11 Ladder Service Trap

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Service Manual

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LFR/en/version:08/2007

MJFCIFSS

Chapter 11 - Ladder / Service trap systems

Access ladder and service trap ....................................................................................................................... 11-3

1 Schematics ....................................................................................................................................... 11-6

1.1 Hydraulic................................................................................................................................. 11-6

1.2 Electric.................................................................................................................................... 11-82 Location of components.................................................................................................................... 11-10

3 Functional description....................................................................................................................... 11-16

3.1 Electrical part.......................................................................................................................... 11-16

3.2 Hydraulic part ......................................................................................................................... 11-21

4 Troubleshooting................................................................................................................................ 11-23

4.1 Ladder .................................................................................................................................... 11-23

4.2 Service trap ............................................................................................................................ 11-27

5 Adjustment instructions..................................................................................................................... 11-31

5.1 Adjustment of the pressure control valve ............................................................................... 11-31

6 Detailed component description ....................................................................................................... 11-32

6.1 Electro-hydraulic gear pump................................................................................................... 11-32

6.2 Rotating cylinder..................................................................................................................... 11-356.3 Removal of the hydraulic cylinder........................................................................................... 11-36

6.4 Pressure relief valve............................................................................................................... 11-37

6.5 Solenoid-valve ........................................................................................................................ 11-38


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Access ladder and service trap


MJFCIFSS

11 Access ladder and service trap

The ladder circuit and the service trap circuit are opened circuits.

They are supplied by the same Electro-hydraulic pump.

The most important components of this circuit are :

The Electro-hydraulic pump

The rotating cylinder for the ladder

The service trap lock cylinder

The ladder lock cylinder

The pressure relief valve PRV

Technical data

Electro-hydraulic pumpPump output

Max. displacement

Max. flow

Max. operating pressure

Rotating cylinder for the ladder

Max. operating pressure

Max. torque

kW

cm

l/min

bar

bar

Nm

HY / ZBR 1 / 2 NIA 2200 / 4 / 24 / 0 D 2002,2

2

7,5

110

DA-H 100 180D, S2623

210

2500


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The access ladder

The access ladder of the uppercarriage is electrically driven.

Before opearting the machine, the ladder must be fully raised to the uppercarriage and locked in place.

The ladder can be extended and retracted from the uppercarriage via the control box E1022_1, which is ins-

talled on the upper ladder section at the catwalk.

The service trap

To simplify the oil refilling procedure, the drain of major components on the uppercarriage are centrally con-

nected via a service center compartment.

They are :

the engine oil

the splitterbox

the two swing gears

the fuel tank

the hydraulic tank


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the reservoir for windshield washer fluid

the principal grease tank

the teeth grease tank

the Centinel tank (if this option is installed)

The service trap is electrically driven. It can be extended and retracted via the control box E1022_2, which is

installed at the bottom of the access ladder.


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Schematics

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11.1Schematics

11.1.1Hydraulic


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Schematics

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Schematics

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Pos.

CLL

CLS

CP3

COP1COP2

CSS

M10

P12

PRV

RCL

SP

Y64

Y65

Y66

Y67

Y68Y69

Y70

Y71

Description

Cylinder - lock ladder

Cylinder - lock service station

Collecting pipe - power pack

Control plate ladderControl plate service station

Cylinder - sevice station

Electrical motor

Electro-hydraulic pump / ladder and service trap

Pressure relief valve (110 bar)

Rotating cylinder ladder

Suction pipe

Solenoid valve principal ladder up

Solenoid valve principal ladder locking

Solenoid valve principal ladder unlocking

Solenoid valve principal ladder down

Solenoid valve trap door upSolenoid valve trap door locking

Solenoid valve trap door unlocking

Solenoid valve trap door down


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Schematics

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Schematics

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11.1.2Electric


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Schematics

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Pos.

A1008.1

A1008.4

A1008.5

A1020

B92

B100

B101

B105

B106

E16.5

E21

E22.4

E57

E1003

E1005E1022.1

E1022.2

E1037

E1039.1

E1039.2

F138

F139

F140

F144

F163

F164

H15.4

H67

H68

H69

H70

Description

Plate relay E1005

Plate relay E1022.1

Plate relay E1003

FSG plate

Temperature switch / electrical motor M10

Proximity switch / service trap up

Proximity switch / service trap locked

Proximity switch / ladder up

Proximity switch / ladder locked

Service lightening 18W batteries

Service flood light 70W upper of cabin

Warn light travel alarm / ladder

Service trap lightening

Power connection box

Cabin connnection boxConnection box / ladder control

Connection box / service trap control

Connection box / solenoid valves for ladder

and service trap

Emergency supper box / control valves

Emergency supper box / engine

100A fuse / service circuit supply

100A fuse / motor M10 supply

15A fuse / board

15A fuse / ladder and service trap

7,5A fuse / connection box E1022.2

7,5A fuse / connection boc E1023

Horn travel alarm / ladder

Indicator / ladder not in upper position

Indicator / ladder not locked, no movements

allowed

Indicator / service trap not in upper position

Indicator / service trap not locked, no move-

ments allowed

Pos.

K110

K113

K137

KT9

M10

S122

S125

S126

S127

S141

S155

S156S157

S158

S159

S160

S161

S162

X134

X310

X320

Y64

Y65

Y66

Y67

Y68

Y69

Y70

Y71

Description

Relay for motor M10

Relay / lightening

Relay / cut off service trap when service trap

not locked

Relay timer lightening

Motor / ladder and service trap

Switch control without safety / ladder and ser-

vice trap

Switch / upper of cabin lightening

Switch board / upper of cabin lightening

Switch timer / upper of cabin lightening

Switch elevation lightening

Switch / ladder up

Switch / ladder lockingSwitch / ladder unlocking

Switch / ladder down

Switch / service trap up

Switch / service trap locking

Switch / service trap unlocking

Switch / service trap down

Terminal block E1003

Kl31 / principal ground E1003

Kl31 / service ground E1003

Solenoid valve / ladder up

solenoid valve / ladder locking

solenoid valve / ladder unlocking

solenoid valve / ladder down

solenoid valve / service trap up

solenoid valve / service trap locking

solenoid valve / service trap unlocking

solenoid valve / service trap down


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Location of components

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11.2Location of components

Connection box E1022.1 (ladder control) Connection box E1022.2 (trap control)


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Connection box E1037 for solenoid valves

Power connection box E1003 under the cab


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Service trap components


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Rotating cylinder RCL

Rotating cylinder RCL


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Hydraulic system of the ladder


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Functional description

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11.3Functional description

11.3.1Electrical part

11.3.1.1Ladder

Ladder up motion

The ladder up motion is driven electrically via a remote control, or via the push button S155on the control box

E1022-1.

The solenoid valveY64is supplied via the plate A1008-4and E1037.

The relay K110 for M10 is supplied via the plate A1008-5.

If the temperature switch B92is opened (the temperature of the motor M10is too high), nothing hap-

pens.

If the temperature switch B92, is closed, the motor M10is supplied and it drives the pump P12. The

rotating cylinder RCLof the ladder is supplied. The ladder goes up. The relay B02in the plate A1008-5is switched and then the warm light alarm E22-4and the horn alarm

H15-4are in motion while the button S155is pushed.

When the ladder is coming near its upper position, its movement is automatically broken thanks to a sys-

tem included in the rotating cylinder (see components).

The proximity switch (ladder in upper position) is not in motion.

The indicator H67(ladder not in upper position) is on.

The switch S156(ladder locking) is not supplied.

The proximity switch B106(ladder locked) is not in motion.

The indicator H68(ladder not locked) is on.

No current is sent to the plate A1008.5(the excavator can not be actuated).

Ladder in upper position

When the ladder has reached its upper position, the proximity switch B105is in motion.

The relay B01in the plate A1008-4is switched.

The indicator H67(ladder not in upper position) is switched off.

The switch S156(ladder locking) is supplied.

Ladder locking

The ladder locking is driven electrically via a remote control, or via a the push button S156on the control box

E1022-1(see connection box E1022.1(ladder control)).

As the proximity switch B105is in motion, the solenoid valveY65is supplied via the plate A1008-4and

E1037(as the ladder is in upper position, it can be locked). The relay K110for M10is supplied via the plate A1008-5and the connector X134.

If the temperature switch B92is opened (the tempereture of the motor M10is too high), nothing hap-

pens.

If the temperature switch B92is closed, the motor M10is supplied and it drives the pump P12. The

locker cylinder CLLof the ladder is supplied. The ladder is locking.

The relay B02in the plate A1008-5is switched and then the warm light alarm E22-4and the horn alarm




No current is sent to the plateA1008.5(the excavator can not be actuated).


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Ladder locked

When the ladder is locked, the proximity switch B106is in motion.

The relay ST1in the plate A1008-4is switched.

The indicator H68(ladder not locked) is switched off.

A current is sent to the plate A1008.5.

The relay B02in the plate A1008-4is switched.The switch S158(ladder descending motion) is not supplied.

The solenoid valveY67which controls the ladder descending motion can not be supplied anymore

: as ladder is in locked position, it can not go down.

Ladder unlocking

The ladder unlocking is driven electrically via a remote control, or via the push button S157on the control box

E1022-1(see connection box E1022.1(ladder control)).


The relay K110for M10is supplied via the plate A1008-5and the connector X134.


pens.If the temperature switch B92is closed, the motor M10is supplied and it drives the pump P12. The

locker cylinder CLLof the ladder is supplied. The ladder is unlocking.

The relay B02in the plate A1008-5is switched and then the warn light alarm E22-4and the horn alarm


Ladder unlocked

The proximity switch B106is not in motion anymore.

The relay ST1in the plate A1008-4is not switched anymore.

The indicator H68is switched on.


The relay B02in the plate A1008-4is not switched anymore.

The solenoid valveY67that controls the ladder descending motion can be supplied.

Ladder descending motion

The ladder descending motion is driven electrically via a remote control, or via the push button S158on the

control box E1022-1(see connection box E1022.1(ladder control)).

As the proximity switch B106is not in motion, the solenoid valveY67is supplied via the relay B02in the

plate A1008-4and E1037(as the ladder is not locked, it can be lowered).


If the temperatue switch B92is opened (the temperature of the motor M10is too high), nothing hap-

pens.


rotating cylinder RCLof the ladder is supplied. The ladder goes down. The relay B02in the plate A1008-5is switched and then the warn light alarm E22-4and the horn alarm


When the ladder is coming near its low position, its movement is automatically slowed down thanks to a

system included in the rotating cylinder (see components).

The proximity switch B105(ladder in upper position) is not in motion.

The indicator H67(ladder not in upper position) is on.

The switch S156(ladder locking) is not supplied.





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11.3.1.2Service trap

Trap unlocking

The trap unlocking is driven electrically via a remote control, or via the push button S161on the control box

E1022-2(see connection box E1022.2(trap control)).




pens.


locker cylinder CLSof the trap is supplied. The trap is unlocking.



Trap unlocked

The proximity switch B101is not in motion anymore.

The relay ST1in the plate A1008-5is not switched anymore.The indicator H70(service trap not locked) is switched on.

The current issued of the relay ST1in the plate A1008-4can not be sent to the FSGplate A1020

(the excavator can not be actuated).

The relay K137in E1003is not switched anymore.

The solenoid valveY71, which controls the service trap descending motion, can be supplied.

Trap descending motion

The trap descending motion is driven electrically via a remote control, or via the push button S162on the control

box E1022-2(see connection box E1022.2(trap control)).

As the proximity switch B101is not in motion, the relay K137is not switched and then the solenoid valve

Y71is supplied via the relay K137and E1037(as the trap is unlocked, it can be lowered). The relay K110for M10is supplied via the plate A1008-5and the connector X134.


pens.


cylinder CSSof the trap is supplied. The trap goes down.



When the trap is coming near its low position, its movement is automatically slowed down thanks to a sys-

tem included in the cylinder (see components).

The proximity switch B100(trap in upper position) is not in motion.

The indicator H69(trap not in upper position) is on.

The switch S160(trap locking) is not supplied.

The service trap lightening E57is on.

The proximity switch B101(trap locked) is not in motion.

The indicator H70(trap not locked) is on.



Trap up motion

The trap up motion is driven electrically via a remote control, or via the push button S159on the control box




If the temperature switch B92is opened (the temperature of the motor M10is too high), nothing hap-pens.


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cylinder CSSof the trap is supplied. The trap goes up.



When the trap is coming near its upper position, its movement is automatically slowed down thanks to a

system included in the cylinder (see components).

The proximity switch B100(trap in upper position) is not in motion.The indicator H69(trap not in upper position) is on.

The switch S160(trap locking) is not supplied.

The service trap lightening E57is on.





Trap in upper position

When the trap has reached its upper position, the proximity switch B100is in motion.

The relay B01in the plate A1008-5is switched. The indicator H69is switched off.

The service trap lightening E57is no more supplied.

The switch S160(trap locking) is supplied.





Trap locking

The trap locking is driven electrically via a remote control, or via the push button S160on the control box


As the proximity switch B100is in motion, the solenoid valve Y69is supplied via the plate A1008-5and

E1037(if the trap is not in upper position, B100is not in motion andY69can not be supplied).



pens.


locker cylinder CLSof the trap is supplied. The trap is locking.



Trap locked

The proximity switch B101is in motion.

The relay ST1in the plate A1008-5is switched.

The indicator H70(service trap not locked) is switched off.

The current issued of the relay ST1in the plate A1008-4can now be sent to the FSGplate A1020.

The relay K137in E1003is switched.

The solenoid valveY71which controls the trap descending motion can not be supplied anymore: as

the trap is in locked position, it can not go down.


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11.3.1.3Safety measure

The excavator can only be operated if the ladder and the service trap are locked in their upper position. It

means that if the proximity switches B106and B101are not in motion, no movements are allowed.

When the ladder is locked, the proximity switch B106is in motion. The relay ST1in the plate A1008-4is

switched and sends a current to the plate A1008.5.

When the trap is locked, the proximity switch B101is in motion. The relay ST1in the plate A1008-5isswitched. The current issued of the relay ST1 in the plate A1008-4can now be sent to the FSGplate

A1020.

While the FSGplate A1020receives no current, no movements are possible.

This safety measure can be bypassed momentarily by pushing and holding the switch S122.

By pushing S122, a current will be directly sent to the FSGplate A1020and the excavator will be able to be

operated.


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11.3.2Hydraulic part

The hydraulic part consists in :

The pump P12(which is driven by the motor M10)

The solenoid valvesY... which control the movements.*

The pressure relief valve

The cylinders CLL(ladder lock), CLS(trap lock) and CSS(trap motion). The rotating cylinder RCL(ladder motion).

The pressure relief valve limits the pressure value at 110 bar in order to prevent the mechanical damages.

This figure shows the hydraulic schematic of the ladder descending motion.

The pump P12supplies the port Bof the rotating cylinder RCLthrew a non-return valve. Then the oil flows to

the brake valve. While the pressure issued of the rotating cylinder is not sufficiency, the oil can not flow to the

collecting pipe CP3: the ladder does not move. When the pressure is sufficiently strong, the brake valve allows

to control the speed of the ladder down motion and so to prevent that the ladder falls abruptly due to its weight.


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This figure shows the hydraulic schematic of the ladder up motion.

The pump P12supplies the port Aof the rotating cylinder RCLthrew a non-return valve. Another part of the oil

opens the non-return valve. The oil flows out the rotating cylinder and flows to the collecting pipe CP3through

the non-return valve, which has been opened by the high pressure.


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Troubleshooting

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11.4Troubleshooting

11.4.1Ladder

Problem : the ladder does not go up.

-

-

When you press the button S155that controls the ladder up motion, the ladder doesnt go up.

Does the motor M10work?

Y N

- The problem is coming from the electric part :

The temperature switch B92detects a too high temperature of the

motor M10, wait until the motor is cold enough.

The fuse F139is not in service condition.

The temperature switch B92is defective. The relay K110is not supplied (broke wire or connector) or is de-

fective.

- Verify if the led corresponding to the solenoid valveY64on the connection box E1037is on when

you push the button S155.

Y N

- The button S155or the wire between S155and E1037is broken.

-

-

The solenoid valveY64is defective or is not supplied (broken wire between E1037andY64).

Control the adjustment value of the pressure control valve. Is the value set at 110 bar?

Y N

- Adjust the pressure control valve (see adjustment of the pressure control valve).

- One or several components of the rotating cylinder RCLare defective.


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Troubleshooting

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Problem : the ladder can not be locked

-

-

When you press the button S156that controls the ladder locking, the ladder gets not locked.

Is the indicator H67(ladder not in upper position) off?

Y N

- Push the button S156until the ladder has reached its top position.

The ladder can now be locked.

- Does the motor M10work?

Y N





The temperature switch B92is defective.

The relay K110is not supplied (broke wire or connector) or is de-fective.



Y N


The proximity switch B105(ladder in upper position) is not sup-

plied (broken wire or connector) or is defective.

The relay B01in A1008_4is defective.

The button S156or the wire between S156and E1037is broken.

- Change the faulty electric components.

-

-



Y N


- The lock ladder cylinder CLLis defective or is blocked by an intruding object.


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Problem : ladder can not be unlocked

-

-

When you press the button S157that controls the ladder unlocking, the ladder gets not unlocked.


Y N






The relay K110is not supplied (broke wire or connector) or is de-

fective.



Y N


-

-



Y N


- The lock ladder cylinder CLL is defective or is blocked by an intruding object.


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Troubleshooting

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Problem : the ladder does not go down.

-

-

When you press the button S158that controls the ladder descending motion, the ladder doesnt go

down.

Is the indicator H68(ladder unlocked) on?

Y N

- Push the button S157until the ladder is unlocked.

The ladder can now go down.


Y N






fective.



Y N


The proximity switch B106(ladder locked) is defective.




-

-



Y N


- One or several components of the rotating cylinder RCLare defective. You can nevertheless make

the ladder go down by switching the valve on the rotating cylinder.


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11.4.2Service trap

Problem : the service trap can not be unlocked

-

-

When you press the button S161that controls the service trap unlocking, the trap gets not unlocked.


Y N







fective.



Y N


-

-



Y N


- The lock service trap cylinder CLSis defective or is blocked by an intruding object.


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Troubleshooting

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Problem : the service trap does not go down.

-

-

When you press the button S162that controls the service trap descending motion, the trap doesnt

go down.

Is the indicator H70(service trap unlocked) on?

Y N

- Push the button S162until the service trap is unlocked.

The service trap can now go down.


Y N






fective.



Y N


The proximity switch B101(trap locked) is defective.

The relay K137in A1008_5is defective.



-

-



Y N


- The service trap cylinder CSSis defective or is blocked by an intruding object.


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Problem : the service trap does not go up.

-

-

When you press the button S159that controls the service trap descending motion, the trap doesnt

go down.


Y N







fective.



Y N


-

-



Y N


- The service trap cylinder CSSis defective or is blocked by an intruding object.


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Troubleshooting

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Problem : the service trap can not be locked.

-

-

When you press the button S160that controls the service trap locking, the trap gets not locked.

Is the indicator H69(service trap not in top position) on?

Y N- Push the button S160until the service trap is in top position.

The service trap can now be locked.


Y N







fective.



Y N


The proximity switch B100(trap in top position) is defective or not

supplied (broken wire or connector).




-

-



Y N


- The lock service trap cylinder CLSis defective or is blocked by an intruding object.


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Adjustment instructions

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11.5Adjustment instructions

11.5.1Adjustment of the pressure control valve

Attach a 600 bar pressure gauge to the test point.

Actuate the down motion for the ladder or for trap.

When the ladder or the trap has reached its low position, continue to press the button.

Adjust the pressure relief valve (PRV) at 110 bar (see components description).

The cushioning adjustment of the rotating cylinder is described in chapter 6.


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Detailed component description

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11.6Detailed component description

11.6.1Electro-hydraulic gear pump

The electro-hydraulic gear pump P12supplies the ladder circuit and the service trap circuit.

11.6.1.1Description

The electro gear pump consists in two main parts :

The direct current motor.

The geared pump.

2

3

4

5

6

O-ring

Direct current motor

Plain washer

Hex. screw

Driver

7

10

30

31

32

High current relay

Hydraulic gear pump

Radial-lip-type oil seal

Carbon-brush set

Temperature switch


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11.6.1.2Function

The functioning principle of a geared pump is illustrated by the following drawing.

This pump is made of a leading gear (1) which drags a second gear (2) both located in a housing. The gears

rotate in opposite sense and engage on a point located on the aspiration and discharge opening axe (A-B). In

A the gears separate creating partial vacuum filled with hydraulic oil. The liquid is hold between the teeth and

the housing and transferred in B where it flows through B. The precise gear engagement secures the oil-ti-

ghtness between the aspiration and discharging opening and minimises the internal leakage.

11.6.1.3Maintenance and repair

Some oil leakage can be found at the gear pump. To replace the faulty seal kit, remove the screw 16and chan-

ge the defective seal kit.

The gear pump does not require further maintenance.


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3

5

10

1516

24

25

Oil seal

Spring clip

Seal kit

Spring ringHex. HD screw

Protecting cap

Locking plug


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11.6.2Rotating cylinder

11.6.2.1Functional description

The oil pressure that is supplied through connections P1and P2causes a rotary movement on the actuator

shaft. The linear movement of the piston Kis converted into a rotary movement by means of multiple helical

gears in the housing, piston and shaft.

11.6.2.2Cushioning end positions

The pressure medium displaced by piston (c) initially flows freely through the connecting hole (b) until piston

(c) completely closes the hole (b), thereby throttling the piston speed. After completely covering piston (c), the

medium can only escape through hole (a). The quantity flowing from ato bcan be regulate by the throttle screw

(d). When the pressure enters from the opposite direction the medium flows from bto a. The non-return valve

opens and there is an unimpeded flow at an into the cylinder space. The hole (b) is opened again the backs-troke of piston (c).

11.6.2.3Cushioning adjustment

After loosening the self-sealing lock nut, the throttle section can be adjusted by an Allen key.

Turn the tapered throttle valve screw right in and loosen it one turn. The fine adjustment of the cushioning can

now be made.


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MJFCIFSS

11.6.3Removal of the hydraulic cylinder

Turn the motor M10off.

Relieve the hydraulic lines by moving the servo control valve several times.

Secure the hydraulic cylinder with lift. If necessary, secure the attachment parts also.

Verify that no one can manipulate the trap or the ladder during the removal of those parts.

Attach the trap, if you change the service station cylinder CSS.

Remove the hydraulic hoses and catch the hydraulic oil in an appropriate container. If necessary, remove the

connector with hose from piston bearing and cylinder bottom.

When there is an oil leak in a hydraulic cylinder, check the seal kit.

1

2

3

Piston rod

Cylinder

Guide but

4

5

6

Piston

Seal kit

Hex. nut


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Service Manual

R 9250 from 13466


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MJFCIFSS

11.6.4Pressure relief valve

11.6.4.1Use

If the resistance, which acts against the load in a hydraulic system, were to rise to an undesirable and unac-

ceptable level, the weakest point in the hydraulic system would be destroyed. To prevent this, an artificial weak

point, a kind of circuit breaker (relief) is added. The object is locate this hydraulic component, which is initiallyheld in a closed position by adjustable spring pressure, so the fluctuating system of the whole hydraulic pres-

sure circuit can act on it. An increase in system pressure above the pressure setting of the relief valve lifts off

the poppet, ball or piston and directs the excess pressurised fluid, supplied by the pump but accepted by the

end user, back to the tank. The hydraulic energy produced in this converted into heat.

This hydraulic component is a pilot operated pressure limiting valve (primary valve).

These cartridges type, primary pressure relief valves in the control valve are located in front of the first piston.

A direct acting relief valve is installed as a control part in the pilot operated pressure relief valve, which triggers

an impulse to the second, larger valve. Both valves are normally open.

A characteristic of this valve is that once the valve has started to relieve and is contaminated, no further in-

crease in pressure is possible. This protects the system and damage to the components is avoided.

11.6.4.2Function

During operation, the system pressure pushes against the front side of piston 31.

The same pressure is simultaneously applied via orifice Aon the backside of piston 31, and via orifice Bto

poppet 33. Springs 32and 14move piston 31and poppet 33into closed position.

As soon as the system pressure exceeds the pressure setting of spring 14, the poppet 33is lifted off its seat,and some fluid escapes into the return line via orifice D. The previous static condition is now dynamic as fluid

is trying to flow via orifice Ain order to compensate the loss of volume and pressure. The size of the orifice

prevents immediate compensation, and a temporary difference in pressure between the upper and the bottom

of the main piston 31exists.

The difference in pressure causes the system pressure, which is still pushing against the front of the piston 31,

to lift the piston from its seat and large amounts of fluid can return to the tank via connection C.

11.6.4.3Pressure adjustment

To adjust pressure, remove cap 23, loosen lock nut 35and turn the adjustment screw 34clock - or counter-

clockwise to lower or raise the pressure. After the adjustment has been made, secure screw with lock nut (tor-

que to 10 Nm) and install a lead seal.


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Access ladder and service trap Service Manual



11.6.5Solenoid-valve

Note :before removing the solenoid-valve observe all safety requirements :

Turn the motor M10 off.

Relieve the hydraulic lines by moving the servo control valve several times.

Verify that no one can manipulate the ladder during the removal of the solenoid-valve.

11.6.5.1Description

The piston slide valve can move in different positions with the magnet Aor B. The pressure arrives from P, and

will go out from the hole Aor B(it depends in which position is the piston slide valve), and will feed in oil the

cylinders. The other hole (Aor B), evacuate the pressure oil which is coming back from the cylinders to the oil

tank T. The neutral position of the piston slide valve is set with return springs.

Date post:	22-Feb-2018
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11 Ladder Service Trap

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