Daikin ComfortNet DX7TC Service Instructions Manual page 31

PRODUCT DESIGN
The MBVC blower cabinets use a variable speed motor that
maintains a constant airflow with a higher duct static. MBVC
blower cabinets are approved for applications with cooling coils
of up to 0.8 inches W.C. external static pressure. The MBVC
models allow airflow trimming of +/-10%.
All units are constructed with R-4.2 insulation. In areas of
extreme humidity (greater than 80% consistently), insulate the
exterior of the blower with insulation having a vapor barrier
equivalent to ductwork insulation, providing local codes permit.
DVPTC Multi-Position Air Handler
DVPTC is a multi-position, variable-speed air handler used with
R-410A and are available in 2 to 5 ton sizes with optional 3 kW to
25kW electric heat kits available for field installation. The DVPTC
unit's blower design includes a variable-speed ECM motor and
is compatible with heat pumps and variable-capacity cooling
applications.
This appliance can be installed in the vertical or left horizontal
position without modification. The horizontal right and
downflow positions require product modification. This product is
designed for zero inches (0 inches) clearance; however, adequate
access for service or replacement must be considered without
removing permanent structure. This unit can be installed on a
platform when deemed necessary.
In an attic installation a secondary drain pan must be provided
by the installer and placed under the entire unit with a separate
drain line properly sloped and terminated in an area visible to
the owner. This secondary drain pan is required in the event
that there is a leak or main drain blockage. Closed cell insulation
should be applied to the drain lines in unconditioned spaces
where sweating may occur.
NOTE: DVPTC air handlers are factory-sealed to achieve a 2%
or less leakage rate at 1.0" water gauge external duct static
pressure.
Communicating Unitary Control (UC) PCB
The Communicating System Unitary Control PCB is a
microprocessor-based control for heat pump and air
conditioning condensing units with single-phase compressors
up to 5 ton capacity operating on standard residential or Delta
and Wye commercial power. The control incorporates the basic
functionality of existing defrost controls, outdoor thermostats,
contactors, compressor staging controls, short cycle controls,
line voltage monitors, Comfort Alert™ or CoreSense Module
(dependent upon which module you are using), two speed
condenser fan relays and the Active Protection component of
enabled thermostats. The control is designed to work as part of
a fully communicating HVAC system with 4 wires. The control
also supports legacy 24VAC thermostat inputs for Y1, Y2, O
and 24VAC outputs for RVS, W1, and L for non-communicating
systems. Outputs include compressor power, compressor
stage select, and outdoor fan high and outdoor fan low speed.
System inputs include high/low pressure switches, as well as
thermistor inputs for outdoor coil temperature and outdoor air
temperature.
31