Duct System; Electrical - Bosch SM Series Installation, Operation And Maintenance Manual

10 | Duct System

The air handler should be pitched approximately
1/4" towards the drain in both directions, to
facilitate condensate removal. See Fig. 10.
Drain Pan is not internally sloped.
Fig. 10 Air Handler Pitch
DUCT SYSTEM
A supply air outlet collar and return air duct flange
are provided on all units to facilitate duct
connections.
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.
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 duct work, a check should
be made to ensure that the duct system has the
capacity to handle the air required for the unit
application. If the duct system is too small, larger
8733826256 (2020/06)
duct work should be installed. Also, check for
existing leaks and repair.
NOTICE: Do not connect discharge ducts
directly to the blower outlet.
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 through
the return air grill 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
Fig. 13.)

ELECTRICAL

WARNING: UNIT OPERATION AND SAFETY
HAZARD
Field wiring must comply with local and
National Electric Code (NEC).
WARNING: UNIT OPERATION AND SAFETY
HAZARD
Power to the unit must be within the
operating voltage range indicated on the
unit's nameplate or on the performance
data sheet.
WARNING: UNIT OPERATION AND SAFETY
HAZARD
Properly-sized fuses or HACR circuit
breakers must be installed for branch
circuit protection. See the unit nameplate
for maximum fuse or breaker size.
NOTICE: 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.
Subject to change without prior notice
SM Split AH/AV Air Handler
SM Split AH/AV Air Handler