26
Control Box
Some V3 units include an external control
box that must be mounted in the field. The
control box is designed with two mounting
holes on the back panel. Make sure the wall
fasteners can hold the weight of the control
box. See Figure 12.
Figure 12 - Back View External Control
Box
Duct Connection
Attach duct to flanges provided on the unit.
The installer is responsible for sealing ducts
to the flanges to prevent water leaks.
See Figure 5 for return and supply air duct
locations. Ductwork should be sized in
accordance with the ASHRAE Handbook.
Ductwork should be installed in accordance
with NFPA Standard 90A.
When attaching duct to the unit, use a
flexible/compressible material rated for duct
connections. A three inch flexible connector
for both return and supply duct connections
is recommended.
On units with gas heaters, a supply air
temperature sensor must be mounted in the
supply air duct at least 5 feet but less than
20 feet downstream of the furnace discharge
to limit the maximum discharge air
temperature. If possible, locate the sensor
after a turn in the duct for better air mixing.
Condensate Drain Piping
A p-trap and drain line must be installed on
the drain connection, with the p-trap not to
exceed 6” from the drain connection. The
lines should be the same pipe size or larger
than the drain connection, include a p-trap,
and pitch downward toward drain. An air
break should be used with long runs of
condensate lines.
Draw-through cooling coils will have a
negative static pressure in the drain pan area.
This will cause an un-trapped drain to back
up due to air being pulled up through the
condensate drain piping.
Condensate drain trapping and piping should
conform to all applicable governing codes.
Figure 13 - Drain Trap
Note:
The drain pan connection is a 1” MPT
fitting.
Unit should not be operated without p-
traps. Failure to install a p-traps may
result in overflow of condensate
water.
CAUTION
