spray mode until it is switched to either
the OFF switch or the BAKE switch is
pushed. The SPRAY mode provides 120
volt to the PLC, which in turn supplies
120 volt to starter SM2 and the
temperature controller in the remote
control panel. SM2 is present for
controlling an exhaust motor. As soon as
SM2 is energized, 120 v power is
supplied to SM1 through the PLC after a
timed delay. SM1 is provided for
controlling the motor contained within
the air make up unit and a timed delay
will still be present to delay start up.
SM1 allows 120 volt power to be
supplied to the green light for the supply
motor and the burner thru the PLC. Both
are located on the remote control panel.
When the burner switch is set to the
winter position, 120 volt power is
provided to the PLC, which supplies 120
volt power to the gas train power circuit.
When the burner switch is in the summer
position the gas train power circuit will
not be energized in the SPRAY mode.
Bake
( Models 99270 )
With the OFF switch on and the SPRAY
switch on Placing the BAKE switch in
BAKE provides 120 volt power through
the PLC internal bake timer. For the
99270 deluxe model the bake timer is
located on the face of the remote panel.
The BAKE switch supplies 120 volt
power to the PLC in the main control
panel, which begins the delay cycle. The
purge timer should be set for a minimum
of 3 minutes. At the completion of the
delay cycle, 120 volt power is supplied
to the change over damper solenoid. In
turn, the change over damper is opened
pneumatically releasing the damper air
valve. When the damper valve is
released, the change over damper
solenoid is energized, the compressed air
solenoid is de-energized. The lighting
circuit is also removed from 120 volt
supply. This drops out the lighting and
compressed air source for spray. The
PLC supplies 120 volt power to the gas
train power circuit.
In bake the PLC places the temperature
controller in the second set point or 2SP.
This is the bake mode setting.
At the end of the programmed bake time,
whether 1 or 999 minutes, the PLC
initiates the shut down mode.
Shut Down
The bake timer initiates the timed shut
down mode. The supply to the change
over solenoid is also restablished. The
change over damper closes. The lights
come back on and the temperature
controller returns to the first set position,
SP. If burner switch is in the summer
position, the PLC will shut off the gas
train circuit.
At the end of the timed cool down cycle
(1 to 10 minutes), all functions of the
unit will shut down completely, with the
exception of the lights. The PLC
interrupts the 120 volt power to the
exhaust fan, the intake fan and the
burner circuit. The lights in the booth
will remain “on” until switched off. The
PLC will hold the unit in the “off” status
until the power is interrupted to the
system by pushing the OFF switch to
“off” and back “on”.
Bake
( Models 99273 and 99275 )
8
Summary of Contents for 99270
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