Wells M4200 User Manual download pdf

The following information applies to McDonald’s® Convection Ovens Models M4200-2 thru M4200-3S

series and includes ovens with both early-style and current production solid state controllers.

A. Early units had a temperature controller (p/n 63870) with screwdriver adjustment for setting

and/or calibration, and utilized a separate timer board (p/n 63040). See page 2 for setting and

calibration instructions.

B. Current production ovens use an integrated controller/timer board (p/n 64964) with a built-in key pad

for all temperature control, calibration and timer functions. See page 3 for setting and calibration

instructions. Some common concerns:

1. There have been occasional interruptions in the newer controllers caused by random radio

frequency noise. The controller temperature will be reset to its default setting (100ºF) causing

the oven to not heat. If this happens, the controller has lost it’s memory and must be reset:

a. Unplug the power cord for 5 minutes, reconnect power cord.

b. Reset the SET temperature per page 3.

c. If the problem persists, a radio frequency interference filter is available as p/n 502021.

2. If the oven will not hold calibration within ±3º F (1º C) one possibility is that calibration was done

without allowing the oven temperature to stabilize:

a. Set-up the oven per the calibration instructions on page 3.

b. Allow at least five complete heating cycles before calibrating the oven controller.

C. Both early-style and current production ovens may experience an oven blower failure:

1. Not all failures are actually the motor itself. Often, the problem is with the capacitor rather

than the motor.

2. See page 5 for instructions on troubleshooting the motor.

3. See page 5 for an upgrade to locate the capacitor to a lower heat area. This will extend the life

of the capacitor.

WELLS MANUFACTURING COMPANY

2 ERIK CIRCLE, P.O. BOX 280

Verdi, NV. 89439

Technical Service (888) 492-2782

Service parts Fax (888) 492-2783

e-mail [email protected]

SERVICE BULLETIN

100.001

(Superseds 880-062097 &

880-061997)

TO: Wells Authorized Service Agencies Nov. 15, 2000

FROM: Hanju Lee

SUBJECT: McDonald’s Convection Oven Maintenance, Adjustment and Calibration

CAUTION: BURN HAZARD

Exposed surfaces can be hot to the

touch and may cause burns.

Page 1 of 5

1 2 3 4 5

Summary of Contents

Page 1 - CAUTION: BURN HAZARD

The following information applies to McDonald’s® Convection Ovens Models M4200-2 thru M4200-3Sseries and includes ovens with both early-style and curr

Page 2 - Figure 1

SETTING AND CALIBRATING OVEN TEMPERATURESEARLY-STYLE CONTROLS (UNITS WITH SEPARATE TIMER AND CONTROLLER)Monthly Check Calibration (Oven with screwdriv

Page 3 - CURRENT PRODUCTION CONTROLS

SET SET SETStep 6Figure 2SETTING AND CALIBRATING OVEN TEMPERATURESCURRENT PRODUCTION CONTROLSMonthly Check Calibration (Oven with keypad adjustments)

Page 4

10. Use the SET buttons located below the temperature display (Figure 2) to set thedisplayed temperature so that it is the same as the reading on the

Page 5 - BLOWER MOTOR TROUBLESHOOTING

BLOWER MOTOR TROUBLESHOOTINGSYMPTOM: The blower does not run when the ON/OFF/FAN switch is placed in the “ON” position:A. Be sure the door is closed