Roberts Gorden Combat WHA XS Series - Manual (Page 3)

2.5 COMBUSTION AIR AND VENTING COMPONENTS
A. Vent Box: The vent box shall be of [aluminized steel] [409
stainless steel].
B. Flue Fan: Each unit shall have a factory-installed flue fan to draw
combustion gases through the heat exchanger and into the flue
venting. No unit shall be gravity vented. The flue fan shall be
internally mounted by the manufacturer. No combustion draft
inducers shall be mounted outside of heater cabinet.
C. Combustion Air: For non-separated units, the combustion
air shall be drawn into the unit's exposed burner box directly
from the heated space through openings in the access door. For
separated units, the combustion air shall be drawn from outside
the heated space into the unit's enclosed burner box through
a piece of flexible duct that terminates at an exterior cabinet
flange. Ductwork shall be run from that flange to the building
penetration.
D. Flue and Combustion Air Connections: The flue collar and
combustion air collar (if applicable) shall be located on the rear
of the unit. For Models 30 - 125, heater design shall allow for the
shifting of the venting and combustion air collars to the top of
the cabinet in the field.
2.6 AXIAL FAN
A. Fan: Each unit is supplied with one (Models 30-250) / two
(Models 300-400) axial fan(s).
B. Fan Guard: Each axial fan is covered with a fan guard. The
guard shall protect against objects ½" (12 mm) and greater in
diameter.
C. Motor: The motor shall be an open drip-proof (ODP), standard
efficiency design, wired for 120 V/ 1 Ø / 60 Hz. The motor shall
be shaded pole (SP) (Models 30 - 75) / permanent split capacitor
(PSC) (Models 100 - 400).
2.7 CONTROL SYSTEM
A. Factory Testing: The complete control system and burner
and gas manifold functions shall be factory tested for proper
operation and to simplify field commissioning.
B. Control Enclosure: Burner controls (transformer, ignition
module, gas valve, safety switches) shall be internally
mounted by the manufacturer. No burner controls or gas train
components shall be mounted outside of heater cabinet.
C. Safety Controls:
1. Air Flow Switch: The air flow switch measures air pressure
differential across the heat exchangers to verify blower
operation and the presence of an adequate supply of
combustion air. The gas valve cannot open until the air flow
switch is satisfied.
2. High Temperature Limit Switch: The high temperature limit
switch shall turn the burners off when air is discharged above
its set point. The switch ensures unit shut down in case of
axial fan failure or any problem which may result in
overheating.
D. Controls System: Units shall be equipped for use with 120 V /
1 Ø / 60 Hz power supply. All units shall be factory equipped
with a 24 V thermostat control terminal strip on the outside of
the cabinet, pre-wired to heater internal controls. Thermostat
control terminal shall allow for 2-wire heating control or 4-wire
heating and “fan only” control.
2.8 OPTIONS AVAILABLE
(Select Applicable Options)
A. Shelf-Mounting Bracket Kit (Available for Models 30-125 Only):
The shelf-mounting bracket kit shall provide a manner in which
to mount a unit to an existing shelf.
B. Wall Suspension Mounting Bracket Kit (Available for Models
30-125 Only): The wall suspension mounting bracket kit shall
provide a wall-mounted structure from which a unit can be
suspended.
C. Wall Shelf Mounting Bracket Kit (Available for Models 30-125
Only): The wall shelf mounting bracket kit shall provide a wall-
mounted shelf structure on which a unit can be mounted.
D. Vertical Louver Kit (Available for Models 30-125 Only): The
vertical louver kit shall provide a means to control horizontal air
flow.
E. Concentric Vent Kit: The concentric vent kit allows the flue
and combustion air to be consolidated into a single concentric
vent, thereby minimizing the number of required wall/roof
penetrations. The kit consists of a concentric vent box, a 4" (101
mm)vent terminal with baffle plate and a 6" (152 mm) (Models
30-250) / 8" (203 mm) (Models 300-400) combustion air
terminal.
F. Fuel Conversion Kit: The fuel conversion kit allows for
field-conversion of the type of gas supplied to the unit. The
kit consists of a replacement spring for the gas valve and
replacement orifices.
2.9 PERFORMANCE
A. See Schedule on plans.