Carrier WeatherMaker 48TC Series Product Data page 7

FACTORY OPTIONS AND/OR ACCESSORIES (cont.)
Opt. Humidi- - MiZer Adap. Dehum. Sys. (cont.)
This system expands the envelope of operation of
Carrier's WeatherMaker rooftop products to provide
unprecedented flexibility to meet year round comfort
conditions.
The Humidi- - MiZer adaptive dehumidification system has
the industry's only dual dehumidification mode setting.
The Humidi- - MiZer system includes two new modes of
operation.
The WeatherMaker 48TC**04- - 16 rooftop coupled with
the Humidi- - MiZer system is capable of operating in
normal design cooling mode, subcooling mode, and hot
gas reheat mode. Normal design cooling mode is when the
unit will operate under its normal sequence of operation
by cycling compressors to maintain comfort conditions.
Subcooling mode will operate to satisfy part load type
conditions when the space requires combined sensible and
a higher proportion of latent load control. Hot Gas Reheat
mode will operate when outdoor temperatures diminish
and the need for latent capacity is required for sole
humidity control. Hot Gas Reheat mode will provide
neutral air for maximum dehumidification operation.
Staged Air Volume (SAV) Indoor Fan Speed
System
Carrier's Staged Air Volume (SAV) system saves energy
and installation time by utilizing a Variable Frequency
Drive (VFD) to automatically adjust the indoor fan motor
speed in sequence with the units cooling operation. Per
ASHRAE 90.1 2010 standard section 6.4.3.10.b, during
the first stage of cooling operation the VFD will adjust the
fan motor to provide 2/3rd of the total cfm established for
the unit. When a call for the second stage of cooling is
required, the VFD will allow the total cfm for the unit
established (100%). During the heating mode the VFD
will allow total design cfm (100%) operation and during
the ventilation mode the VFD will allow operation to
2/3rd of total cfm.
Compared to single speed indoor fan motor systems,
Carrier's SAV system can save substantial energy, 25%+*,
versus single speed indoor fan motor systems.
The VFD used in Carrier's SAV system has soft start
capabilities to slowly ramp up the speeds, thus eliminating
any high inrush air volume during initial start- - up. It also
has internal over- - current protection for the fan motor and
a field installed display kit that allows adjustment and in
depth diagnostics of the VFD.
This SAV system is available on models with 2- - stage
cooling operation with electromechanical or RTU Open,
Multi Protocol controls.
conventional thermostats/controls can be used to provide
accurate control in any application.
Both space sensor and
The SAV system is very flexible for initial fan
performance set up and adjustment. The standard factory
shipped VFD is pre- - programmed to automatically stage
the fan speed between the first and second stage of
cooling. The unit fan performance static pressure and cfm
can be easily adjusted using the traditional means of
pulley adjustments. The other means to adjust the unit
static and cfm performance is to utilize the field installed
Display Kit and adjust the frequency and voltage in the
VFD to performance requirements. In either case, once set
up, the VFD will automatically adjust the speed between
the cooling stage operations
*Data based on .10 ($/kWh) in an office application
utilizing Carrier's HAP 4.6 simulation software program
Motormaster Head Pressure Controller
The Motormaster motor controller is a low ambient, head
pressure controller kit that is designed to maintain the
unit's condenser head pressure during periods of low
ambient cooling operation. This device should be used as
an alternative to economizer free
economizer usage is either not appropriate or desired. The
Motormaster will either cycle the outdoor fan motors or
operate them at reduced speed to maintain the unit
operation, depending on the model.
Winter Start Kit
The winter start kit by Carrier extends the low ambient
limit of your rooftop to 25_F (- - 4_C). The kit bypasses the
low pressure switch, preventing nuisance tripping of the
low pressure switch. Other low ambient precautions may
still be prudent.
Propane Heating
Convert your gas heat rooftop from standard natural gas
operation to propane using this field installed kit.
High Altitude Heating
High altitudes have less oxygen, which means heat
exchangers need less fuel. The new gas orifices in this
field installed kit make the necessary adjustment for high
altitude applications. They restore the optimal fuel to air
mixture and maintain healthy combustion at altitudes
above 2000 ft (610m). Kits may not be required in all
areas.
Hinged Access Panels
Allows access to unit's major components with
specifically designed hinged access panels. Panels are:
filter, control box, fan motor, and compressor.
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cooling when