot, cycle rates
and system load.
The T10 thermostat however, works much differently than
a conventional mechanical or electronic Thermostat when
droop is set to comfort. Droop is always set to comfort and
not adjustable when controlling a 2 stage furnace or 2
stage heat pump without aux heat. The proprietary
algorithm in the thermostat eliminates the factors causing
offset (droop). This makes temperature control more
accurate than the conventional mechanical or electronic
thermostat. The temperature control algorithm is called
proportional plus integral (P + I) control.
The thermostat sensor or indoor sensor senses the current
space temperature. The proportional error is calculated by
comparing the sensed temperature to the setpoint
temperature. The deviation from the setpoint is the
proportional error.
The thermostat also determines integral error, which is a
deviation based on the length of error time (how long the
sensed room temperature has been away from the
setpoint temperature). The sum of the two errors is the (P +
I) error.
33-00462—01
COMPRESSOR SETPOINT
AUXILIARY HEAT SETPOINT
ROOM TEMPERATURE
WAKE
M6406C
The cycle rate used to reach and maintain the setpoint
temperature is computed using the P + I control algorithm.
The addition of the integral error is what differentiates the
thermostat from many other mechanical and electronic
thermostats.
Heat Differential
For stage 2 of conventional systems or 2 stage heat-
pump without aux heat
The thermostat will use the stage of heating as needed to
keep the indoor temperature within 1 °F (0.5 °C) degree of
the setpoint. The thermostat turns on stage 2 when the
capacity on stage 1 reaches 90%.
Heat pumps with electric aux heat when droop is set to
"comfort"
The thermostat will use the stage of heating as needed to
keep the indoor temperature within 1 °F (0.5 °C) degree of
the setpoint. The thermostat turns on Aux heat when the
capacity on highest compressor stage has reaches 90%.
Heat pumps with electric aux heat when droop is set to
2°F or higher
(2 °F to 15 °F adjustable)
If the indoor temperature drops to the droop amount while
the highest compressor stage is running the thermostat
will continue to run the heatpump stages and also
energize the Aux heat.
For example, if the Backup Heat Droop is set to 2 °F (1.0
°C), the indoor temperature must drop 2 °F (1.0 °C) below
the setpoint while the previous stage is running before the
backup heat turns on. Raising setpoint manually or by a
schedule change does not cause droop to run the backup
heat. When droop is set to other than comfort, the upstage
timer setting is also available.
Dual fuel Heat pumps with gas or oil backup heat
If thermostat is configured to control dual fuel, the droop
cannot be set to comfort. It will default to 2 °F and can be
adjusted from 2 °F to 15 °F.
If the indoor temperature drops to the droop amount while
the highest compressor stage is running the thermostat
will end the call for the heatpump stages and run the fossil
fuel heat stage.
For example, if the Backup Heat Droop is set to 2 °F (1.0
°C), the indoor temperature must drop 2 °F (1.0 °C) below
the setpoint while highest heatpump stage is running
before the thermostat will shut down the heat pump and
run the fossil fuel heat.
Raising setpoint manually or by a schedule change does
not cause droop to run the backup heat. When droop is set
to other than comfort, the upstage timer setting is also
available.
Upstage Timer
The upstage timer setting is only available when:
The thermostat is configured for a heat pump with an aux
heat stage (electric of fossil fuel).
The droop setting is set to a setting other than "Comfort"
(2 °F to 15 °F).
38
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