Product data

21
Monitor thermostat configuration — The monitor
thermostat controls the operation of its own zone and of
each associated zone controller. The monitor thermostat
determines system operation from the information re-
ceived from each device that it controls. The monitor ther-
mostat must be configured for proper control of the
system. Part of the configuration is Category 4.0, which
deals with HVAC settings. The Category 4.0 HVAC Equip-
ment table shows the default settings for this category.
NOTE: In the majority of cases only categories 4.5, 4.6,
4.7, 4.8 and 4.15 will require changing by the installer.
Leaving-air temperature (LAT) monitoring must be al-
ways used. This function prevents the HVAC equipment
from operating in a range that will cause equipment safety
trips, leading to shortened equipment life.
There are tradeoffs involved in the selection of the sys-
tem mode demand, monitor thermostat configurations
4.15. Lower setting levels tend to improve comfort but
tend to increase operating costs and reduce equipment re-
liability. Buildings that have large core areas that are likely
to make a call when others are not should use lower system
mode demand levels. For buildings with zones that have
more similar load patterns from zone to zone, or smaller
zones or more uniformly sized zones, a higher setting
should be used.
CATEGORY 4.0 HVAC EQUIPMENT —
DEFAULT SETTINGS
DX coil sensor installation — The use of a DX (direct
expansion) coil sensor is recommended. The DX tempera-
ture sensor should be installed in the ductwork as close to
the equipment as possible. Care must be taken not to have
the sensor within “line of sight” of the equipment’s heating
elements. Radiation from the heat can cause the sensor to
read an elevated reading.
The majority of the units referred to by these application
guidelines are two compressor units. The monitor thermo-
stat has the ability to read only one DX coil sensor, which
can only be installed within the equipment on a single com-
pressor unit. All of the LAT settings have been determined
assuming supply duct temperatures versus coil tempera-
tures. Be sure the DX coil sensor option is turned on.
Category 5.6 under the monitor configurations, should be
ON.
Application guidelines — The units are constant vol-
ume units and will require the use a bypass damper and
controller. Refer to page 19 for details regarding the use
and installation of the bypass damper.
These units use a TXV metering device. Use of optional,
factory-installed hot gas bypass (HGBP) is recommended
for VVT® applications to aid in low load performance
operation.
Electrical connection from the VVT system to the units
will be the typical thermostat connections from the relay
pack to the unit.
Carrier Apollo controls
The Apollo direct digital controls are ordered as a factory-
installed option. Designed and manufactured exclusively by
Carrier, the controls can be used to actively monitor and
control all modes of operation, as well as to monitor
evaporator-fan status, filter status, indoor-air quality (hu-
midity and carbon dioxide), supply-air temperature,
outdoor-air temperature, and field-provided sensors.
The Apollo communicating controls are factory-installed
into the rooftop unit control box, and come equipped with
built-in diagnostic capabilities. Light-emitting diodes (LEDs)
simplify troubleshooting by indicating thermostat com-
mands for both stages of heating and cooling, evaporator
fan operation, and economizer operation. The Apollo
communicating controls are designed to work specifically
with the Carrier TEMP and VVT® (variable volume and
temperature) thermostats. The Apollo controls allow the
use of an IAQ (Indoor-Air Quality) sensor. The Apollo con-
trols, combined with Carrier thermostats, incorporate a
5-minute recycle delay timer between modes of operation
to prevent short cycling.
The standard rooftop control system is readily adaptable
to all conventional and programmable thermostats. In addi-
tion, units are suitable for integration into building monitor
control systems if required. This system gives the units the
flexibility to communicate with almost any thermostat or
building control system.
SETTING DESCRIPTION
CURRENT
DEFAULT
4.1 Fan Operation Off
4.2 Time Guard® Device between modes On
4.3 Time Guard Device Override Off
4.4 LAT Monitoring On
4.5 First Stage Cooling Limit (F) 45 F
4.6 Second Stage Cooling Limit 50 F
4.7 First Stage Heating Limit 110 F
4.8 Second Stage Heating Limit 105 F
4.9
Auxiliary Relay (0= No Control,
1=Occupied Schedule, 2=IAQ,
3=Reversing Valve, 4=Economizer)
0
4.10 Optimize Staging On
4.11 Cooling Temperature lockout On
4.12 Cooling Lockout Set Point 45 F
4.13 Heating Temperature Lockout Off
4.14 Heating Lockout Set Point 60 F
4.15 System Mode Demand 3
4.16 System Mode Re-Select (minutes) 30
4.17 Minimum Heat Run Time 5
4.18 Minimum Cool Run Time 3
4.19 Pre-occupancy Purge Off
4.20
Fan Switch (0=Thermostat Switch Position,
1=Fan Switch On, 2=Fan Switch Off)
0
4.21
Cool Switch (0=Thermostat Switch Position,
1=Cool Switch Auto, 2=Cool Switch Off)
0
4.22
Heat Switch (0=Thermostat Switch Position,
1=Heat Switch Auto, 2=Heat Switch Off)
0