shut down the equipment when the LAT temperature reaches its
limit. If the equipment is shut down by a LAT or HPT limit trip,
the small ’equipment on’ triangle on the display will be flashing to
indicate this condition. Continuous fan is energized during a
LAT/HPT Limit Trip. This is true for both heating and cooling. As
with earlier Comfort Zone systems, temperature set here was
temperature where actions were started. Shutdown temperature
was 20°F higher than selected temperature. Therefore a setting of
155°F on Comfort Zone I is equivalent to 175°F on Comfort Zone
II -B.
Heat pump temperature limit for shut down is fixed at 115°F and
cooling LAT temperature limit for shut down is fixed at 40°F
(down from Comfort Zone I which was 45°F.)
Fan coils vary greatly in their LAT (leaving air temperature)
because of variations in the size of their heaters and their air flow.
This makes proper selection of LAT limits difficult. A value of 50
(150 °F limit) should be adequate. After the system is in operation,
LAT can be monitored via User Interface (configuration option 31
or 32) to check actual operating temperature. For furnaces select a
value of 75°F plus the rated maximum temperature rise from the
furnace nameplate. Factory default is 50 (or 150°F).
AVAILABLE SELECTIONS:
Use UP and DOWN buttons to move between 15 and 75 in steps
of 5.
OPTION 34—USER INTERFACE ADDRESS
When 2 Comfort Zone II -B systems are connected together on the
same bus, each must have a different address. Address 01 is used
for single systems. Address 11 is selected for second User
Interface when present. Factory default is 01.
AVAILABLE SELECTIONS:
Use UP or Down buttons to alternate between 01 and 11.
OPTION 35—DISABLE ZONING
When this option is selected, all dampers go fully open and zone
1 sensor (normally User Interface itself) becomes the sensor for the
entire home or business. In effect, the zoning system disappears
and is replaced by a single thermostat. In this mode, the ZONE X
where X is the zone number is not displayed. Factory default is OF
(off), zoning enabled. This option is used to check out the system
equipment. The User Interface acts as normal thermostat.
AVAILABLE SELECTIONS:
Use UP or DOWN buttons to alternate between OF (off) and ON.
OPTION 36—SELECT HPT OR LAT SENSOR TO MONITOR
COOLING
Previously, the LAT sensor, located in the leaving air path, was
always used to monitor cooling leaving air temperature. There are
some applications where the HPT sensor, located just downstream
of the coil, is better suited to measure the cooling leaving air
temperature. This option allows the installer to make this selection.
AVAILABLE SELECTIONS:
Use UP or DOWN buttons to alternate between LA (use LAT
sensor) and HP (use HPT sensor).
OPTION 37—LAT/HPT SAFETIES
Leaving this selection ON can cause permanent damage to
HVAC equipment
This option, when ON, tells the system to ignore the LAT and HPT
temperature information. It should only be used for troubleshoot-
ing and to allow temporary operation with a failed or missing
sensor until the sensor can be replaced. Factory default is OF (off).
AVAILABLE SELECTIONS:
Use UP or DOWN buttons to alternate between OF (off) and ON.
NOTE:
ON is for temporary use only.
OPTION 38—SELECT AUTO CHANGEOVER TIME
This option selects a 5 to 30 minute time delay between heat and
cool while in auto changeover mode. System must have no demand
in current mode for selected time before changeover between
heating and cooling is allowed. Factory default is 30 minutes.
AVAILABLE SELECTIONS:
Use UP and DOWN buttons to move between 5 and 30 in steps of
5.
SYSTEM STARTUP AND CHECKOUT
Comfort Zone II -B is designed with built-in checkout capability
for both the equipment and the zoning system. Use the sequence
below for trouble free setup. When it is time to start up system for
the first time, you may want to check out the zoning system first
and the equipment second or to reverse the process, checking
equipment first and zoning system second. Either way is accept-
able.
The following sequence checks out zoning system first. If you
wish to check equipment first, proceed to Step 4 below. Then, after
equipment is operating properly, return to Steps 1, 2, and 3 to
check out zoning system.
Step 1—Enable Installer Setup Mode
Select installer setup mode at the Equipment Controller by moving
DIP switch No. 6 to the OFF position. (See Fig. 12.) This may be
done with power on or off. This mode is indicated by InSt
appearing in the User Interface clock display. In this mode
several special features are available to assist in the setup/checkout
process:
a. When a zone is selected with the NEXT ZONE button, its
damper opens fully and all other dampers close.
b. The selected zone’s temperature appears on the large
display.
c. The FAN button turns the blower ON or OFF.
d. The MODE button operates HEAT, COOL, or EHEAT for
2 minutes and then returns automatically to OFF. No
demand from the zones is needed to bring on the
equipment in installer setup mode.
Step 2—Check Damper and Sensor Operation
At the User Interface, set the mode to OFF using the MODE
Button to make sure cooling or heating outputs are not turned on.
Use the FAN button to turn on the blower by selecting ON (not
AUTO) under the fan icon. This will start the blower (if its supply
power is on). Use the NEXT ZONE button to select ZONE 1 above
the large display. This will open Zone 1 fully and close all other
zones. It will take the system 15 sec for each zone to complete this
process.
You may now physically observe the dampers to verify their
positions are correct (and check for air blowing out all Zone 1
registers only). The large display reads the temperature in Zone 1.
Use this opportunity to verify the Zone 1 sensor is properly
connected and is located in Zone 1 by breathing on the Zone 1
sensor and observing the temperature change. Remember, the
Zone 1 sensor is normally inside the User Interface but a remote
sensor may be used.
Use the NEXT ZONE button to select Zone 2 and repeat the above
process. Continue through all zones. When finished, you will have
verified that all the dampers and zone sensors are properly
connected and working.
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