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This section is provided to assist a service technician
and explain in detail what is happening during
“normal” operation of a booth with a Touch Screen
option.
SPRAY/BAKE BOOTH OPERATION
The spray/bake booth has five separate modes of
operation: POWER ON, SPRAY, BAKE, COOL
DOWN and SHUTDOWN.
POWER ON:
The touch screen display is on when the booth is in
POWER ON mode. The 110v and 24v control
voltages are provided from the secondary side of the
control transformer. The primary side of the control
transformer is connected to the incoming three-phase
motor voltage supply.
The 120v is connected through a jumper connection
provided for use with a NC contact on an alternative
fire suppression system that requires shutdown of the
booth fans. Breaking the circuit at that point will shut
down all booth operations. The 120v continues
through the EM (emergency) stop switch in the
remote control panel, and NC overload contacts of
each Motor Starter. The 120v is then present at the
light switch, the programmable logic controller
(PLC) and the touch screen. If either motor trips to
an overload condition, a RED light on the touch
screen for the respective motor is lit, and all booth
operations quit. Breakers protect both control
voltages, 110v and 24v.
The EM switch, when depressed, shuts down all
booth operations. Turning the EM switch clockwise
reconnects the supply voltage, unless the
jumper circuit for the fire suppression system
is open.
SPRAY MODE:
When the touch screen is displayed, touching
the word SPRAY will put the controls in the
Spray Mode. The booth will operate in
SPRAY mode indefinitely until the operator
shuts off the booth, or switches to the Bake
Mode. The SPRAY mode provides 120v to
the PLC (Programmable Logic Controller) and
shows input “0” on the PLC input display.
This in turn provides 110v to starter SM2
located in the Control Panel. SM2 controls the
Exhaust Fan Motor and shows as “10” on the
PLC output display. The indicator light for the
exhaust fan motor on the Touch Screen should
be green. A time sequence is also started in the
PLC as SM2 is energized. At the end of the
time sequence, 110v power is provided to the
temperature controls and starter SM1, located
in the Control Panel. SM1 controls the Intake
Fan Motor and shows as “9” on the PLC
output display. The indicator light for the
intake fan motor on the Touch Screen should
be green. SM1 provides 120v to the burner
control circuit. The touch screen will show the
booth temperature and the controls should go
through the boot operations.
If the BURNER switch is in the WINTER
position, 120v power is provided to the PLC
and shows as “3” on the PLC input display,
which in turn provides 110v to the gas train
power circuit shown as “7” on the PLC output
display. See the text of the Gas Train Power
Circuit. If the BURNER switch is in the
SUMMER position, the Gas Train Power
Circuit will not be energized as there will be
no input to the PLC.
BAKE MODE:
Touching the word BAKE on the touch screen
begins the Bake Mode and provides 120v to
