Installation, Operation and Maintenance Manual
VariCool EZ-Fit
23
Subject to change without notice.
Supply Air Temperature Sensor
The duct mounted supply air temperature sensor is a factory
supplied, field installed, shipped loose item The supply air
temp sensor should be placed in the plenum in the middle
towards the top end to achieve the best reading for the supply
temperature This will help to ensure that the controller gets
accurate and reliable information The supply temp sensor
must be placed in a main branch or plenum Placement in
another location will result in inaccurate control
Static Pressure Transducer
The duct mounted supply air static pressure transducer is
a factory supplied, field installed, shipped loose item for a
multi-zone VAV application The static pressure transducer is
polarity sensitive Miswiring this sensor will destroy the input
on the controller! Traditionally, the static pressure transducer
should be placed 2/3 down the main duct trunk It should
be away from any turning vanes, VAV boxes, reducers, in
duct heaters, turns, bends, and transitions The sensor may
be placed closer to the supply as long as low turbulence
condition exists
Sequence of Operation Manuals
Single-Zone Variable Air Volume
Multi-Zone Variable Air Volume
Constant Air Volume
Return Air Temperature Sensor
The duct mounted return air temperature sensor is a factory
supplied, field installed, shipped loose item The return air
temp sensor should be placed in an area that can properly
average all of the return air, preferably right before the filters
if possible For maintenance room plenum applications,
the return sensor should not be placed anywhere that can
be influenced by outside sourced temperatures Common
items influencing the return temperature sensor are large
transformers, computers, control panels, doorways, outside
air dampers, water heaters, sinks and washbasins, etc
INFORMATION
If there are 2 equal duct takeoffs acting
as 2 supply mains off of the unit, the duct
static pressure transducer will not control
properly, if placed 2/3 down one of the
takeoffs Either a long enough run of main
supply before the split must contain the
static pressure sensor, or an additional
duct static pressure transducer will be
required and the positive pressure input
must be split and shared to each side to
average the two static pressures Contact
the factory
BMS Applications
The EZ-Fit unit is equipped with a Marvel Premium controller
and BACnet MS/TP (field convertible to IP/Ethernet) Refer
to the Marvel Premium installation instructions for BMS
integration
United CoolAir provides the latest versions of BACNet®
There have been installations where the legacy BAS
cannot communicate forward to the current version Any
communication issues that arise due to legacy BAS/BMS
not communicating to current protocols will be a controls
issue to be resolved by the field United CoolAir, as an OEM,
uses the current software and is not responsible for any
conversion software installed
Summary of Contents for VariCool EZ-Fit Series
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