Trane BCHE Installation, Operation And Maintenance Manual page 49

Figure 39. Crossover harness installation
Duct Connections
All duct connections should be installed in accordance with
the standards of the National Fire Protection Association
(NFPA);
• Installation of Air Conditioning and Ventilation Systems
other than Residence Type (NFPA 90A)
• Residence-Type Warm Air Heating and Air
Conditioning Systems (NFPA 90B)
Make duct connections to the unit with a flexible material
such as heavy canvas to help minimize noise and vibration.
If a fire hazard exists, Trane recommends using Flexweave
1000, type FW30 or equivalent canvas. Use three inches
for the return duct and three inches for the discharge duct.
Keep the material loose to absorb fan vibration.
Run the ductwork straight from the opening for a minimum
of 1 1/2 fan diameters. Extend remaining ductwork as far as
possible without changing size or direction. Do not make
abrupt turns or transitions near the unit due to increased
noise and excessive static losses. Avoid sharp turns and
BCX-SVX002A-EN
use elbows with splitters or turning vanes to minimize static
losses.
Poorly constructed turning vanes may cause airflow
generated noise. Align the fan outlet properly with the
ductwork to decrease duct noise levels and increase fan
performance. Check total external static pressures against
fan characteristics to be sure the required airflow is
available throughout the ductwork.
To achieve maximum acoustical performance, minimize the
duct static pressure setpoint.
Mix Box Damper Linkage
1. Verify bearing bracket on back damper is biased to the
floor and the bearing bracket on the top damper is
biased to the end of unit wall.
2. Confirm the crank arms and actuator are setup
according to Figure 40, p. 50
3. Verify crank arm bolts and linkage rod set screws are
tightened.
Installation Mechanical
and Figure 41, p. 51.
49