Despatch S Type - Manual (Page 7)

I-235 (9/03) −
4
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12.
Gas-fired heaters model number indicates capacity in BTU per hour, i.e.,
DG-350 rated at 350,000 BTU per hour
DG-500 rated at 500,000 BTU per hour
DG-750 rated at 750,000 BTU per hour
DG-1000 rated at 1,000,000 BTU per hour
DG-1500 rated at 1,500,000 BTU per hour
13.
A.F.S. indicates airflow switch. Refer to Illustration #15.
14.
A. If oven is to be mounted on wood floor, insurance requirements are such that 4" clay
building tile are required between wood floor and bottom of oven. Tile must be placed
with openings in tile in line to permit free flow of air across the short axis of the oven.
(Insulation batts for joint packing may be cut into strips with a “butcher knife” or
equivalent, using a sawing motion.)
B. It is required for ovens operating above 350°F to have an insulated floor. If the oven is
to be mounted on an existing concrete floor, a pit must be added and filled with insulating
floor material (“DES-CRETE” or other. See mixing & curing instructions on page 9).
15.
Bolted connections on structural platforms, heater box support structural, etc., are for
erection ease only. These connections should be welded after erection unless noted
otherwise on the drawings. This is especially critical at connections where fan vibration is
possible.
16.
The fresh air and exhaust damper settings should be in the closed position unless they
have been preset at the factory. Minimal adjustments to enhance certain requirements
(ie: temperature uniformity, pressure balance) can be made. Allowing too much fresh air
in can result in increased exterior wall temperatures. Opening the exhaust damper can
introduce cool air from outside the oven that can affect temperature uniformity. See
‘Damper Operation’ in the Oven Instruction Manual for additional information.
17.
If there is a variable speed drive for the recirculation fan it is important not to change the
fan speed without understanding the consequences. Pressure changes or changes in
air velocity in the heater box can be affected. Consult the factory with any questions or
concerns.
18.
As part of a preventative maintenance program all fasteners should be inspected on a
regular basis. All loose fasteners should be tightened.