Middleby Marshall PS360 F. Initial Troubleshooting, 120VAC supply. Wire colors vary by oven model

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.

Connections are

reversed if

conveyor direc- tion is reversed.

120VAC supply. Wire colors vary by oven model.

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”

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.

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