Mechanical
Specifications
CAB-PRC001-EN
51
Three-Way, Two-Position Control Valves
Normally open three-way, two-position
valves are rated for a maximum 25 psig
(207 kPa) pressure differential across the
valve. Normally closed three-way two-
position valves are rated for a maximum
15 psig (103 kPa) pressure differential
across the valve. All 3-way valve piping
packages include a bypass line with a
balance fitting to set flow through the
bypass line. The balance fitting has a
maximum working pressure of 150 psig
(1,034 kPa). The valves are also available
with a maximum close-off pressure of 50
psig (345 kPa). The valve actuator is easily
removable for service without removing
the valve body from piping.
Modulating Control Valves
Two-way and three-way modulating
valves are rated for a maximum 50 psig
(345 kPa) pressure differential across the
valve. Modulating valves are available in
Cv values of 0.7, 1.5, 2.5 and 4.0.
All two-position and modulating control
valves have a maximum working
pressure of 300 psig (2,069 kPa). The
maximum entering water temperature of
the valve is 200 F (93 C).
Electric Heat Coil
Electric heating coils are available as the
total source of heating on all Force-Flo™
cabinet heaters except inverted models.
The electric heat coils are Nichrome
elements with an open-wire design.
Single stage coils are available on all
units and two-stage coils are available on
units with a Tracer ZN.520 controller. The
electric heat operates at the same voltage
as the unit. Therefore, only a single-point
power connection is necessary.
All standard electric heat coils are UL
listed and interlocked with the fan motor
switch. Therefore, electric heat operation
is possible only when the fan is running. A
transformer is supplied to eliminate the
need for field installation of a step-down
transformer. A unit-mounted magnetic
contactor is supplied on all voltages. A
high temperature cutout with automatic
reset is provided as an integral part of the
elements to de-energize the electric heat
in the event of an overheat condition.
Filters
Filters are concealed from sight and
easily removable. Filters are located
behind an integral access door on
horizontal type units. Filters are either 1”
(25 mm) throwaway or 1”(25 mm)
pleated media throwaway. Pleated media
filters are Farr 30/30.
Fresh Air Damper
A fresh air opening with damper is a
factory-installed option. Dampers are
constructed of 18-gauge steel. Fresh air is
sealed off with gasket material when the
damper is set in the closed position.
Return and fresh air mixes when the
damper is open.
Manual Damper
The manual damper is field-adjustable to
allow zero to 100 percent fresh air. The
automatic two-position damper is
accompanied by a factory-installed and
wired two-position (spring-return)
actuator.
Auto Two-Position Damper
The auto two-position damper is factory
set at 25 percent when open. The damper
can be set in the field to allow from zero
to 50 percent fresh air.
