Operation, Auto-changeover, Two-stage operation – Carrier AQUAZONE 50QE900-250FS User Manual

Page 4: Clock backup, Fan operation, Emergency heat, Holiday mode, Dry contact switch, Remote temperature sensor

Table 1 — Daily Schedule Planner

NOTE: The cooling temperature set point must be higher than the heating temperature set point.

OPERATION

The Mode button selects the operating mode of the thermo-

stat. If OFF is selected, the thermostat will not enter Heating or
Cooling mode. If HEAT is selected, the thermostat will only
enter Heating mode (if the room temperature is below the heat-
ing set point). If COOL is selected, the thermostat will only en-
ter Cooling mode (if the room temperature is above the cooling
set point). If AUTO is selected, the thermostat will enter Heat-
ing or Cooling mode based on the room temperature and the
heating and cooling set points. If PROGRAM ON is selected,
the stored schedule is enabled and the thermostat will follow
the Occupied and Unoccupied schedules stored in its memory.

Auto-Changeover —

When the thermostat mode is set

to AUTO, the thermostat will provide automatic changeover
from Heating to Cooling mode and Cooling to Heating mode
when required. The thermostat will automatically switch to
maintain the desired temperature setting. The thermostat does
not need to be manually changed from heating to cooling or
cooling to heating operation.

Two-Stage Operation —

The second stage of heat or

cool is turned on when the first stage has been on for a mini-
mum of 2 minutes and the temperature differential from the set
point is equal to or greater than the set point plus the deadband
plus 2 degrees.

Clock Backup —

In the event of a power loss, the thermo-

stat will keep time for a minimum of 48 hours without
external power or batteries.

Fan Operation —

If Fan On is selected, the fan will run

continuously during occupied schedule (except when Mode is
switched to OFF). The fan will be off during unoccupied
schedule except during heating or cooling operation.

If Fan On is not selected, the fan will only operate during

heating or cooling operation.

Emergency Heat —

Emergency heat is available for

heat pump applications. To turn on emergency heat, press and
hold the Override button. While holding the Override button,
press the UP ARROW button. An ‘‘EH’’ will be displayed.
During emergency heat, the fan will operate and the second
stage of heat will be energized (locking out the first stage com-
pressor). To exit emergency heat, press and hold the Override
button. While holding the Override button, press the UP
ARROW button. During emergency heat, only OFF and HEAT
modes are available.

Holiday Mode —

When the thermostat is in Holiday

mode, the thermostat will operate under Unoccupied set points.
To configure and activate the Holiday mode, press the Mode
and UP ARROW buttons simultaneously to enter Program-
ming mode. Press the Override button to enter Holiday Pro-
gramming mode. The ‘‘HOL’’ icon will be displayed along
with the remaining days of Holiday mode operation. Press the
UP or DOWN ARROWS to select the number of days that the
holiday schedule will be in effect. A value of 0 disables Holi-
day mode. The duration can be set from 1 to 99 days. The ther-
mostat will enter Holiday mode on midnight of the next day
after the mode has been activated. Holiday mode will remain in
effect until midnight of the last configured day.

If the Holiday mode is in effect, the number of days remain-

ing will blink on and off and the ‘‘Unoccupied’’ icon will be
displayed. The Override button will be active during Holiday
mode. The Dry Contact Switch is ignored.

To turn off the Holiday mode before the remaining config-

ured days have passed, press the Mode and UP ARROW
buttons simultaneously for 2 seconds to enter Programming
Mode. Press the Override button to enter Holiday Program-
ming mode. Press the DOWN ARROW to set the number of
days to zero. Holiday mode will be disabled.

Dry Contact Switch —

A dry contact switch is provided

to allow an external device to force the thermostat into Occu-
pied 1. When the thermostat is forced into Occupied 1 via
the dry contact closure, the Occupied 1 icon will blink each
second.
SOFT START — When multiple thermostats are controlled
by the same external device, a Soft Start option can be used to
stagger the turn on times of the HVAC equipment. This feature
may cause a delay in operation after entering Occupied 1.

Remote Temperature Sensor —

A remote tempera-

ture sensor is available to read the temperature from a space. If
a remote temperature sensor is connected and the thermostat is
configured to use a remote temperature sensor, then the ther-
mostat will ignore the reading of its internal sensor and control
to the reading of the remote temperature sensor. When the
thermostat is using a reading from a remote sensor, the degree
symbol above the temperature reading will blink.
NOTE: This feature is configured by the installer.

DAY OF

THE WEEK

SCHEDULE

Occupied 1

Occupied 2

Occupied 3

Unoccupied

Start / Stop / Heat / Cool

Monday

Tuesday

Wednesday

Thursday

Friday

Saturday

Sunday