Wells Manufacturing MDMW-3/LWC User manual

Brand: Wells Manufacturing

Model: MDMW-3/LWC

Type: User manual

This manual is also suitable for

MDMW LOW WATER SENSOR MODIFICATION KIT INSTALLATION

INSTRUCTIONS

NOTE: Installation of this kit must be done by qualified service personnel or the warranty

will be voided.

Tools Required!

Phillips screw driver Slot blade screw driver

3/8 inch nut driver 11/32 inch nut driver Razor

knife or x-acto knife

Parts List:

Heating element/high limit switch pan assembly Insulation cover/resistor

assembly Buzzer/bracket assembly Wire set wiring diagram

Instructions:

1. Remove base.

2. Remove insulation from control area and save.

3. Remove bottom insulation cover and discard.

4. Temporarily install insulation cover/resistor-assembly

5. Using the insulation cover as a template, cut rectangular hole in bottom

insulation.

6. Remove insulation cover and bottom insulation.

7. Using slot blade screwdriver, remove element clips from heater element pan.

EPC07/12/90S001-II45932 PN 45932 A

MDMM Low Mater Sensor Modification Kit Installation Instructions

8. Remove heater element pan and discard.

9. Install heater element in heater element pan/high limit switch assembly.

10. Install heater element pan/high limit switch assembly.

11. Remove the two screws attaching the convenience outlet to the control panel.

12. Place buzzer/bracket assembly between convenience outlet and control panel. Re-

install.

13. Install bottom insulation and insulation cover/ resistor assembly.

14. Remove the control knob from the thermostat.

15. Remove the 2 screws attaching the thermostat to the control panel.

16. Lift out the thermostat and remove and discard the thermostat stop (refer to Figure 1).

THERMOSTAT STOP THERMOSTAT FACE

Figure 1

17. Install the thermostat stop supplied (refer to Figure 2).

page 1

MDMW Low Mater Sensor Modification Kit Installation Instructions

18. Re-install thermostat in control panel and install knob.

NOTE: Steps 19 through 24, refer to attached wiring diagram.

19. Remove wire #4 from on/off switch and install on high limit switch

terminal # 3 (refer to Figure 3).

20. Install wire #9 between on/off switch and high limit switch terminal # 1 (refer

to Figures 3 and 4).

page 2

MDMW Low Mater Sensor Modification Kit Installation Instructions

21. Remove wire #6 from red power light (refer to Figure 5).

CAUTION: Be sure to remove wire that is connected to wire #2 at on/off switch,

otherwise buzzer will not operate.

22. Install wire #11 between buzzer and red power light Re-install wire #6 (refer to

Figures 5 and 6).

23. Install wire #12 between high limit thermostat terminal #2 and ballast resistor, and

wire #10 between high limit thermostat terminal #2 and buzzer (refer to Figures 3, 6

and 7).

Figure 7

page 3

MDMW Low Water Sensor Modification Kit page 4

Installation Instructions

24. Install wire #13 between buzzer and ballast resistor (refer to Figures 6 and 7).

55. Re-install insulation around control area.

26. Re-install base.

MDMW LOW WATER CUT OFF ADDENDUM:

ITEM PART NO.

DESCRPTION QTY. FUNCTION

20 60639 Bottom Cover Panel 1 Panel to cover electrical components at the

bottom.

21 60660

66090

Fiberglass Insulation (Sides) (Bottom) 1 Insulation to prevent heat dissipation through

sides and bottom.

22 60892 Thermostat 1 To maintain water pan temperature.

23 - Thermostat Bulb (Part of Item 22) (under

Thermostat Clamp Plate)

1 Temperature sensing part of the thermostat

24 60598 Thermostat Clamp Plate 1 Clamps thermostat bulb to the water pan.

25 65944 Heating Element Pan and Clip Assembly 1 Clips retain heating element and element

radiates heat into water pan.

26 60566 Heating Element 1 Heat source for marinator.

27 66107 Wiring Harness (Not shown) 1 Electrical distribution system for electrical

components,

28 65936 Cover, Insulation 1 Panel to retain insulation.

29 60564 Feet 1 Non-skid and raises marinator off table for

proper air circulation.

30 65939 Low water thermostat 1 Turns off heating element and turns on

buzzer when water pan is dry.

31 65943 Buzzer 1 Sounds alarm when water pan is dry.

32 65938 Buzzer bracket 1 Mounts Buzzer

33 65937 Ballast Resistor 1 Draws electrical current through buzzer

contact of low water thermostat.

34 65942 Insulator 1 Insulates Ballast Resistor terminal from

insulation cover.

35 65934 Insulation 1 Insulation to prevent heat dissipation through

bottom.

HARDWARE IDENTIFICATION

ITEM PART NO.

DESCRIPTION QTY.

F 55135 Screw, 1/4-20 x 3/8" (9 mm) SS Truss Head 16

K 51716 Washer. Flat #6 Monel Element 4

M 55313 Nut, Kep 10-32 4

N 50397 Clip, Heating element 5

Q 51053 Nut, Kep 8-32 3

R 61966 Bolt, 1/4 - 20 x 2 1/4 1

PN 46270

SH 1 OF 2

NOTE: This trouble shooting guide is in addition to trouble shooting guide in the

Marinator Equipment Manual.

PROBLEM PROBABLE CAUSE CORRECTIVE ACTION

a. Buzzer sounds.

a. No water in water pan.

a. Add water up to the mark in water

pan.

b. Buzzer sounds

water is in

b. Thermostat out of calibration. b. To calibrate follow planned Maintenance Card

61.

water pan.

c. Buzzer sounds

and will not

c. Low water thermostat defective. c. Replace low water thermostat.

turn

off

when

water is added

to pan and no heat.

d. Buzzer cycles on

and off when pan is

dry.

d. Low water thermostat cycles off after

heater element cools down.

d. This is normal operation. Add water up to mark

in water pan.

a. Low water thermostat defective. a. Replace low water thermostat.

b. Buzzer defective. b. Replace buzzer.

c. Ballast resistor defective. c. Replace ballast resistor.

Buzzer does not

sound when water

pan is dry.

d. Water pan has just run dry. d. Normally water pan must be dry for 10-15

minutes before Buzzer will sound.

Power switch in ON

but:

a. Low water thermostat defective. a. Replace low water thermostat.

No thermostat

telite and no

heat.

PN 46

270

SH 2 OF 2

WIRING DIAGRAM FOR MDMW-1, 2&3LWC

120 VOLTS. SINGLE

PHASE WITH LOW

WATER SENSOR

BALLAST RESISTOR

WATTS VOLTS NOM. AMPS

900 120 7. 5

PLUS CONVENIENCE OUTLET

Wells Manufacturing Company

2 Erik Circle, P.O. Box 260

Verdi, NV 89439

(702)345-0444 May 08,1991

FAX: (702) 345-0569

SERVICE BULLETIN # 151-050891

TO: All Authorized Wells Service Centers

FROM: Allen K. Frandsen, National Service Manager

RE: Low water alarm and cut-off in Marinator Warmer.

Models covered by this bulletin: (MDMW) series McDonalds Marinators.

The Marinator Warmers manufactured for McDonalds has been upgraded to incorporate a low water

alarm and cut-off circuit. All current production units: MDMW-I, 2 and 3 now have "LWC" added to the

model identification plate.

This stands for "Low Water Cut-Off". Operation Is similar to the former models except that the unit will

shut down and sound a warning buzzer when the water has been allowed to run dry.

Attached is an addendum to the Service Manual covering the changes in the component parts, a wiring

diagram, a trouble shooting guide and a pictorial drawing.

A Retro-Fit Kit (PN:21505) is available (A copy of the instructions is attached) to modify Marinators in the field that

require the low water control circuit.

In order to successfully install the kit without difficulty, the water pan must not be warped, the thermostat

must be properly calibrated, inserts and lids must be in place. Failure to follow the instructions will result

in nuisance tripping of the alarm circuit.

AXF/dmd

Attachments: 46270 45932A

MANUFACTURERS OF QUALITY COMMERCIAL COOKING & WARMING EQUIPMENT

Wells Manufacturing MDMW-3/LWC User manual

Brand: Wells Manufacturing

Model: MDMW-3/LWC

Type: User manual

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Wells Manufacturing MDMW-3/LWC User manual

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