Unified Brands VENTILATION SYSTEMS - Manual (Page 23)

20
To adjust air intake slot, turn nuts to loosen,
move air adjustment baffles up or down until
the desired slot opening is obtained, and tighten
nuts.
E. Fire Dampers
1. Fusible Link Type
Some ducts are protected by fire dampers
which are activated by a fusible link rated at
360
oF exhaust and 286oF supply When this
temperature is exceeded, the fusible link
melts allowing the fire damper to fall closed.
This linkage should be inspected and the
fusible links replaced annually. Fusible links
in the exhaust duct collar are readily
accessible by removing the baffle filters
[Models AF] or grease extractor modules
[Models AX]. [Refer to fig. 20 and 24] An
access plate is provided for access [supply]
duct collar for all models.
fig. 24
Electro-Mechanical Type [Refer to fig. 24]
Some ducts are protected by fire dampers
which are activated by heat sensitive
thermoswitches located near the duct inlet.
These
switches close electrically at
temperatures above 300 o F and activate a
solenoid which releases the damper, and
energizes a relay which activates the plenum
auto wash/fire extinguishing spray and
deactivates the fan. In the event of a loss of
power, the damper assembly also contains a
fusible link, set at 360
oF.
The damper can be manually closed by
pulling down on the red knob at the end of the
damper reset arm and allowing it to swing
away from the plenum.
If the damper has been activated by
excessive temperature, it cannot be reset
until the temperature has dropped below 300
o
F. After the temperature has dropped below
300
oF, the damper can be reset and opened
by pushing the damper reset arm toward the
plenum until it latches.
If the fusible link has melted, it must be
replaced before the damper can be reset. An
access plate is provided.
When the damper is closed manually or if the
fusible link melts and causes the damper to
close, the fan and auto wash down are not
affected.
When the damper closes due to activation of
the thermoswitch, the fan[s] will shut OFF and
the auto wash will actuate.
F. Air Make-Up [Supply] Plenums
Ventilators may be supplied with four [4]
different Air-Make-up plenums.
Air is
controlled by grill registers or a special E-Z
Breeze perforated panel.
1. Grill Registers [Refer to fig. 25]
Grill registers are located for external
discharge or both internal and external
discharge. Internal register have fixed
louvers for proper "Short Cycle" of air.
External registers have four-way louvers for
adjusting direction of air flow to suit job
requirements. Grill registers have opposing
blade dampers located on the rear of the
register. The airflow may be adjusted by
turning the damper adjustment screwhead
located just behind the louvers as shown in
fig. 25.
fig. 25
2. E-Z Breeze [Refer to fig. 26]
The E-Z Breeze plenum is specially designed
to slow the velocity of the supply air to
minimize the energy costs incurred for
tempering the air. The front perforated panel
is removable for cleaning. Screws are
provided to secure the panel in place after
cleaning.
FIRE DAMPER