9
Figure 6. Roof Curb Installation.
Rigging and Hoisting —
The unit should be lifted using
slings and spreader bars. The spreader bars are necessary
to prevent damaging the top of the unit’s cabinet. Make sure
that the lifting equipment is adequate for the load. Refer
to
Figure 1
for unit weights. Keep the unit in an upright
position at all times. The rigging must be located outside
the unit’s center of gravity. Refer to
Figure 1
for center
of gravity location.
For rooftop installations, remove
and discard the two supports attached beneath the
unit.
WARNING:
To avoid the risk of property damage or personal
injury, it is the rigger’s responsibility to ensure
that whatever means are used to hoist the unit
are safe and adequate.
CAUTION:
All panels must be securely in place when rigging
and hoisting.
Rooftop —
For rooftop installations (See
Figure 6
) use the
appropriate accessory roof curb and follow all instructions
included with it. Make sure the supports beneath the unit
have been removed. Locate the unit according to local
building codes and ordinances. The curb must be level
to insure proper condensate drainage.
The roof must be capable of handling the weight of the
unit. See
Figure 1
for unit weights. Reinforce the roof
if required.
WARNING:
Do not place combustible material on or against
the unit cabinet. Do not place combustible
materials, including gasoline and any other
fl ammable vapors and liquids, in the vicinity of
the unit.
Figure 5. Ground Level Installation.
AIR SUPPLY FOR COMBUSTION AND
VENTILATION
Provisions must be made in the installation of this unit
to provide an adequate supply of air for combustion.
Detailed instructions for determining the adequacy of
an installation can be found in the current revision of the
National Fuel Gas Code (ANSI Z223.1) and NFPA 54, or
in Canadian installation codes (CAN/CGA-B149), or in
applicable local building codes. Consult local codes for
special requirements.
WARNING:
Installation using methods other than those
described in the following sections must comply
with the National Fuel Gas Code and all applicable
local codes to provide suffi cient combustion air
for the furnace.
If the unit is operated with inadequate combustion air supply
the fl ame roll-out control located above the burners will
open, turning off the gas supply to the burners. The fl ame
roll-out control is a manually re-setable device. DO NOT
install a jumper wire across this control to defeat its function.
DO NOT reset the control without identifying and correcting
the fault condition which caused the control to trip. If this
control must be replaced, use only the replacement part
specifi ed in the Replacement Parts List.
Air Openings in the door of the unit, warm air registers,
and return air grilles must not be restricted.
To maximize heat exchanger life, the combustion air
must be free of chemical contaminants which form
corrosive acidic compounds when combusted. Some
examples of these chemical contaminants are chlorine,
fl uorine, and sulphur. Some common sources of these
2"
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