J&R MANUFACTURING 700E, Operation And Service Manual

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P
ROCEDURE
(a) Proceed as in problem 1, if the combustion damper and exit
flue are not opening.
(b) Verify that the exit flue is clean.
(a) If the problem still exists, make sure that the two large
bypass dampers are sealing against their respective gasketed
seats. A problem with these dampers could affect the pit
temperature, but it would not explain a smoke leakage
problem.
(d) If none of the above problems is evident, then there is
insufficient combustion air for the firebox.
3). P
ROBLEM
Excessive smoke emissions from the oven doors when they
are
open.
C
AUSES
One of the following:
(a) rear bypass dampers are not opening,
(b) negative air pressure in room (usually caused by exhaust
fans), or
(c) insufficient make-up air.
S
OLUTION
(a) Open the access door to the flues and dampers. Inspect the
bypass dampers for proper operation. They should both open
when the front doors are opened.
(b) If they do not open with the front doors, inspect the linkages at the rear
of the pit. On older pits a long actuating arm connects the rear damper
linkages with another linkage above one of the front doors. This front linkage is
attached to the pivot shaft of the front door on the firebox side of the oven. The
front linkage can be inspected by removing the instrument panel at the front of
the pit. It may be necessary to remove one of the skin sections from the top of
the pit to repair a front linkage problem. On newer pits, there is a damper
motor that moves the rear damper linkages to open and close the dampers.
This motor actuates to open the dampers when the front doors open, or when
the “Evac” switch is turned on. If the dampers do not open check the linkages,
then check the damper motor, then check the door limit switch and the “Evac”
switch.
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