Maytag MAT12PDB, MAT12CSD, MAT12PSA, MAT12PDA, MAT12PDC User Manual

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Service

This manual is to be used by qualified appliance technicians only. Maytag does not assume any responsibility for property damage or personal injury for improper service procedures done by an unqualified person.

Commercial Top Load Washer

This Base Manual covers general information

Refer to individual Technical Sheet

for information on specific models

This manual includes, but is

not limited to the following:

MAT12PDA MAT12PDB MAT12PDC MAT12PDD MAT12PDS MAT12PRA MAT12PRB MAT12PRD MAT12PRS MAT12PSA MAT12PSB MAT12PSD MAT12CSA MAT12CSD MAT13MNA MAT13MND MAT13PNA MAT13PND

16022842

Revision 0

December 2003

Important Information

Important Notices for Servicers and Consumers

Maytag will not be responsible for personal injury or property damage from improper service procedures. Pride and workmanship go into every product to provide our customers with quality products. It is possible, however, that during its lifetime a product may require service. Products should be serviced only by a qualified service technician who is familiar with the safety procedures required in the repair and who is equipped with the proper tools, parts, testing instruments and the appropriate service information. IT IS THE TECHNICIANS RESPONSIBILITY TO REVIEW ALL

APPROPRIATE SERVICE INFORMATION BEFORE BEGINNING REPAIRS.

To avoid risk of severe personal injury or death, disconnect power before working/servicing on appliance to avoid electrical shock.

To locate an authorized servicer, please consult your telephone book or the distributor from whom you purchased this product. For further assistance:

Contact your local commercial product distributor or visit Web site www.maytagcommerciallaundry.com

Recognize Safety Symbols, Words, and Labels

DANGER

DANGER—Immediate hazards which WILL result in severe personal injury or death.

WARNING

WARNING—Hazards or unsafe practices which COULD result in severe personal injury or death.

WARNING

CAUTION

CAUTION—Hazards or unsafe practices which COULD result in minor personal injury, product or property

damage.

Table of Contents

Important Information .................................................... 2

Important Safety Information ......................................... 4

General Information

Model Identification .................................................... 7

Model Nomenclature .................................................. 7

How It Works ............................................................. 8

Tools For Servicing ................................................... 10

Troubleshooting Procedures

Mechanical Troubleshooting ..................................... 11

Drive Lug Adjustment .............................................12

Damper Pad Noise ................................................ 12

Pump Belt Adjustment...........................................12

Electrical Troubleshooting ........................................ 13

Component Testing ................................................ 14

Motor Testing .........................................................14

Disassembly Procedures ............................................. 16

Control Panel ............................................................16

MN (Manual) Timer ................................................... 16

CS (Coin Slide) Timer ...............................................16

Control Board (Microprocessor) ................................ 16

Touch Pad ................................................................ 17

Cycle Selector Switch .............................................. 17

Transformer .............................................................. 17

Motor Run Relay .......................................................17

Reversing Motor Relay .............................................. 18

Indicator Light ........................................................... 18

Lid Switch Assembly (Prior series 15) ...................... 18

Lid Switch Assembly (After series 15) ...................... 18

Unbalance Lever and Plunger Assembly ................... 19

Disassembly Procedures(continued) ...............................

Pressure Switch ....................................................... 19

Air Dome .................................................................. 19

Water Valve .............................................................. 20

Meter Case ...............................................................20

Coin Slide .................................................................20

Coin Drop Acceptor................................................... 20

Coin Sensor ..............................................................21

Service Door Switch ..................................................21

Coin Vault Switch ..................................................... 21

Lid ............................................................................ 21

Front Panel ...............................................................22

Top Cover .................................................................. 22

Tub Cover ................................................................. 22

Balance Ring ............................................................ 22

Agitator .....................................................................23

Access Plug ............................................................. 23

Inner Tub .................................................................. 23

Mounting Stem .........................................................24

Outer Tub ................................................................. 24

Tub Bearing .............................................................. 24

Transmission ............................................................ 25

Lip Seal .................................................................... 26

Damper Assembly .................................................... 27

Brake Package and Radial Bearing .......................... 27

Belts .........................................................................28

Drive Pulley and Rotor Bearing ................................. 28

Pump ........................................................................29

Drive Motor and Motor Base ..................................... 29

Important Safety Information

WARNING

To reduce the risk of fire, electric shock, serious injury or death to persons when using your washer, follow these basic precautions:

• Read all instructions before using the washer.

• Refer to the Grounding Instructions in the Installation Manual for the proper grounding of the washer.

• Do not wash articles that have been previously cleaned in, washed in, soaked in, or spotted with gasoline, dry-cleaning solvents, or other flammable or explosive substances as they give off vapors that could ignite or explode.

• Do not add gasoline, dry-cleaning solvents, or other flammable or explosive substances to the wash water. These substances give off vapors that could ignite or explode.

• Under certain conditions, hydrogen gas may be produced in a hot water system that has not been used for two weeks or more. Hydrogen gas is explosive. If the hot water system has not been used for such a period, before using a washing machine or combination washer-dryer, turn on all hot water faucets and let the water flow from each for several minutes. This will release any accumulated hydrogen gas. The gas is flammable, do not smoke or use an open flame during this time.

• Do not allow children to play on or in the washer. Close supervision of children is necessary when the washer is used near children. This is a safety rule for all appliances.

• Before the washer is removed from service or discarded, remove the lid to the washing compartment.

• Do not reach into the washer if the wash tub is moving.

• Do not install or store the washer where it will be exposed to water and/or weather.

• Do not tamper with the controls.

• Do not repair or replace any part of the washer, or attempt any servicing unless specifically recommended in the User-Maintenance instructions or in published user-repair instructions that you understand and have the skills to carry out.

• To reduce the risk of an electric shock or fire, do not use an extension cord or an adapter to connect the washer to the electrical power source.

• Use your washer only for its intended purpose, washing clothes.

• Always disconnect the washer from electrical supply before attempting any service. Disconnect the power cord by grasping the plug, not the cord.

• Install the washer according to the Installation Instructions. All connections for water, drain, electrical power and grounding must comply with

local codes and be made by licensed personnel when required. Do not do it yourself unless you know how!

• To reduce the risk of fire, clothes which have traces of any flammable substances such as vegetable oil, cooking oil, machine oil, flammable chemicals, thinner, etc. or anything containing wax or chemicals such as in mops and cleaning cloths, must not be put into the washer. These flammable substances may cause the fabric to catch on fire by itself.

• Do not use fabric softeners or products to eliminate static unless recommended by the manufacturer of the fabric softener or product.

• Keep your washer in good condition. Bumping or dropping the washer can damage safety features. If this occurs, have your washer checked by a qualified service person.

• Replace worn power cords and/or loose plugs.

• Be sure water connections have a shut-off valve and that fill hose connections are tight. Close the shut-off valves at the end of each wash day.

• Loading lid must be closed any time the washer is in operational fill, tumble, or spin. Do not attempt to bypass the loading lid switch by permitting the washer to operate with the loading lid open.

• Always read and follow manufacturer’s instructions on packages of laundry and cleaning aids. Heed all warnings or precautions. To reduce the risk of poisoning or chemical burns, keep them out of the reach of children at all times (preferably in a locked cabinet).

• Always follow the fabric care instructions supplied by the garment manufacturer.

• Never operate the washer with any guards and/or panels removed.

• Do not operate the washer with missing or broken parts.

• Do not bypass any safety devices.

• Failure to install, maintain, and/or operate this washer according to the manufacturer’s instructions may result in conditions which can produce bodily injury and/or property damage.

NOTE: The Warnings and Important Safety Instructions

appearing in this manual are not meant to cover all possible conditions and situations that may occur. Common sense, caution and care must be exercised when installing, maintaining, or operating the washer.

Always contact your dealer, distributor, service agent or the manufacturer about any problems or conditions you do not understand.

Important Safety Information

WARNING

To avoid personal injury or death from improper servicing, make sure you read and understand the descriptions and meaning of various safety symbols, words and labels used in this manual, before attempting any procedures described in the manual. Failure to understand and comply with safety information may result in severe personal injury or death.

General Information

This Service Manual describes the operation, disassembly, troubleshooting, and repair of Maytag washing machines. It is intended for use by authorized technicians who troubleshoot and repair these units.

NOTE: It is assumed that users of this manual are

familiar with the use of tools and equipment used to troubleshoot and repair electrical, and mechanical systems; and understand the terminology used to describe and discuss them.

About Ground Wires

In the event of an electrical short circuit, a ground wire reduces the risk of electric shock by providing an escape wire for the electric current. Standard accepted color coding for ground wires is green or green with a yellow stripe. Grounding wires and wires colored like grounding wires are NOT to be used as current carrying conductors.

WARNING

To reduce the risk of fire, electric shock, serious injury or death, all wiring and grounding must conform with the latest edition of the National Electric Code, ANSI/ NFPA 70, or the Canadian Electrical Code, CSA C22.1, and such local regulations as might apply. It is the customer’s responsibility to have the wiring and fuses checked by a qualified electrician to make sure your home has adequate electrical power to operate the washer.

WARNING

Related Publications

This is a base service manual, covering a range of similar models. It is intended to be used in conjunction with the Parts Manual and Technical Sheet covering the specific model being serviced.

Electrical Service Information

Proper Grounding and Polarization of 120 Volts Wall Outlets

For the safety of our customers and the Service Technician ALL appliances have a three–prong power cord and MUST be connected to a properly polarized AND grounded wall outlet. This information was written for those who do not understand grounding and polarization of a wall outlet. A 120 volt wall outlet must always be wired as shown below.

Ground

Neutral

V.A.C.

Neutral side

115±12

V.A.C.

To avoid risk of personal injury or death due to electrical shock:

• Observe all local codes and ordinances.

• Disconnect electrical power to unit before servicing.

• Ground appliance properly.

• Check with a qualified electrician if you are not sure this appliance is properly grounded.

• DO NOT ground to gas line.

• DO NOT ground to cold water pipe if pipe is interrupted by plastic, nonmetallic gaskets, or other insulating (nonconducting) materials.

• DO NOT modify plug on power cord. If plug does not fit electrical outlet, have proper outlet installed by qualified electrician.

• DO NOT have a fuse in the neutral or ground circuit. A fuse in the neutral or ground circuit could result in an electrical shock.

• DO NOT use an extension cord with this appliance.

• DO NOT use an adapter plug with this appliance.

• DO NOT pinch power cord.

Round grounding prong

115±12

V.A.C.

Important Safety Information

Explanation Polarization–This means that the larger slot must be

neutral and the small slot must be at line voltage. Mispolarized–The outlet is incorrectly wires so that the larger slot is at line voltage and the smaller slot is neutral. Grounded–This means the round hole connection is connected to earth ground through a connection to the main power panel. Ungrounded–The round hole connection is not complete to earth ground and/or the main power panel.

Grounding Instructions

WARNING

• To avoid the risk of electrical shock or death, do not alter the plug.

• Do not remove grounding prong when installing grounded appliance in a home that does not have three wire grounding receptacle. Under no condition is grounding prong to be cut off or removed. It is the personal responsibility of the consumer to contact a qualified electrician and have properly grounded three prong wall receptacle installed in accordance with appropriate electrical codes

• To avoid the risk of electrical shock or death, this equipment must be grounded.

This equipment MUST be grounded. In the event of an electrical short circuit, grounding reduces the risk of electric shock by providing an escape wire for the electric current. This unit is equipped with a cord having a grounding wire with a grounding plug. The plug must be plugged into an outlet that is properly installed and grounded. Consult a qualified electrician or technician if grounding instructions are not completely understood, or if doubt exists as to whether the equipment is properly grounded. Do not use an extension cord. If the product power cord is too short, have a qualified electrician install a three-slot receptacle. This unit should be plugged into a separate 60 hertz circuit with the electrical rating as shown in the appropriate drawing. Models operate with a supply voltage of 120 Volts.

General Information

Model Identification

Model and serial number is located on the back of the console and cabinet. It is important that you keep a record for future reference.

• For Maytag product call your distributor or visit the Web Site at www.maytagcommerciallaundry.com

When contacting provide product information located on rating plate. Record the following:

Model Number: ___________________

Serial or S/N Number: ___________________

Date of purchase: ___________________

Distributor name and address: ___________________

Commercial Washer Nomeclature

M AT WAAPD12

Service

Keep a copy of sales receipt for future reference or in case warranty service is required. To locate an authorized distributor:

• For Maytag product call your distributor or visit the Web Site at www.maytagcommerciallaundry.com.

Service should be performed by qualified service technicians. We also recommend contacting an authorized distributor, if service is required.

Parts and Accessories

Purchase replacement parts and accessories over the phone. To order accessories for your product call:

• or Maytag product call your distributor or visit the Web Site at www.maytagcommerciallaundry.com.

Only factory approved replacement parts should be used.

Brand

M - Commercial Maytag

Product Type

AT - Automatic Vertical

12 - Top Load Regular Tub 13 - Top Load Deep Tub

Model Number

This identifies which version of production the unit is

Control Type

CS - Mechanical coin slide ready MN - Mechanical non-coin PD - Microprocessor with coin drop PN - Microprocessor non-coin PR - Microprocessor debit reader ready PS - Microprocessor coin slide ready

Color Code

W - White Q - Bisque

Voltage Code

A - 120V 60Hz B - 120V 60Hz (Canada) G - 220 / 240V 50Hz (Generic Europe) E - 220 / 240 50Hz (U.K. Export)

Marketing Code

General Information

is important to understand that water pressure is the operation force in the water valve.

HOW IT WORKS

The cycles are made up of three basic operations Fill, agitate and drain/spin. These operations are sequenced by the controls (timer or microprocessor board) to provide a proper cleaning cycle for each of several different fabrics.

FILL

Pressurized hot and cold water supplies are required. The dynamic, or flow pressure should be between 30 lbs. per square inch and 80 lbs. per square inch (p.s.i.). Pressure below 20 lbs p.s.i. may cause water line hammering.

Hot water is describe to be 140° F and cold water temperature should be 75° F. A 50-50 mix of hot water and cold should result in warm temperature between 100° F and 105° F.

The components involved in a fill operation are the water valve assembly, the water level control and the timer or control board. The control board or timer along with the selector switch tell the valve whether to allow hot, cold or both (warm) into the washer. The water level control (a.k.a. pressure switch) controls the level of the water in the washer. It should be at the top row of holes (perforations) in the washer basket plus or minus 1/4 inch.

When the valve operating solenoid is energized, a magnetic field is produced that lifts the plunger away from the pressure release hole in the center of the diaphragm. The pressure in the guide tube area is released through the hole allowing the inlet pressure to lift the diaphragm off of the outlet seat. Water flows under the diaphragm and out through the valve outlet.

Because the bleed holes cannot allow water into the guide tube area as rapidly as it can escape out through the pressure release hole, the diaphragm will remain in the open position as long as the plunger is held away from the release hole.

When the plunger is released (solenoid coil de-energized), it again blocks the release hole allowing pressure entering though the bleed holes to again force the diaphragm back against the outlet seat, stopping the flow of water. A nozzle arrangement at the center of the diaphragm causes the valve closure to be gradual and smooth to reduce the chances of water hammer as the valve closes.

Water Level Control (Pressure Switch)

The water level switch is a single pole-double throw switch which is activated by air pressure increase against a sealed diaphragm. An air hose is connected to a spout at the bottom of the outer water container (outer tub) and to an inlet spout at the water level control body.

Water Valve (Non-Thermostatic)

The water valve used on the top load washers is designed to operate with in a pressure range of 30-120 p.s.i.. Flow pressure cannot fall below 20 p.s.i. or valves may fail to close when solenoids are de-energized.

Water from source enters valve at inlet and pushes up on diaphragm. The solenoid plunger and the plunger spring are not strong enough to hold the diaphragm in a closed position. The diaphragm lifted and some water will flow under the diaphragm and into the outlet.

Some water also flows through bleeder holes in the diaphragm and into the guide tube area behind the diaphragm. With the solenoid not energized, the plunger would block the pressure release hole allowing the guide tube to pressurize to source pressure. This causes the diaphragm to be pushed against the valve seat blocking the valve seat and closing the outlet.

While there is equal pressure (source pressure) on both sides of the diaphragm, the pressure in the guide tube area covers a greater surface area of the diaphragm. The center (outlet area) on the bottom side of the diaphragm is at atmospheric pressure so the valve remains closed. It

As water enters the tubs and the water level raises, air is trapped in the air dome at the bottom of the pressure switch hoses. As the water level increases, this air is pushed up the hose and against the diaphragm in the water level control body.

The control is designed to cause the contact points to switch when the water level in the wash basket (and the outer container) reach a particular level. At that point the fill circuits are disconnected and the motor circuit is energized. This corresponds to empty = fill and full = run.

Air leaks at the hose connections cannot be tolerated for proper operation of the water level control.

In timer models, a bypass circuit is provided by the timer and selector switch to continue power to the motor in spin operations. Without the bypass, the drive motor would stop when sufficient water had been pumped out of the washbasket to cause the pressure switch to reset to the ”empty” position. Microprocessor models do not need the bypass circuit.

General Information

DRIVE MOTOR

When the water level/pressure switch is satisfied circuits are completed to the main drive motor. The drive motor is a special high torque split-phase, four pole motor. Two windings are used. The run winding is designed for full time use in wash and spin. A second winding, called the auxiliary or “start” winding is used to provide starting torque and determine direction of rotation. A centrifugal switch is mounted to the upper end bell of the motor and serves to disconnect the start winding as the motor reaches running speed.

Contact sets in a timer or in a motor reversing relay provide proper connection to the motor to cause it to run clockwise in agitate and counterclockwise in spin (viewed from the top).

The motor drives the power unit by means of a special design “V” belt. The belt has a “slip factor” designed to act as a slip clutch.

rotates down the shaft, a lug on the pulley comes against a drive lug which is splined to the helical drive shaft. At this point the drive shaft turns with the pulley. The pulley bearing which merely resting on top of the pulley also rotates with the pulley, drive lug and helical drive shaft.

At the top of the drive shaft is a spined gear. As it rotates it drives a series of gears causing the agitator to move back and forth in an arc creating the water action for the wash.

The tub and transmission are locked in place and cannot turn because the brake rotor and brake shoe (which is splined to the transmission ) is being held down against the brake drum by the brake spring.

SPIN

When the motor reverses, the pulley will turn in a clockwise (viewed from the bottom). This causes the pulley and bearing to turn. The pulley climbs the threads on the helical drive shaft overcoming the force of the brake spring to lift the brake rotor and brake shoe off the brake drum.

TRANSMISSION

The helical drive shaft drives a pinion gear (which is splined to the top of the drive shaft) at approximately 618 r.p.m. This drives the bevel gear at approximately 150 r.p.m.

The pivot pin of the yoke portion of the torque block and yoke assembly is driven in a circular motion (orbit) around an imaginary center point of the bevel gear center axis. The yoke drives the torque block back and forth through an arc of approximately 97 degrees at the rate of about 150 times per minute. Because this is a continuous motion, the drive provides very smooth operation. The low number of parts results in improved dependability. This gear case can be serviced without removing it from the washer.

HELICAL DRIVE

The helical drive mechanism used in the washer is simple

- not requiring a special device or linkage to shift the washer from agitation to spin.

The drive mechanism utilizes a reversible motor and helical (threaded) drive shaft. A pulley which is threaded to the helical drive shaft moves either up or down the shaft dependent upon the direction it is turned by the drive motor by means of a drive belt.

As the pulley climbs the shaft and overcomes the force of the brake spring, there is a downward pull on the shaft.

Within the transmission there are two washers which act as a spin clutch. This is a friction clutch consisting of a bronze washer which is splined to and turns the drive shaft. Between this washer and the pinion gear is a steel washer which is locked to the transmission case.

As the helical shaft is pulled downward, the two clutch washers under the pinion are forced together. This is done rapidly and slippage occurs only during the first two or three revolutions, until the film of oil between the two clutch washers is forced out.

The drive occurs when the washers are forced together and the pulley has climbed the shaft as far as it can. The driving force has locked the pulley, brake rotor, drive tube and gear case together and all will turn as a unit in the same direction as the pulley is turning, causing the tube to spin is a counterclockwise direction (as viewed from the top).

Spin cycle completed:

When the washer reaches the end of the spin cycle, the drive force is removed. Thus, there is no force supplied to lock the components together or to compress the brake spring. Therefore, the downward force of the brake spring and the momentum of the spinning washbasket effectively reverse all the actions outlined above.

AGITATION

When the pulley is turning counterclockwise (viewed from the bottom) it moves down the helical drive shaft. As it

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