Johnson Controls PREMIUM EFFICIENCY VPCS Series, Installation, Operation And Maintenance Manual

Page: 28 / 56

28
FORM 145.18-IOM2
ISSUE DATE: 06/17/2020
SECTION 1 - INSTALLATION
TOP MOUNTED FRESH AIR INTAKE
The optional fresh air intake provides a 4-inch round
duct connection on top of the unit (see Figure 23 on
page 31
for right and left hand version). The fresh
air is discharged upstream of the direct expansion (DX)
coil through the discharge collector box.
Do not allow incoming air to bypass the
DX coil, otherwise, damage to the unit
may occur.
Units can be selected with the fresh air opening located
on the top left or right hand side for ease of installation.
It is recommended that applications requiring 10% or
more outdoor air utilize a pressurized fresh air system.
Unit cabinet static pressure at the RA opening is not
designed to draw 10% or more in passive fresh air sys-
tems.
The fresh air duct inside the unit is insulated to protect
the unit from condensation in the event of high humid-
ity air. However excessively moist fresh air over pro-
longed periods can result in condensate inside unit or
closet.
To avoid condensate developing inside
ducts and equipment, it is recommended
to pretreat fresh air with a high humidity
ratio before it enters the unit assembly
through ERVs or make-up air units.
The unit comes with a 4-1/4 inch RA sleeve. Front
supply openings come with a 4-1/4 inch supply plaster
flange.
Top Mounted Fresh Air Intake with Motorized
Damper
This include the same features as the top mounted fresh
air intake option with the addition of a motorized damp-
er assembly inside the discharge collector box similar
(see
Figure 23 on page 31
).
The damper assembly can be easily removed for ser-
vicing (see
Removing the Actuator on page 28
). The
motorized damper assembly opens during FAN ON op-
eration. See Figure 31 on page 49 and Figure 32 on
page 50 for the electrical schematic. For other control
options, please contact the factory.
During transportation, handling or instal-
lation of the cabinet, excessive handling
can cause an inner black plastic cover to
come loose and jam the actuator, prevent-
ing the damper from opening.
During start-up, check that the damper is opening when
the unit fan is running. It can take 20 seconds to fully
open. If the damper opens, the unit is operating as in-
tended. If the damper fails to open, the cause is likely a
loose cover preventing actuator from rotating. Remove
the actuator to service the damper.
Removing the Actuator
1. Remove the damper plate:
a. Look underneath the top of the RA flange to
notice the damper assembly.
b. Remove the seven fasteners holding the
damper plate (see Figure 19 on page 28 ) .
c. Drop the plate and disconnect the quick-con-
nect terminals from the harness.
2. Remove the red cover from the actuator body (see
Figure 20 on page 28
).
LD23557
FIGURE 19 - DAMPER PLATE FASTENERS AND
LD23558
FIGURE 20 - REMOVE THE RED COVER