Ecobee SMART Installation Manual page 13

Min Cycle Off Time Enables you to configure the
compressor off time between cycles. This is adjustable
from 240 - 900 Seconds.
Min Outdoor Temp Allows you to set the minimum
outside air temperature at which the compressor will
be disabled. This performs two functions: You can set
it to prevent the compressor from going on when
the outdoor temperature is too low, thus resulting in
damage to the compressor. You can also set this value to
determine when you want the auxiliary heat (if installed)
to engage to help meet the set temperature. The
temperature range is adjustable from 0°F (-17.8°C) - 65°F
(18.3°C) or can be completely disabled. You will need an
internet connection for this feature to operate properly.
Allow Heat Pump/Auxiliary Heat to Run Simultaneously
If you select Yes and there is a source of auxiliary
heat, it will turn on in addition to the heat pump. The
heat pump will be energized for the first 30 minutes.
If, after 30 minutes, the set point has not been met,
the auxiliary heat will be energized to assist the heat
pump in meeting the load.
If you select no, the heat pump will be energized for up
to 2 hours. If after 2 hours the set point has not been
met, the Thermostat will shutdown the heat pump and
energize the auxiliary heat to meet the set point. This
option should also be used for installation where the
heat pump evaporator coil is downstream from the
source of auxiliary heat.
Furnace (Auxiliary Heat)
Allows you to enable and configure up to a 3-stage
conventional heat source. If you have selected Heat
pump as your primary source, this feature will allow you
to configure the auxiliary heat connected to the system.
Furnace Type Allows you to configure the type of fur-
nace connected. This allows the Smart Thermostat to
optimize its algorithms based on the type of fuel and
typical characteristics of the chosen system. Choose
the option that best represents the type of heating
system installed.
21 Configuring The Smart Thermostat
Heat Stages Allows you to configure up to 3 stages of
heat. If you require a third stage, you must configure
an accessory relay to control that stage.
Heat Fan Control This option allows you to determine
if the system fan is controlled by the system during
heat cycles, or if the Thermostat is required to control
the fan. Normally the HVAC system controls the fan
during heat cycles.
Air Conditioner
Allows you to enable and configure up to 2 stages of air
conditioning. If you require a second stage, you must
configure an accessory relay to control that stage.
Staging Method of Operation
The ecobee Smart Thermostat uses a unique method
for staging for multi-stage heating or cooling. It uses
a combination of intelligent algorithms and past
performance to determine when to activate the stages.
When there is a call for heat or cool, the system computes
how long it would take for the system to reach the desired
set point in stage 1, stage 2 or stage 3 accordingly. It will
determine the highest stage at which a minimum of 10
minutes of run time is required. It will then automatically
start the system at that stage (ie if it calculates that it will
take 15 minutes at stage 2 but only 7 minutes at stage 3,
the system will immediately turn on stage 2 to meet the
set point). If the calculation indicates to start at stage 1,
and it takes more than 10 minutes to reach the set point,
it will automatically engage stage 2. If stage 2 runs for
more than 10 minute without reaching the set point it will
activate stage 3. A minimum run time of 10 minutes is used
to ensure that proper circulation throughout the system
and that minimum cycle times are maintained. For heat
pumps with auxiliary heat, the operation of the auxiliary
heat will depend on the configuration of the Allow Heat
Pump/Auxiliary Heat to Run Simultaneously.
Accessory relays
Accessory relays are generic relays that can be configured
to control the following;
Heat Stage 3 Select this option when the Thermostat
is required to control a 3-stage conventional heating
system. Connect the third stage (or W3) contact to this
accessory relay.
Configuring The Smart Thermostat 22