Product data

H. Each Zone Damper shall include:
1. A motorized damper assembly constructed of
24 gage galvanized iron with blade of 20 gage.
2. Blade operation providing full modulation from
open to closed position.
3. The ability to operate in a master/slave arrange-
ment, where the master damper is operated by
the zone controller. The master damper shall have
the capability to have up to 3 dampers tracking its
position. The slave dampers shall modulate to the
same position as the master damper.
4. Round dampers shall have elliptical blades with a
seal around the entire damper blade edge. Rec-
tangular dampers shall have fully sealed edges.
5. A duct temperature sensorshall bean integralpart
of the damper assembly.
2.02 SEQUENCE OF OPERATION
The VVTt System shall control the HVAC units in
the following manner:
A. The VVT monitor thermostat shall determine the de-
mand for heating or cooling based on the number of
zones calling or the greatest demand for a particular
mode. The VVT monitor thermostat will establish the
zonewith thegreatest demandasthe ReferenceZone.
B. The VVT monitor thermostat shall communicate with
its zone controllers and bypass controller on a com-
munication bus network.
C. The VVT monitor thermostat shall access zone de-
mand for heating and cooling from each zone slave
thermostat and use this information to control the
HVAC unit based on zone demand.
D. When any thermostat senses a temperature deviation
of 1.5° F or more from its current set point, it be-
comes a zone heating or cooling caller. When a zone
becomes a caller, the monitor thermostat registers its
demand and its heating or cooling caller status. When
the monitor thermostat registers the minimum re-
quired number of zone callers, as determined by the
system mode demand, a mode is selected. The mode
selected shall meet all lockout temperature criteria (if
applicable).The monitorthermostatshall energize that
specific mode.
E. On a rise to 2° F the monitor thermostat shall ener-
gize second stage if the temperature trending pro-
gram allows second stage operation. When demand
falls to 1.0° F, the second stage is released. When de-
mand falls to 0.5° F, the first stage is released.
F. The monitor thermostat shall hold the system mode
until the Reference Zone is within .5°F of its set point
or until the system mode reselect time limit has ex-
pired and the system demand is such that the moni-
tor thermostat selects the opposite mode.
G. The bypass controller shall pre-position its damp-
er(s) to the maximum open position prior to system
start-up. The bypass controller shall regulate pressure
from minimum system pressure during start-up to
maximum system pressure during normal operating
conditions. The bypass controller shall monitor
supply- air temperature. During changeover mode,
the bypass controller shall open the bypass dampers
to pre-condition the supply air if it is needed by the
Reference Zone.
H. The individual zone controllers shall be capable of
operating in the ventilation mode until the zone be-
comes 1.5° F out of set point in either direction. At
this point the zone controller shall request the appro-
priate mode from the monitor thermostat.
2.03 SOFTWARE
A. Access capability to the system, whether local or re-
mote, shall be accomplished using the CarrierSystem
Software.Softwareaccess shall notrequireanychanges
or modifications to the VVT control devices or asso-
ciated system sensors.
B. The software shall be capable of, but not limited to:
listing all current system sensor readings, listing and
modifying configuration parameters such as occu-
pancy schedules, set points, alarm options, and tem-
perature limits.
C. The software shall be capable of providing levels of
access into the system from simple monitoring to full
monitoring and modifying system configurations for
all components.
2.04 SERVICE AND WARRANTY
A. After installation, system start-up shall be completed.
All thermostats and related components will be ad-
justed. The equipment being controlled by the speci-
fied control system shall be in operation and fully
checked. The entire system must be in operation for
24hours priorto seeking acceptancefrom theowner/
engineer.
B. The control system herein specified shall be free from
defects in workmanship and material under nor-
mal use and service. If, within 12 months from date
of acceptance by owner/engineer, any of the equip-
ment herein described is proved to be defective
in workmanship or material, it will be repaired, ad-
justed, or replaced free of charge by the installing
contractor.
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