Middleby Marshall PS200 series - Manual (Page 19)

18
SECTION 3 - SERVICING COMPONENTS
F. Initial Troubleshooting
NOTE: When changing the conveyor speed on a controller
with a thumbwheel, it is advisable to turn the conveyor switch
OFF before adjusting the thumbwheel. Note that this can-
not be done on a digital keypad, as switching the conveyor
switch OFF will also turn off the display.
1. Check all connections at the terminals on the conveyor
speed control module to ensure that they are correct
and tight. Connections are shown in the drawing.
Correct the connections if necessary.
2. Ensure that there is power to the controller. Use a
digital multimeter to read the voltage between the ter-
minals marked “AC.” The voltage should read between
110-120VAC.
If the power is not present or of an incorrect voltage,
check the power source.
3. With the AC power on,
check the DC voltage to
the conveyor motor.
Match the measured volt-
age with those shown on
the chart below. If the
voltage reading is more
than ±5VDC of that shown
on the chart, complete
the Motor Test on the next
page.
Thumbwheel/ DC Motor Voltage
Display PS200, PS310, 360,
Setting 570, 360WB70 360WB, 360EWB
3 mins. 84VDC 67VDC
4 mins. 63VDC 50VDC
5 mins. 51VDC 40VDC
6 mins. 43VDC 34VDC
7 mins. 37VDC 28VDC
8 mins. 32VDC 25VDC
9 mins. 29VDC 22VDC
10 mins. 27VDC 20VDC
11 mins. 24VDC 18VDC
12 mins. 22VDC 17VDC
13 mins. 19VDC 14VDC
15 mins. 18VDC 13VDC
4. Check the magnetic
pickup on the motor.
If the pickup is in good
condition, check that
the conveyor is running
and then check the volt-
age between the “COM
and “±5VDC” terminals
on the controller. On
controllers with thumb-
wheels, the voltage
should read 5VDC,
±0.3VDC. Digital con-
trollers should read
5VDC , ±1.0VDC.
Next, check the voltage
between the “COM”
Connections are
reversed if
conveyor direc-
tion is reversed.
and “COUNT” terminals. The reading should stay be-
tween 2 and 3VDC.
If EITHER of these two readings are incorrect, perform
the Conveyor Control Pickup Test on the next page.
120VAC supply.
Wire colors vary
by oven model.