Subject to change without prior notice Revised 03-11
6 720 220 046
6
TA Series
duCT SYSTeM
A supply air outlet collar and return air duct flange
are provided on all units to facilitate duct
connections. Refer to the Bosch individual data
specification sheet for physical dimensions of the
collar and flange.
A flexible connector is recommended for supply and
return air duct connections on metal duct systems. All
metal ducting should be insulated with a minimum of
one inch duct insulation to avoid heat loss or gain and
prevent condensate forming during the cooling
operation. Application of the unit to uninsulated duct
work is not recommended as the unit’s performance
will be adversely affected. Do not connect discharge
ducts directly to the blower outlet. The factory
provided air filter must be removed when using a filter
back return air grill. The factory filter should be left in
place on a free return system.
If the unit will be installed in a new installation
which includes new duct work, the installation
should be designed using current ASHRAE
procedures for duct sizing. If the unit is to be
connected to existing ductwork, a check should be
made to assure that the duct system has the
capacity to handle the air required for the unit
application. If the duct system is too small, larger
ductwork should be installed. Check for existing
leaks and repair.
The duct system and all diffusers should be sized to
handle the designed air flow quietly. To maximize
sound attenuation of the unit blower, the supply
and return air plenums should be insulated. There
should be no direct straight air path thru the return
air grille into the heat pump. The return air inlet to
the heat pump must have at least one 90 degree
turn away from the space return air grille. If air
noise or excessive air flow are a problem, the
blower speed can be changed to a lower speed to
reduce air flow. (Refer to ECM motor interface
board section in this manual and Figure #7)
PIPInG
Supply and return piping must be as large as the
unit connections on the heat pump (larger on long
runs). Never use flexible hoses of a smaller inside
diameter than that of the fluid connections on the
unit. TA units are supplied with either a copper or
optional cupro-nickel condenser. Copper is
adequate for ground water that is not high in
mineral content. Should your well driller express
concern regarding the quality of the well water
available or should any known hazards exist in your
area, we recommend proper testing to assure the
well water quality is suitable for use with water
source equipment. In conditions anticipating
moderate scale formation or in brackish water a
cupro-nickel heat exchanger is recommended.
Both the supply and discharge water lines will
sweat if subjected to low water temperature. These
lines should be insulated to prevent damage from
condensation.
All manual flow valves used in the system must be
ball valves. Globe and gate valves must not be used
due to high pressure drop and poor throttling
characteristics. Never exceed the recommended
water flow rates as serious damage or erosion of
the water to refrigerant heat exchanger could
occur.
Always check carefully for water leaks and repair
appropriately. Units are equipped with female pipe
thread fittings. Consult the specification sheets for
sizes. Teflon tape sealer should be used when
connecting water piping connections to the units to
insure against leaks and possible heat exchanger
fouling. Do not overtighten the connections.
Flexible hoses should be used between the unit and
the rigid system to avoid possible vibration. Ball
valves should be installed in the supply and return
lines for unit isolation and unit water flow
balancing.
eleCTrICAl
(Refer to electrical component box layout, Figure #5)
Field wiring must comply with local and national
electric codes. Power to the unit must be within the
operating voltage range indicated on the unit
nameplate or on the performance data sheet. On
three phase units (single stage units only) phases
must be balanced within 2%.
Caution
Operation of unit on improper line voltage or with
excessive phase imbalance will be hazardous to the
unit, constitutes abuse and may void the warranty.
duct System
