Maytag Mfs25pn User manual

Maytag

Commercial

MFS25PN

MFS35PN

MFS50PN

MFS75/80PN

MFS90/1

OOPN

MFS125P

MA

Front

Load

Washers

Service

Manual

16009607

Issued

7/99

GENERAL SAFETY PRECAUTIONS

Information

contained in this manual is

intended

for

use

by

a qualified service technician

familiar

with

proper

and safe

procedures

to

be

followed

when

repairing an electrical ap-

pliance. Alf tests and repairs

should

be

performed

by

qualified service technicians

equipped

with

proper

tools

and measuring devices. Alf

component

replacements

should

be

made

by

a

qualified service technician using

only

factory

approved

replacement

parts.

Improper

assembly

or

adjustment

may

occur

if

service

or

repair is

attempted

by

persons

other

than qualified service technicians

or

if

parts

other

than

approved

replacement

parts are used.

Improper

assembly

or

adjustment

can create hazardous conditions.

There can be risk

of

injury

or

electrical shock

while

performing

services

or

repairs.

Injury

or

electrical shock can be serious

or

even fatal. Consequently,

extreme

caution

should

be

taken

when

performing

voltage

checks on individual

components

of

a

product.

PLEASE

NOTE:

Except as necessary

to

perform

a particular step in servicing a

product,

the electrical

power

supply

should

ALWAYS be disconnected

when

servicing a product.

Further, this appliance

MUST

be

properly

grounded.

Never plug in

or

direct

wire

an appliance

unless it is

properly

grounded

and in accordance

with

all local and national codes. See

installation

instructions

that

accompany

the

product

for

grounding.

16009607

Safety Precautions

INTRODUCTION

The

information

contained

in

this

manual

pertains

to

the service

procedures

involved

in

main-

taining

and/or

servicing

the

Maytag

"MFS25-125" (soft

mount)

models.

These

models

are

front

load

washers

intended

for

use in

commercial

installations.

Specifications

are

included

in

this

manual as a

guide

to

assist in

performance,

installation, and

servicing

of

the

product.

As

on

other

front

washer

models,

the

importance

of

proper

installa-

tion

cannot

be

over

emphasized. For additional

information,

refer

to

the

installation instruc-

tions

that

accompanies

each

front

load washer.

This

manual

is

divided

into

five

sections

covering

the

front

load washer. Refer

to

those

sec-

tions

for

general

information.

If additional

information

is required,

contact

your

commercial

distributor.

Section

1 - Covers general

information

on

ordering

parts,

how

to

operate the washer, electrical

test

equipment,

safety rules and maintenance.

Section

2 - Provides

information

on the location

of

components

and service

procedures.

Section

3 - Provides

information

on

programming

and set-up procedures.

Section

4 - Covers general

troubleshooting.

Section

5 - Provides specifications, and

wiring

diagram

information.

16009607

MODELS COVERED IN THIS

MANUAL

MFS25PN

MFS50PN

MFS75/80PN

MFS90/100PN

MFS125P

NOTES

16009021

Introduction

ii

CONTENTS

GENERAL SAFETY PRECAUTIONS ...................................................................................................i

INTRODUCTION .................................................................................................................................ii

CONTENTS

........................................................................................................................................iii

SECTION 1. GENERAL

INFORMATION

.........................................................................................1-1

HOW

TO ORDER PARTS ..............................................................................................................

1-1

MEANING

OF THE SYMBOLS ON THE LABELS .........................................................................1-2

SAFETY RULES .............................................................................................................................1-3

SAFETY RULES CHECK LIST .......................................................................................................1-3

MAINTENANCE .............................................................................................................................1-4

LUBRICATION ................................................................................................................................1-4

ELECTRICAL TEST EQUIPMENT..................................................................................................1-6

HOW

IT

WORKS

...........................................................................................................................1-7

SECTION 2. SERVICE PROCEDURES ...........................................................................................2-1

CABINET PANELS .........................................................................................................................

2-1

TOUCHPAD ....................................................................................................................................

2-1

CONTROL BOARD ........................................................................................................................2-2

MICROPROCESSOR CHIP ............................................................................................................2-3

SWITCH SETTING (MKllA-20) ......................................................................................................2-4

EMERGENCYSTOP.......................................................................................................................2-4

SERVICE DISCONNECT SWITCH .................................................................................................2-4

CONTACTORS ...............................................................................................................................2-4

CURRENT OVERLOAD PROTECTORS .........................................................................................2-5

FUSES ............................................................................................................................................2-5

CONTROLTRANSFORMER ..........................................................................................................2-5

OUT-OF-BALANCE SWITCH .........................................................................................................2-6

OVERFLOW ...................................................................................................................................2-6

VENTS ...........................................................................................................................................2-6

WATER LEVEL CONTROL.............................................................................................................2-7

INLET VALVES ...............................................................................................................................2-7

Valve Repair .............................................................................................................................2-8

Water

Distribution

...................................................................................................................2-8

Water

Filters.............................................................................................................................2-9

Liquid

Chemical

Supply

Injection

Provision .........................................................................2-9

DOOR ASSEMBLY ........................................................................................................................2-9

DOOR LOCK OPERATION ...........................................................................................................2-11

WASH

BASKET ...........................................................................................................................2-12

BEARINGS

AND

SEALS..............................................................................................................2-13

MOTORS ......................................................................................................................................2-16

CLUTCH ......................................................................................

'.

................................................2-17

V-BELTS .......................................................................................................................................2-17

SUSPENSION ASSEMBLY..........................................................................................................2-18

Shock

Absorbers

...................................................................................................................2-18

Springs

...................................................................................................................................2-18

DRAIN VALVE ..............................................................................................................................2-19

16009607 Contents

iii

SECTION 3.

PROGRAMMING

AND

SET-UP PROCEDURES ......................................................

3-1

TOUCHPAD FUNCTIONS .............................................................................................................

3-1

ENTERING THE TYPE OF MACHINES......................................................................................... 3-2

CODE OVERVIEW ........................................................................................................................ 3-2

SECTION 4.

TROUBLESHOOTING

............................................................................................... 4-1

GENERAL INFORMATION ............................................................................................................

4-1

COMPONENTS .............................................................................................................................

4-1

MECHANICAL

TROUBLESHOOTING ..........................................................................................

4-1

DISPLAY MESSAGES .................................................................................................................. 4-3

SECTION 5. SPECIFICATIONS &

WIRING

SCHEMATICS...........................................................

5-1

FUSE CHART................................................................................................................................

5-1

CURRENT OVERLOAD PROTECTOR SETTINGS ........................................................................

5-1

ELECTRICAL REQUIREMENTS .................................................................................................... 5-2

MOTOR HORSEPOWER (KW) ..................................................................................................... 5-2

BASKET SPEED ........................................................................................................................... 5-3

RESISTANCE CHART................................................................................................................... 5-3

DRAIN CONNECTIONS ................................................................................................................ 5-3

WATER CONNECTIONS ............................................................................................................... 5-4

BOLT

AND

NUT

TORQUE (MFS50) ............................................................................................. 5-5

BOLT

AND

NUTTOROUE

(MFS75-125) ...................................................................................... 5-6

WIRING SCHEMATICS ................................................................................................................. 5-7

MICROPROCESSOR VERSION - 2 MOTORS (MFS75PN &MFS80PN) Legend ........................ 5-8

MICROPROCESSOR VERSION - 2 MOTORS (MFS95 & MFS100) Legend ............................... 5-9

MICROPROCESSOR VERSION - 2 MOTORS (MFS125PN) Legend ........................................ 5-10

CONTROL CIRCUITS (MFS25 &MFS35) ................................................................................... 5-11

POWER CIRCUITS (MFS25 &MFS35) ....................................................................................... 5-12

CONTROL CIRCUITS (MFS550)................................................................................................. 5-13

POWER CIRCUITS (MFS50) ....................................................................................................... 5-14

CONTROL CIRCUITS (MFS75 &MFS80) ................................................................................... 5-15

POWER CIRCUITS (MFS75 & MFS80) ....................................................................................... 5-16

CONTROL CIRCUITS (MFS95 & MFS100) ................................................................................. 5-17

POWER CIRCUITS (MFS95 & MFS100) ..................................................................................... 5-18

CONTROL CIRCUITS (MFS125) ................................................................................................. 5-19

POWER CIRCUITS (MFS125) ..................................................................................................... 5-20

16009607 CONTENTS

iv

SECTION

1.

GENERAL INFORMATION

HOW

TO ORDER PARTS

Spare parts can be ordered

from

the authorized Maytag commercial

distributor

who

sold the

machine

or

from

a commercial distributor designated service firm.

IT

IS

RECOMMENDED THAT GENUINE

FACTORY

REPAIR

PARTS

BE

USED.

USE

OF

OTHER

PARTS

MAY HARM UNIT

OR

CAUSE OPERATIONAL PROBLEMS.

When contacting

or

ordering parts

from

your

distributor regarding the machine

or

service,

always have the

following

information ready:

Insert

Your

Information

Below:

Machine Model Number:

Machine Serial Number:

Installation Date:

:;

Distributor's Name:

Address:

City, State, Zip Code:

Person

To

Contact &

Telephone Number:

Note:

It

is

helpful

to

maintain

service

records

associated

with

each

product.

16009607 Section

1.

General

Information

1-1

MEANING

OF

THE SYMBOLS ON THE LABELS

WARNINGS:

& Caution -

Dangerous

voltage,

electricity

.6.

Caution -

Other

hazard

& Caution -Increased

temperature

>

'•A

Caution -Device sensitive

to

electrostatic, discharge

memory

corruption

hazard

INFORMATION:

Wash

detergent

hopper

Liquid

supply

pumps

STOP -

The

machine

emergency

stop

(control circuits are

switched

off)

If

1+1111

,_-,

L....J L....J

"'

..

Direction

of

the

drum

rotation

during

prewash

+

wash

Direction

of

the

drum

rotation

during

spin

Do

not

touch

marked

area

Steam

~Outlet

of

hot

air

from

the

machine

16009607

Transfer

of

heat in general

Do

not

close,

do

not

cover

Section

1.

General

Information

1-2

SAFETY RULES

This

is

the

most

important

section

in

the

manual. It describes

the

safety and mainte-

nance rules applicable

to

anyone

servicing

or

operating

the

machine,

including

the

owner

of

the

machine.

Please read

this

information

and

retain

for

reference.

Warning:

This

machine

is

equipped

with

devices

and

features relating

to

its safe

operation.

To

avoid

injury

or

electrical shock,

DO

NOT

perform

any

service unless qualified

to

do

so.

Information

to

owners,

operators

and

dealers:

Warning:

Improper

and inadequate

mainte-

nance,

poor

machinery

housekeeping and

neglect

or

bypassing

of

safety devises

may

result in

accidents

involving

personal

injury

and/or

property

damage.

To ensure

the

safety

of

operators

of

your

machine,

the

following

maintenance

checks

MUST

be

performed

on aDAILY

BASIS.

1.

Prior

to

operating

the

machine, check

to

make

certain

that

all

warning

signs

are

present

and legible.

Missing

or

illegible

ones

must

be replaced

immedi-

ately.

Be

sure

you

have spares available

at

all

times.

2. Check

the

door

safety

interlock

as

follows:

•

Open

the

door

of

the

machine

and

attempt

to

start in

the

normal

manner.

• Close

the

door

to

start

machine

opera-

tion

and

while

it

is

operating

attempt

to

open

the

door.

The

door

must

re-

main

locked.

•

Upon

completion

of

the

cycle,

imme-

diately

check

that

the

cylinder

has

stopped

and

cycle

indicator

is off.

Warning:

DO NOT,

under

any

circum-

stances,

attempt

to

bypass

any

of

the

machine

safety

devices

as

this

can

result

in accidents

involving

personal

injury

and/or

property

damage.

3.

Be

sure

to

keep

the

machine(s) in

proper

working

order

and

follow

all

maintenance

and safety

procedures.

Use

only

genuine

factory

repair parts.

ASSISTANCE:

All

requests

for

assistance

must

include

the

model,

serial

number

and

the

electrical characteristics as

they

appear

on

the

machine

identification

plate.

Warning:

DO

NOT

OPERATEMACHINE(S)

WITH

SAFETY

DEVICES

BYPASSED

OR

INOPERATIVE.

DO

NOT

ATTEMPT

TO

OPEN

MACHINE

DOORUNTIL CYLINDER

HAS

STOPPED

ROTATING.

SAFETY RULES CHECK LIST

•

Thoroughly

review

the

appropriate

section

of

the

service

manual

before

attempting

any

repair

or

maintenance

of

the

machine.

Always

shut

off

power

and

water

supply

before

maintenance

or

servicing.

• Do

not

overload

the

machine.

• Do

not

attempt

to

open

the

door

when

the

cylinder

is in

motion

or

if it

contains

water.

• Do

not

bypass

the

safety

devices

in

this

machine. ·

•

Immediately

repair

any

seepage in

the

system

due

to

faulty

gaskets, etc.

• Do

not

spray

the

machine

with

water;

it

may

cause

short

circuit

and

serious

damage.

16009607 Section

1.

General

Information

• Do

not

use

volatile

or

flammable

sub-

stances in

or

near

this

machine.

• Keep all panels in place.

They

protect

against

shock

and

injury

and add

rigidity

to

the

machine.

• Make sure all

warning

signs

are

present

and

legible. Replace

immediately

if

lost

or

damaged.

• Do

not

replace

control

fuse

with

one

of

greater

value

or

amperage.

Do

not

attempt

to

operate

a

machine

if

any

of

the

following

occurs:

• Excessively

high

water

level.

•

Machine

is

not

connected

to

a

properly

grounded

circuit.

•

Door

does

not

remain

securely

locked

during

the

entire cycle.

MAINTENANCE

General

Even

though

preventative

maintenance

has

been

reduced

to

a

minimum

by

the

careful

design

of

this

machine

and

the

choice

of

components,

it

is necessary

to

maintain and

keep

the

machine

clean. This

will

prolong

the

life

of

the

machine

and

avoid

hours

of

service

to

the

machine.

Warning:

BEFOREPERFORMING

ANY

SER-

VICE

MAINTENANCE,

MAKE

SURE

THAT

MAIN

POWER

TO THE

MACHINE

IS

SWITCHED

OFF.

Daily:

• Check

door

lock

and

interlock

before

start-

ing

operation.

• Clean

soap

dispenser

area.

• Clean

the

cabinet.

• Check drain

for

leaking and

proper

opening.

• Check

the

loading

door

for

leaks. Clean

the

door

seal

of

all

foreign

matter.

• Leave

loading

door

open

to

air

out

the

entire

washer

at

the

end

of

the

cycle and

at

the

end

of

the

day.

Quarterly:

• Check V-belts

for

wear

and

proper

tension.

• Check

motor

hinge

system

and

clean

lint

from

motor.

• Check all

water

connections

and

hose

connections

for

leaks.

Tighten

or

replace

as needed.

• Check

mounting

bolts. Retighten

if

neces-

sary. (If equipped).

• Remove and clean

water

inlet

valve and

hose filters. Replace

if

necessary.

•

Wipe

and clean the inside

of

the

washer

and check

that

all electrical

components

are

free

of

moisture

and dust.

• Check/tighten

contactor

terminal

screws

and

inspect

connections

in

control

panel

area.

IMPORTANT

Replace

any

and

all

panels

that

were

removed

to

perform

daily

and/or

quar-

terly

maintenance.

Semi-annual:

•Clean

water

inlet filter

LUBRICATION

Main

Bearing

and

Seals:

Whenever

applying

grease

to

the

grease

fittings

located

on

the

machine,

let

the

drum

rotate

during

the

low

speed

of

the

wash

cycle.

The

grease

should

be

applied

at

a rate

of

five strokes

per

minute.

Amount

of

grease

to

be

applied

is 2

lever

strokes

after

the

first

200

hundred

hours

and

thereafter

once

every

16009607 Section

1.

General Information

1000

hours

of

operation

of

the

machine. See

Figure

1-1 & 1-2.

NOTE:

Bearing

and

sealsare

permanently

lubricated

on

the

MFS25-35-50

model

ma-

chines.

Other

Components:

Every

six

months

or

as needed grease

the

suspension

spring

eyes & rods,

door

handle

&

hinge

sleeves.

Recommended

Grease:

Multi-purpose

lithium

grease rated at least

the

equivalent

of

one

of

the

following:

1)

NLGl2

2)

SKF-LGEP2

3)

ESSO -Beacon

EP2

3

1.

Rubber

seal

2.

Front

bearing

3.

Rear bearing

Figure 1-1

16009607

1S

SEAL

BEARINGS

FRONT

BACK

LUBRICATION • SEE MANUAL

Figure 1-2

Section

1.

General Information

ELECTRICAL TEST EQUIPMENT

The

equipment

required

to

service

Maytag

products

depends

largely

upon

the

conditions

you

encounter. Locating a

malfunction

will

often require

the

use

of

electrical

testing

equipment

such as:

Digital

Test

Meter

can be used

to

check

for

open

or

closed

circuits,

measure

resistance,

AC and

DC

volts,

and

temperature.

16009607

Description

Analog

Test

Meter

Digital Test

Meter

Clamp-On

Ammeter

AC Voltage

Sensor

Part

Number

20000005

20001001

20000002

20000081

Clamp-On

Ammeter

can be used

to

detect

shorts. Over-

loads on

the

circuit

breaker

or

fuse can

be traced

to

either the

washer

or

circuit

breaker

by

checking the

washer

current

draw.

AC

Voltage

Sensor

can be used

to

alert

you

if

AC

voltage

is

present

so

proper

safety

precautions

can be

observed.

The

tip

of

the sensor

will

glow

bright

red,

if

voltage

is

between

110-600

volts

AC.

Section

1.

General Information

HOW IT WORKS

The

Maytag

MFS {Maytag Front-Load Soft-

Mount)

models

are

"suspension

type"

wash-

ers

in

which

the

operating

mechanisms

are

spring

and

shock

absorber

suspended

from

a

heavy

support

frame

within

the

exterior

cabinet.

This

"floating"

suspension

allows

out-of-balance

energy

to

be dissipated

through

acceptable restricted

movement

within

the

suspension

system

without

the

need

to

secure

the

machine

to

a large

floor

mass. These

systems

allow

higher

extract

speeds

to

remove

more

water

from

the

wash

loads

for

faster

drying.

Multiple

drive

motors

and

in

some

cases

electro-mechanical

clutches are used

to

drive

the

washbaskets

in wash,

distribution,

low

speed

extract

and

high

speed extract. For

example

the

wash

motor

may

have

windings

for

wash

speed

and

distribution

speed. The

spin

or

extract

motor

will

have

windings

for

low

speed spin

and

for

high

speed spin.

Multiple

belts are used

to

transfer

power

eventually

to

the

basket

drive

pulley. In

some

models

a clutch is used

to

disengage

the

wash

motor

at

spin speeds

to

prevent

exces-

sive RPM

of

the

wash

motor

bearings.

Washer

"cycles"

are

controlled

by

a

twenty

program

microprocessor

control

board

that

allows

modifications

to

be

made

to

water

temperature,

water

level, cycle steps, cycle

times

and chemical

injection

signal

outputs.

An

alpha-numeric

"liquid-crystal"

display

screen displays cycle

progress

and

program

information

to

the

operator.

Audible

signals

can be set along

with

pause

of

cycle

to

allow

use

of

manually

added

laundry

chemicals.

Service

due

reminders

may

also be set in

the

program.

An

emergency

push-to-stop

button

is located

on

the

operating

panel in case

there

is a need

for

a

quick

shut

down.

In

addition

a

rotary

main

power

switch

is located

on

the

washer

rear panel and a three pole

manual

circuit

breaker is located in

the

controls

tray

near

the

motor

contactors.

The

rotary

switch

is

useful as a service disconnect.

Normal

operation

may

also be

terminated

by

press-

ing

the

"Stop"

pad

of

the

cycle

selector

keypad.

16009607 Section

1.

General

Information

1-7

NOTES

16009607 Section

1.

General Information

SECTION

2.

SERVICE PROCEDURES

IMPORTANT

~~~~~~~~-,

•

Extreme

caution

should

be

taken

when

performing

voltage

checks

due

to

danger

of

possible

electrical

shock.

•

Except

as necessary

to

perform

a

paticular

step

in

servicing

a

product,

the

electrical

power

supply

should

ALWAYS

be

disconnected

when

servicing

a

product.

CABINET PANELS

Back:

The back panel

assembly

can be one

or

two

pieces

{depending

on model). Panels are

attached

with

either

Phillips head screws

or

10

mm

hex

head screws.

Side:

The side panels can

either

be

one

or

two

pieces

(depending

on model).

They

are

attached

with

either

Phillips head screws

or

10

mm

hex

head screws. In

some

cases the

side panels are secured in place

by

a

combi-

nation

of

both

types

of

screws.

Top:

The

top

panel is

hinged

and

secured

by

locks

on

MFS25-50. On MFS75-125

the

panel is

secured

to

the

cabinet

with

screws. On

the

larger

models

the

top

panel is

not

hinged

and

may

be

one

or

two

panels.

Lower

Front:

The

lower

front

panel is secured

by

screws.

The

number

of

screws

can

vary

depending

on

model.

This

panel is

removed

by

remov-

ing

the

screws

and lifting

upward

on

the

panel.

TOUCHPAD

The

touchpad

is a one piece

membrane

switch

that

is secured in place

with

an adhe-

sive backing. The

touch

pad has 20 keypads

and is used

to

select

washing

programs

and/

or

to

program

cycles. See

Figure

2-1.

Cleaning:

Remove

dirt

from

the

touch

pad

with

a

slighlty

damp

cloth after having

turned

off

power

to

the washer. DO

NOT

use abrasive

houshold

soap,

corrosive

chemicals, gasoline

Figure2-1

16009607 Section

2.

Service Procedures

Company

2-1

or

other

petrochemical

agents

which

may

damage

the

touchpad.

Removal:

1.

Disconnect

Power

to

the

machine.

2.

Unplug

touch

pad

connector

from

the

control

board.

3.

Remove

the

front

facia.

Some

models

may

require

the

removal

of

the

soap

box

covers

first.

4. Pull

the

old

touchpad

off

of

the

stainless

steel plate, clean

the

panel surface

throughly

before

reinstalling

the

new

touchpad.

5.

Connect

the

new

touchpad

connector

to

the

control

board.

6.

Reinstall

the

front

facia.

7.

Reconnect

the

power

supply.

CHECKING TOUCH PAD:

The

touch

pad

may

be checked

with

an

ohmmeter

according

to

the

folowing

chart.

Keypad

Position

Ribbon

Connection

1 1

to

8

2 2

to

8

3 3

to

8

4 1 to 7

5 2

to

7

6 3 to 7

7 1

to

6

8 2 to 6

9 3

to

6

0 2

to

5

STOP

1

to

5

START

3

to

5

ADV

4

to

5

PROG

9

to

5

TIME

4

to

6

NO

4

to

7

YES

4

to

8

16009607

CONTROL BOARD

The

control

board

provides

signals

to

a

number

of

components.

It also senses

input

information

from

a

variety

of

components

(i.e.

water

level, safety

switches,

temperature

sensor, etc). In general

the

control

board

is

divided

into

a series

of

inputs,

outputs.

Viewing

Angle:

The

viewing

angle

of

the

display

(see

figure

2-2.) can be adjusted

by

turning

the

potenti-

ometer

R7

with

a small screwdriver.

0

display

~

P--

Contrast

~

/

viewing

angle

Figure2-2

Removal:

1.

Disconnect

power

to

the

machine.

2.

Remove all

connectors

from

the

control

board.

3.

Remove

the

nuts securing

the

control

board

to

the panel.

4.

Remove

the

control

board.

5.

Make sure

the

SW1

switch

of

the

new

control

board

is in

the

same

position

as

on the

old

control

board. See

Figure

2-3.

for

position

of

SW1 (machine

type

selec-

tion).

6.

Install

microprocessor

chip(memory

chip)

from

the

old

control

board

or

with

the

same software. See

Microprocessor

Chip

Replacement

Section

(make sure all

pins

are

in

socket}.

Section

2.

Service Procedures

2-2

1 2

5 6

1.

Control

Board

2.

Microprocessor

(microporcessor

soft-

ware

version

and date identification

e.g. APL

V1

.02

3.

Machine

type

switch

3

4.

Board serial

number

(e.g. SERIAL

00015)

5.

Touchpad

connector

6.

Potentiometer

R7

7.

MPN (code

number)

Figure2-3

7.

Mount

the

new

control

board

in place and

secure

with

nuts. Make sure

that

the

display

does

not

touch

the

front

stainless

steel plate (keep at least .08 inches (2mm)

away

from

plate).

8.

Reconnect all

connectors

before

restoring

power

to

the

washer.

MICROPROCESSOR CHIP

The

microprocessor

chip

is sensitive

to

electrostatic

charges. Careless

manipulation

or

strong

electrostatic

fields

can

damage

the

software.

Removal:

1.

Disconnect

power

to

the

machine.

2.

Remove

the

microprocessor

chip

from

its

mounting

base.

3.

Place

the

new

microprocessor

chip

cor-

rectly

into

the

mounting

base

making

sure

the

pins are

not

bent

(align

positioning

mark). Generally the

alignment

notch

is

on the

top

side.

4.

Restore

power

to

washer.

5.

Complete

initialization

procedures

are

covered

in the

Programming

and

Opera-

tion

Manual.

6.

After

you

have

completed

the

initializa-

tion, be sure the

programming

switch

is

operating

in

the

mode

"RUN"

position

(if

the

machine

is

equipped

with

a switch).

16009607 Section

2.

Service Procedures

SWITCH SETTING (MKllA-20}

The

machine

type

(SW1)

switch

(see Figure 2-3)

on

the

MKllA-20

can be used

to

configure

the

software

for

different

types

of

machines.

Soft-Mount

(MFS) Type

Machines

25-351b (10-16 KG)

7

for

machines

with

3

inlet

fill lines

4

for

other

machines

Soft-Mount

(MFS) Type

Machines

50-1251b (22-55 KG)

3

for

machines

with

two

door

coils, 3

inlet

fill lines

4

for

machines

with

two

door

coils, 3

inlet

fill lines, 2 drain fill lines

7

for

machines

with

two

door

coils, 2

inlet

fill lines

9

for

machines

with

two

door

coils, 2 inlet, 2 drain fill lines

EMERGENCY STOP

The

emergency

switch

is a

double

pole,

double

throw

switch

that

is in series

with

both

sides

of

the

line voltage.

When

the

switch

is

pushed

in,

both

sides

of

line

voltage

is

disconnected

and

illuminates

a

light

indi-

cating

that

the

emergency

switch

has been

tripped.

NOTE:

DO

NOT

use

this

switch

and

assume

allline voltage

is

eliminated

to

the

machine,

when

servicing

the

product.

Power

is

still

on

at

the

motor

contactor

and

other

controls tray points.

SERVICE DISCONNECT SWITCH

A service

disconnect

switch

is located

at

the

rear

of

the

machine.

The

switch

is a

two-

position,

rotary

switch

and is red in color.

The

service

disconnect

switch

serves as

the

connection

point

for

the

3 phase

power

to

the

machine

and

is

marked

OM.

As

connected

in

the

factory, in

the

"Off"

position

(0)

all

power

is

removed

from

the

machine.

The

"On"

position

(I)

switches

three

phase

power

to

the

circuit

breaker and

control

transformer

of

the

machine.

CONTACTORS

Electrical

current

is

supplied

to

the

motors

via contactors. A

contactor

is a

type

of

high

current

relay

with

a

movable

core, a sole-

noid, and a

multiple

contact

assembly. The

contactors

are

designed

to

handle

the

motor

loads and

current

inrush

at start

for

all

model

machines.

MFS

models

use

motors

with

two

separate

windings

per

motor,

allowing

the

basket

to

turn

at

4

different

speeds:

wash

speed,

distribution

speed,

low

speed spin,

and

high

speed spin. Each speed is

supplied

current

by

a separate contactor.

The

contactors

are

marked

as

follows:

KMP

KML

KM1

KM2

KM3

KM4

Wash -

right

rotation

Wash -

left

rotation

Distribution

Low

Spin

Shorting

High

Spin

The

solenoids

of

KM3

and

KM4

are con-

nected

in

parallel

and

should

always

be

engaged

together

when

the

machine

is in

high

speed spin. The

purpose

of

the

shorting

contactor

is

to

convert

the

motor

from

a delta

connection

to

a

double

wye

connection,

16009607 Section

2.

Service Procedures

allowing

more

starting

torque

with

less

amperage

while

the

machine

is accelerating

to

full

high

spin speed.

The

wash

contactors

(KMP and KML) are

mechanically

interlocked

together

to

prevent

them

from

ever

engaging

simultaneously.

Low

Spin

and

Shorting

(KM2 and KM3) are

also

mechanically

interlocked.

Installed across contacts

of

the

wash

contactors

(KMP

and

KML) are

RC

(resistor-

capacitor)

networks

identified

as

Z1

and Z2.

These

function

as EMI filters and reduce

arcing

of

the

contacts

when

the contactors

are

engaged

and

disengaged. If EMI interfer-

ence-related

control

board

problems

are

encountered,

the

RC

networks

should

be

checked.

CURRENT OVERLOAD PROTECTORS

On

many

MFS

models,

current

overload

protectors

are installed

piggybacked

to

the

input

side

of

the

contactors. One

current

overload

protector

will

be installed on

the

input

of

the

contactors

that

supply

current

to

the

wash

motor

(KMP,

KML, and KM1) and is

identified

as

FA

1.

A second

current

overload

protector

is installed on

the

inputs

of

the

contactors

that

supply

current

to

the

spin

motor

(KM2, KM3, and KM4) and is identified

as FA2.

Consult

the

wiring

diagram

that

comes

with

the

machine

for

proper

setting

of

the

current

overload

protector.

The

current

overload

protector

is connected

as a

normally

closed switch in series

with

power

to

the solenoids

of

the contactors in

which

it

is connected. If

an

overcurrent

is

detected, the switch

will

open

removing

power

from

the

contactor

solenoids, prevent-

ing

them

from

engaging until the current

overload

resets. If a

current

overload protec-

tor

opens

during

a cycle, the "Overload Fault"

code

will

appear on the

control

board display.

If a

current

overload

protector

is open at

the

start

of

a cycle, the "Close

Door

Press Start"

code

will

appear

on

the

control

board display.

CIRCUIT BREAKER

The

entire

contactor

set is

protected

by

a

separate

circuit

breaker

and

is

identified

as

FA. This

circuit

breaker is installed in

the

3

phase line

that

feeds all

the

inputs

of

the

contactors and is located in

the

same

area as

the

contactors. If

the

circuit

breaker is

open

(off}, there

will

be

no

motor

function,

regard-

less

of

whether

the

computer

display

indi-

cates a cycle is in progress,

or

if

the

contactors engage and

disengage

in a nor-

mal manner.

FUSES

Each

machine

is

protected

by

fuses installed

in the lines

that

feed the

controls

of

the

machine. The

input

(primary)

of

the

control

transformer

is fused on

both

the

Line 1 and

Line 2 sides,

as

well

as fused

with

one

fuse

on

the

output

(secondary) side

of

the

control

transformer.

On

most

machines,

provision

is

made

to

supply

a 208-240

volt

power

source

for

use

with

external chemical

supply

injection

systems. These

connections

are also fused

with

a separate fuse in each line

of

this

208-

240

volt

supply.

All fuses used in MFS

machines

are

5mm

X

20mm

metric

fuses. Replace fuses

with

exact

replacement

only. Consult the

wiring

dia-

gram

that

comes

with

the

machine

for

proper

fuse sizes. Never use oversized fuses.

CONTROL TRANSFORMER

The

controls

are isolated

from

the 3 phase

line

by

the

control

transformer.

The

transforme(s

primary

(input) is

connected

to

two

of

the

three 3 phase lines.

The

second-

ary (output) is

connected

to

the

controls

and

the

frame

of

the

machine. The

transformer

is

rated at 250 VAC.

As connected,

the

transformer

has a 1: 1 ratio

with

the

secondary

voltage

typically

measur-

ing

approximately

the same as

the

incoming

3 phase line voltage.

16009607 Section

2.

Service Procedures

The

control

transformer

is

protected

by

two

fuses in

the

primary

and

a single fuse in

the

secondary.

OUT-OF-BALANCE SWITCH

Operation:

A

normally

closed

switch

is used

to

monitor

movement

of

the

tubs. This

switch

is a

"joy-

stick"

switch

in

which

enough

deflection

in

any

direction

will

cause

the

circuit

through

the

switch

to

open. The

operating

"shaft"

of

the

Balance

switch

is a steel spring. A

"lim-

iter

plate"

is

positioned

away

from

the

switch

so

that

the

outer

end

of

the

switch

shaft is

centered

in

the

limiter

plate

opening.

The

limiter

plate is secured

to

the

outer

shell and

moves

with

the

shell. Excessive

out

of

balance

will

cause

the

shell (outer tub)

to

move,

causing

the

limiter

plate

to

deflect

the

balance

switch

shaft

enough

to

open

the

switch

contacts. See

Figure

2-4.

1.

Facia panel

of

the

drum

2.

Limiter

3.

Rubber busing

4.

Bottom

of

the switch-

board

5.

Out-of-balance switch

6.

Adjustment

nut

7.

Switch

holder

Figure

2-4

Both

the

balance

switch

position

and

the

limiter

plate

position

may

be

moved

to

allow

adjustment

to

the

sensitivity at

the

balance

trip

point.

Adjustment:

The

following

adjustments

are

recommended

and

should

be checked as

part

of

the

maintenance.

•

Remove

the

panel

of

the

washer

to

gain

access

to

the

balance

switch

components.

• Begin

by

adjusting

the

limiter

(plate

with

hole

in it)

to

center

the

balance

switch

shaft (spring) in

the

limiter.

Secure

the

limiter

mounting

bolts.

•

The

distance

from

the

limiter

to

the

switch

body

should

be 100

mm

(about

4 inches).

Use

the

balance

switch

mounting

nuts

to

move

the

switch

to

the

front

or

back

for

this

adjustment.

• The

"sensitivity"

of

the

balance

switch

is

adjusted

by

moving

the

switch

holder

(and

the

switch)

to

the

left

or

right

to

change

the

trip

point.

In

most

cases

the

balance

assembly

is

adjusted at

the

factory

and little

if

any adjust-

ment

will

be needed.

OVERFLOW

The

machine

has overfill

protection

via the

overflow

system. The

overflow

system

consists

of

a

nipple

fitting

in the back

of

the

shell

assembly

(outer tub),

overflow

hose,

and nipple

fitting

on the drain

outlet

connection.

In

case

of

overfill,

water

is

routed

from

the

overflow

nipple

fitting

(note: the

overflow

outlet

is located several inches

higher

than

the

normal

fit

height

in the shell assembly)

and

out

the drain. The

outlet

of

the

overflow

hose

connection

is on the

outlet

side

of

the

drain valve and

allows

the

overflow

to

work

even

if

the drain is closed.

VENTS

There are

two

vents

located on the MFS

model

machines. The vents are used

as

an

air break

for

the

soap

compartment

and

outer

tub. The

purpose

of

the

vents

are

to

prevent

an

air

tight

compartment

from

siphoning

and/

or

to

prevent

contaminated

water

from

entering a fresh

water

supply. Vapors

from

hot

water

may

escape

from

the

vents

into

the

atmosphere.

Use caution

in

this

area due

to

the

possibility

of

hot

vapors.

Generally all

vents

exit

at

the

rear

the

ma-

chines. On

larger

MFS

models,

the

soap

16009607 Section

2.

Service Procedures

Maytag MFS25PN User manual

Popular Washer manuals by other brands