Mollet LF20 Operating Instruction

M LLET

Füllstandtechnik

Yo-Yo sensing level measurement

GmbH

continuous level indication for bulk solids

Operating instruction

Index

Safety instructions | Special conditions for ATEX-devices | Use . . . . . . . . . 02

LF

Page

. . . . . . . . . . . . . .

Data of manufacturer | Incoming goods inspection and storage | Identification . . . . . . . . . . . 03

Data of measuring devices | Technical data | Electrical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 04

Dimensions | Connecting flange . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 05

Sensing weights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 06

Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 07

Assembling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 08

Electrical connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Commissioning | Parameterisation | Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Returns | Disposal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

MOLLET D-74706 Osterburken Tel. [phone] Fax [phone] Operating instruction

04/14 © by MOLLET LF-BA-01 01

Yo-Yo sensing level measurement

M LLET

Füllstandtechnik

GmbH

Please, read and obey these safety instructions and the complete operating manual.

Safety instructions

1.

The installation, initial operation and maintenance must be done by a qualified expert with electrical know-how.

1.1

1.2 Check before installation whether the measuring device is in compliance with the specification of the point of
measurement like process and ambient temperature as well as the measuring range and whether the sensing weight
is suitable for the bulk solids.

1.3 For the electrical connection take notice of the local and statutory rules and regulations and/or the VDE 0100.

1.4 Consider the data of the name plate on the device.

1.5 A fuse (with max. 6 A) has to be connected in series to the voltage supply.

1.6 Protect the signal contacts from voltage peaks when inductive loads are connected.

1.6 Check the cable entry, cable gland and clamping nut, to see if they are sitting correctly and are sealed.

1.7 Put the device into operation only when the unit is closed and the cover sealing is intact.

LF20

1.8 The sensing weight must not sink into the bulk good surface and must not slip away at the angle of repose or
removal funnel.

1.9 Switch off the power supply, before opening the device (touch dangerous voltage).

1.10 Changes and repairs of the device are allowed only in so far as it is permitted in the operating instructions.

Prior to the use of the device in potentially explosive atmospheres please, read and obey the

Special conditions and guidance for safe use

in the attached

Explosions protection information

and note the operation instruction.

2. Use of the device

2.1 Intended use

- The device is used for cyclical level measurement of bulk solids with a density of >0.02 t/m³ in bunkers or silos.

2.2 Normal operation

- Please operate the measuring device only according the intended use.

- Use the measuring device only within the specified temperature ranges for process and ambience.

- Protect the electronics compartment against pollution.

- In case the measuring device becomes damaged, please stop operation immediately.

2.3 Improper use

- Ignoring safety regulations and operation instruction.

- Operation of the measuring device in inappropriate use.

- Installation of spare parts that are no original parts.

- Removal, addition or modification of components as far as it is not described in the documentation of the manufacturer.

- Violation of applicable standards and laws.

02 LF-BA-02 04/14 © by MOLLET

Operating instruction MOLLET D-74706 Osterburken Tel. [phone] Fax [phone]

M LLET

Füllstandtechnik

GmbH

Yo-Yo sensing level measurement

LF20

3. Data of manufacturer

Manufacturer MOLLET

Adress Industriepark RIO 103

Name of part MOLOSbob

Typ LF20- ...

Füllstandtechnik GmbH

74706 Osterburken
Germany

YO-YO sensing level measurement

5. Identification

Housing with 2 compartments

1.

Motor and electronics

2. Spool with measuring tape

Connecting flange

Sealing cuff

Wiper

Tape border

Sensing weight mounting

Buckling protection chain

Rotating bush

Sensing weight

4. Incoming goods inspection and storage

4.1 Incoming goods inspection

- Please check whether packaging or content are damaged

- Please check whether the supplied goods are incomplete or do not comply the
requirements as set out in your order.

4.2 Storage

-.For storage and transportation the measuring device has to be packed shock­resistant.

- Temperature range for storage -40 °C ... +60 °C

Certifications, certificates, approvals
A Standard = B conform and IP67
B ATEX W II 1/2D Ex ta/tb IIIC T99°C
Y Further approvals

Housing
8 Standard Aluminium coated RAL 7001, lid Aluminium nature
0 Special coating

Measurement range
4 Standard 15 m tape, stainless steel 1.4310
5 32 m tape, stainless steel 1.4310
8 42 m tape, stainless steel 1.4310

Wiper, maximum nozzle height
A Standard - wiper 230 mm Aluminium / steel
B Wiper 230 mm stainless steel 1.4301
C Wiper 500 mm Aluminium / steel
D Wiper 500 mm stainless steel 1.4301
E Wiper 1000 mm Aluminium / steel

F Wiper 1000 mm stainless steel 1.4301

Supply voltage
1 Standard 90 V AC ... 253 V AC, 50/60 Hz
3 20 V DC ... 28 V DC

Output
A Standard 0/4 ... 20 mA adjustable and 2 relay outputs
C 0/4 ... 20 mA adjustable and 4 relay outputs
Y Special version

Ambient temperature
D Standard -20°C ... +60°C
E -40°C ... +60°C with heating (ATEX II 1/2D -35 °C)
F -20°C ... +60°C with extended climate resistance
Y Special version

Process temperature
1 Standard = -20°C ... +60°C
2 -20°C ... +150°C
9 Special version

Dust

1

)

Sensing weights
A w/o sensing weight
B Normal weight, steel
C Normal weight, stainless steel 1.4571
D Umbrella / steel weight

E Umbrella / stainless steel weight 1.4571
G Medium bag, Polyester
N Plastics weight, PVC and steel
X Float gauge, stainless steel 1.4571

Additional equipment
1 Standard (no additional equipment)
2 Window and start push button
9 Special version

1

)

1

)

1

)

1

) not available for use in

potentially explosive atmospheres

MOLLET D-74706 Osterburken Tel. [phone] Fax [phone] Operating instruction

3

1

4

2

5 6

7

8 9 10

Order code

04/14 © by MOLLET LF-BA-03 03

M LLET

Füllstandtechnik

6. Data of measuring device

GmbH

Yo-Yo sensing level measurement

LF20

6.1 Technical data

Materials Housing Aluminum die casting, coated RAL 7001

Housing lid Aluminum AlMgSi1

Process connection Aluminum die casting

Tape Stainless steel 301, modified

Wiper Aluminum/Steel

or Stainless steel 304

Sensing weights

Normal weight 9.B Steel
Normal weight 9.C Stainless steel

Umbrella 9.D Polyester and steel

Umbrella 9.E Polyester and stainless steel

Medium bag 9.G Polyester and stainless steel

Plastics weight 9.N Plastics and steel )

Weight w/o sensing weight 10 kg

with sensing weight 11.5 kg

Dimensions 300 x 260 x 225 (HxBxD)

Angle of inclination max. 2°

Protection type IP67

Maintenance approx. after 45,000 measuring cycles

1

) not available for use in potentially explosive atmospheres

IP

316Ti

316Ti
316Ti

1

6.2 Application data

Ambient temperature 7

with heater -40 °C ... +60 °C

ATEX-device with heater 7.E -35 °C ... +60 °C

Process temperature 8. -20 °C ... +70 °C

with heater 7.E -40 °C ... +70 °C

ATEX-device with heater 7.E -35 °C ... +70 °C

.D -20 °C ... +60 °C ( )

7.E

1

8.2 -20 °C ... +150 °C

Standard

1

)

( )

Standard

1

)

1

)

amp

T

(Process)

T

6.4 Electrical data

Supply voltage 90 ... 253 V 50-60 Hz

Power consumption AC = 150 VA DC = 150 W

with heater 7.E AC = 170 VA DC = 170 W

Terminals max. 2.5 mm²

Cable entry 3x screwing M20x1.5 (6 ... 13 mm)

Signal inputs 2 available for external start or lock

Signal outputs active 0/4 ... 20 mA current output,

Relay outputs 2 relay outputs ( )

optional 6.C 2 additional relay outputs

Selectable relay functions

Counting pulse Pulses according tape length rolled out

Reset pulse Pulse before every new measurement

Gating of counting pulse Pulse during running up the sensing

Measurement active Pulse during active measuring cycle,

End of measurement Pulse when sensing weight reached

Service interval Information on required maintenance

5.1 (AC)

or 5.3 20 ... 28 V (DC)

measurement

active Input voltage range of an external control

12 ... 24 V DC

passive Connection of an external command unit,

e.g. switch, key, relay contact
(Start pulse length: min. 200 ms)

working resistance max. 600

Standard

e.g. to reset an external counter

weight, e.g. to hide counting pulses

e.g. to lock a filling device in order to
protect the sensing weight from being
covered by medium

upper end position

Alarm Output of fault states

Supply

Ω

Process pressure

1

) not available for use in potentially explosive atmospheres

- 0.5 bar ... 1 bar

p(Process)

6.3 Technical measuring data

Tape length 3 4 15 m

Tensile force max. 150 N

Tape run-off speed 0.16 ... 0.25 m/s

Measuring accuracy ± 2.5 cm or ± 1 Impuls

Highest measurable point Calculated from the block distance

plus a minimum run-out length of 20 cm

The individual value of the block distance is preset when delivered
and has only to be adjusted when the sensing weightis replaced.

04 LF-BA-04 04/14 © by MOLLET

.

3.

5 32 m

3.

8 42 m

(independent of selected measuring distance)

Operating instruction MOLLET D-74706 Osterburken Tel. [phone] Fax [phone]

Contact load 250 VAC, 6 A

Silver-cadmium-oxid contacts, gold plated

Optocoupler output for counting pulse

(optional when 4 relay are selected)

Loading capacity U max. 30 V DC, I max. 10 mA

Break down information recallable via following interfaces

Local display Error symbol

Error code with plain text dispaly

Current output State programmable:

Minimum

Current value <= 3.6 mA (4 - 20 mA) or
Current value 0 mA (0 - 20 mA)

Maximum

max. current value +10% (=22 mA)

Relay output Alarm function

M LLET

Füllstandtechnik

6.5 Dimensions

260

205

GmbH

100

Yo-Yo sensing level measurement

LF20

225

30

220

300

146

100

„X“

6.6 Process connection flange view „X“

160

20

230

Standard wiper 4.A, 4.BExtended wiper 4.C, 4.D or 4.E, 4.F

9518

MOLLET D-74706 Osterburken Tel. [phone] Fax [phone] Operating instruction

156

Lk 180

186

515 or 1015

04/14 © by MOLLET LF-BA-05 05

Yo-Yo sensing level measurement

M LLET

Füllstandtechnik

GmbH

6.7 Sensing weights

!!! Select a sensing weight that will not sink into the bulk good surface and will not slip away at the angle of repose or removal funnel.

LF20

Normal weight, o

Steel/stainless steel

For granulates and compacted bulk solids.

Bulk density >0.3 t/m³
Angle of repose steep with spike

The spike avoids slipping or tilting of the
sensing weight on a steep bulk surface.

Spike (screw-off)

rder code 5.B/5.C

for temperatures up to +150 °C

flat w/o spike

Ø55

Bag weight

Polyester and stainless steel

For granulates and compacted bulk solids.

Bulk density >0.2 t/m³
Angle of repose flat

~ 515

110110

Ø8

022-0207

Avoids damage of
outlet devices.

The bag is filled with the respective medium stored in the bunker or silo.

, order code 5.G

for temperatures up to +150 °C

~ 300

Ø ~ 150

022-0208

Plastic weight

PVC and steel

For granulates and compacted bulk solids.

Bulk density >0.3 t/m³
Angle of repose flat

, order code 5.N

for temperatures up to +70 °C

Ø80

230

~ 525

022-0209

Umbrella weight

Steel/stainless steel and Polyester

For very light and loose bulk solids.

Bulk density >0.02 t/m³
Angle of repose steep with spike

A large square surface prevents
it from deeply sinking into
the bulk solid.

, order code 5.D/5.E

for temperatures up to +150 °C

flat w/o spike

Spike
(screw-off)

Ø8

~ 525

115105

Not available for use in potentially explosive atmospheres.

06 LF-BA-06 04/14 © by MOLLET

Operating instruction MOLLET D-74706 Osterburken Tel. [phone] Fax [phone]

Edge length 400

022-0210

Yo-Yo sensing level measurement

M LLET

Füllstandtechnik

GmbH

7. Installation

7.1 Place of installation - Slope 7.3 Planing of place of installation

100 % full

*)

*)

Slope

022-0202

*)

X %

*)

Y %

0 % empty

Observe size and position of angle

*)

of repose and removal funnel

LF20

- Observe size and position of angle of repose and removal
funnel. Select a measuring point that is approximately in the
middle of the slope.

- Keep enough distance between measuring tape and internal
fixtures and fittings in order to avoid contact when the sensing
weight is oscillating.

- Select the mounting position on the bunker or silo roof in such a
way that falling bulk goods during filling or collapsing cornices
cannot spill the sensing weight and cannot damage the measuring
tape.

-

7.4 Installation nozzle

- The device is best mounted on a nozzle with a horizontal
counter flange
a flange with the same connection conditions.

- The minimum internal diameter of the nozzle has to be 95 mm.

- The length of the nozzle comply with the length of the wiper.
e.g. Wiper 230 mm  nozzle length 230 mm.

- Sensing weight has to be outside of the nozzle in the uppermost
position when measuring tape is completely wound up.

DN100 PN16 (dimensions acc. to EN 1092-1) or

Ø220

Lk180

(<2°)

< 2°

7.2 Place of installation - distances and nozzle

 Ø95

Distance Distance

Stream of bulk material

Measuring distance

< 2°

Cornices

4xØ18

Select length of the nozzle in
such a way that the sensing
weight poke out of the nozzle.

 Ø95

-

7.5 Installation nozzle for +150 °C

- For the process temperature range
wiper and nozzle have to be at least 500 mm long.

Ambient temperature

-20 °C  Ta  +70 °C

500 mm

022-0701

-20 ... +150 °C (option 8.2)

Installation nozzle

Wiper 500 mm

Process temperature

022-0218

MOLLET D-74706 Osterburken Tel. [phone] Fax [phone] Operating instruction

-20 °C  Ta  +150 °C

Sensing weight

022-0702

04/14 © by MOLLET LF-BA-07 07

M LLET

Füllstandtechnik

8. Assembling

Wiper

Tape border

GmbH

Yo-Yo sensing level measurement

LF20

8.1

Assembling sensing weight

- Sensing weight is delivered preassembled including rotating bush
and buckling protection chain.

- Fix the sensing weight on-site at the tape border with the screws
provided.

Buckling
protection
chain

-

Hook rod

Rotating bush

Normal sensing weight

Spike

Access hatch

8.2 Assembling LF20

- First put a sealing ring on top of the flange.

- Insert the sensing weight carefully through the nozzle into the silo
or bunker.

- Put now the measuring device on top of the flange.

- Observe the position of the cable entry for the electrical
connection.

- Assemble the device horizontal and fix it with four suitable
screws M16, plain washers and nuts.

-

8.3 Insert large sensing weights

- Normal weights, plastic weights and umbrella weights can be
insert into the silo or bunker through the installation nozzle.

- When using larger sensing weights, such as a filled medium bag
for example, a point must be present in the design of the bunker or
silo (e.g. access hatch) where these weights can be installed.

Maesuring tape

Lower carefully!

e.g. filled bag

08 LF-BA-08 04/14 © by MOLLET

Operating instruction MOLLET D-74706 Osterburken Tel. [phone] Fax [phone]

M LLET

Füllstandtechnik

8. Assembling

GmbH

Yo-Yo sensing level measurement

LF20

Transport fixture

8.4 Transport fixture

- Please remove the transport fixture in the tape spool compartment
as soon as the measuring device is fixed on top of the flange (see

)!

figure

- Unpredictable device reactions will occur, if this transport fixture is
not removed.

- Check the correct position of the cover sealing before you close
the cover.

-

8.5 Protection against dust

- In case of severe dust emission in bunkers or silos a compressed
air line can be connected above the mounting flange in order to
generate a slight over pressure.

- A G¼ bore is provided for this purpuse.

- Air volume as required.

Blind plug G¼

Connection for a
compressed air line

-

8.6 Check after assembling

- Are there any damages at the measuring device (visual check)?

Is the transport fixture in the tape spool compartment removed?

-

- Are the number of the measuring point and the labelling correct?

- Is there enough protection against ?

-

direct sunlight and heavy rain

8.7 Weather protection

- Protect the measuring device against direct sunlight and heavy

rain by using a weather protection cover or fit the protective hood
available as an accessory.

MOLLET D-74706 Osterburken Tel. [phone] Fax [phone] Operating instruction

04/14 © by MOLLET LF-BA-09 09

M LLET

Füllstandtechnik

9. Electrical connection

GmbH

Yo-Yo sensing level measurement

LF20

9.1 Potential equalization

- Connect the ground terminal on the housing to the local potential
equalization.

- Wire cross-section  2.5 mm².

- Use wire as short as possible.

-

Ground terminal

-

9.4 Position of terminals

Terminal 1

1 2

9.2 Potentially explosive dust atmospheres

Use devices with a valid

- W -marking only.

- For use of the device in potentially explosive atmospheres the
applicable national rules and standards have to be obeyed.
Always observe the explosion protection information and the
included safety instructions.

-

9.3 Check before electrical connection

The voltage supply must match the voltage specified on the name

­plate

.

- Switch off the voltage supply before connecting the device.

-

9.5 Electrical connection

For connection a basic installation cable is sufficient.

-

- Maximum wire cross-section for the terminals  2.5 mm².

Terminal

- To protect electrical circuits use electrical fuse with maximal 6 A.

2.2

2.1

1
2

3

3
4
5
6

7
8

9
10
11
12

Terminal

3.2

3.1

1
2
3
4
5

6

7
8
9

10

10 LF-BA-10 04/14 © by MOLLET

Operating instruction MOLLET D-74706 Osterburken Tel. [phone] Fax [phone]

M LLET

Füllstandtechnik

GmbH

Yo-Yo sensing level measurement

LF20

9. Electrical connection

Supply voltage AC

Circuit diagram - Terminal 1

1 2

1 2

N

5.1 90 ... 253 V (AC) 50-60 Hz

Relay output

Circuit diagram - Terminal 2.1

Contacts made of silver-cadmium-oxide, gold plated

1

[014] Relay­autput 1

2

3

3

PE

250 VAC, max. 6 A

For connection a basic installation cable is sufficient.

Supply voltage DC

Circuit diagram - Terminal 1

1 2

3

PE

5.3 20 ... 28 V (DC)

Relay output optional 6.C

Circuit diagram - Terminal 2.2

Contacts made of silver-cadmium-oxide, gold plated

7

[01B]

Relay-

autput 3

8

250 VAC, max. 6 A

3
4

[01A]

Relay-

autput 2

5

250 VAC, max. 6 A

6

The rest position matches with the position of the relays without power supply.

This represents the alert condition in case the function “alarm” is selected.

Signal inputs active Pulse lenght  200 ms

Circuit diagram - Terminal 3.1 and 3.2

1

12 ... 24 V DC

2

12 ... 24 V DC

3

The signal inputs active or passive can only be used alternatively.

A double connection from active and passive can not be used!

9

10

[01C]

Relay-

autput 4

11

250 VAC, max. 6 A

12

Signal inputs passive Pulse lenght  200 ms

Circuit diagram - Terminal 3.1 and 3.2

[012] Signal input 2[010] Signal input 1[012] Signal input 2[010] Signal input 1

6
7
8

1
2
3

6
7
8

Current output

Circuit diagram - Terminal 3.2

[033] Current output

Working resistance  600 Ω

9

0/4 ... 20 mA

10

MOLLET D-74706 Osterburken Tel. [phone] Fax [phone] Operating instruction

Optocoupler output optional 6.C

Circuit diagram - Terminal 3.1

U  30 V DC

I  10 mA

4

5

04/14 © by MOLLET LF-BA-11 11

001-0203

M LLET

Füllstandtechnik

GmbH

Yo-Yo sensing level measurement

LF20

10. Commissioning

10.1 Checks before commissioning

- Check whether the terminal assignment is correct.

- Check the tightness of the cable gland.

- Switch on the supply voltage.

measuring device will be operable, if the LCD-display is

- The
shining.

-

12. Maintenance

Wiper

Sealing cuff

Wiper plates

Wiper blocks

End guide

Measuring tape

M6x50

11. Parameterisation

11.1 Parameterisation

- Please undertake the parameterisation of the measuring device
by using the instruction for parameterisation.

- Close the housing with the cover after the parameterisation has
been finished.

External cleaning

12.1

Ensure that the cleaning agent used for externally cleaning does

­not attack the housing surface and seals.

Cleaning tape spool compartment

12.2

- The cleaning periods depend on the properties of the bulk solid.

-

In case of severe dust emission it is recommended to connect
a compressed air line above the mounting flange in order to
generate a slight over pressure (see chapter 8.5 Assembling).

Wiper check

12.3

To check the wiper you have to remove the LF20. To do so, please
note chapter 8 Assembling.

- Check whether the edges of the wiper blocks are still sharp
(round edges do no more clean the measuring tape correctly).

- If necessary please turn or substitute the wiper blocks.

- Check the end guide for cuts caused by the measuring tape.
If there are deep cuts, there will be a risk of measuring tape
jamming.

-

If necessary please substitute the end guide.

-

In case of abrasion please substitute the wiper plates.

- Check whether both wiper plates are securely in contact with the
measuring tape.

- Check whether the bellows are still in perfect condition and
replace in case of damages.

Tape border

12 LF-BA-12 04/14 © by MOLLET

Check of the measuring tape

12.4

- Check the measuring tape in regular intervals.

- If the visible part of the measuring tape is damaged, uncoil a

Measuring tape

Inlet guiding cone

section by manual [020] until it looks perfect.

Cut off the damaged parts and re-mount the sensing weight.

-

Do not cut off too much. Note the original length and the
measurement range required (silo height).

- If the measuring tape is damaged on a longer part, please replace
the entire measuring tape.

operation

12.5 Check of tape spool compartment

Check the tape spool compartment in regular intervals.

-

Buckling protection chain
with sensing weight

Operating instruction MOLLET D-74706 Osterburken Tel. [phone] Fax [phone]

- If the tape spool is damaged, please replace it.

- If the counting wheel is very sluggish to turn in spite of removed
tension of the measuring tape or in case it is damaged,
replace it.

- Please replace deteriorated or damaged cover seals.

Please refer to chapter 13 repair for details to dismantle the
LF20.

please

M LLET

Füllstandtechnik

13. Repair

GmbH

Yo-Yo sensing level measurement

LF20

13.1 Repair of Ex-certified devices

Ex-certified devices may only be repaired by

!!! MOLLET-

service team.

Counting wheel

Replacement of components

13.2

- Only original spare parts from MOLLET must be used.

- When ordering spare parts, please note the device designation on
the nameplate.

- Parts may only be replaced with the same parts.

-

Tape spool

Mounting screw
for tape spool

Mounting screw
for motor-gearbox
combination

Cover of tape spool
compartment

Tape border

Flange

Screws M5

Wiper

Measuring tape

Inlet guiding cone

Buckling protection chain
with sensing weight

Change of measuring tape

13.3

1. Move down the sensing weight at least 5 cm by using the

manual mode [020] in order to
tape

.

When using larger special sensing weights, the weight must
be lowered to an appropriate hatch (see 8.3 assembling).

2. Switch off and disconnect the supply voltage of the device.

3. Remove and/or expose the LF20 until the wiper and the

sensing weight are accessible. .

4. Remove the sensing weight including the tape border from the

measuring tape.

5. Unscrew the four screws on the tape spool.

6. Removed carefully the tape spool and the unwound part of the

measuring tape from the device.

7. A new tape spool is then installed in reverse order.

Change of wiper

13.4

The wiper can be replaced as soon as the device is prepared as

1.
described in chapter 13.3 change of measuring tape

2. Unscrew the three M5 screws at the flange of the wiper.

3. After that you will be able to take out the wiper.

Take care that during
measuring tape is positioned correctly in the wiper. The tape
must not be turned in tape spool compartment. In order to
check this open the cover of the tape spool compartment.

4. Mounting and dismounting in

remove tension of the measuring

mounting and dismounting the

reverse order.

.

MOLLET D-74706 Osterburken Tel. [phone] Fax [phone] Operating instruction

04/14 © by MOLLET LF-BA-13 13

M LLET

Füllstandtechnik

13. Repair

GmbH

Yo-Yo sensing level measurement

LF20

Motor-gearbox
combination

Cover plate

Return spring

Motor-gearbox
combination

C

BA

13.5 Change of drive unit

Move down the sensing weight a little bit by using the

1.

manual mode [020] in order to remove tension of the measuring
tape and the drive shaft.

2. Fasten the sensing weight or measuring tape.

Switch off and disconnect the supply voltage of the device

3. .

4. Unscrew mounting screws of the cover plates and remove them.

5. Disconnect the plug for the motor connector cable at the top
right of the motor-gearbox combination.

6. Unscrew mounting screw of the motor-gearbox combination on
the side of tape spool compartment (see figure page LF-BA-13).

7. Carefully remove the top PCB C (processor + display), you can
pull out the PCB for approx. 3-4 cm and put it on top of the
housing. (PCB is still connected to 2 flat cables)

8. Carefully hang out the return spring. The motor gearbox
combination can now be removed .

9. A new motor-gearbox combination has to be installed in reverse
order.

Mounting screw of the motor-gearbox combination has to

!!!

be installed with a copper washer

Cover plate

carefully

(ATEX).

14 LF-BA-14 04/14 © by MOLLET

Operating instruction MOLLET D-74706 Osterburken Tel. [phone] Fax [phone]

M LLET

Füllstandtechnik

13. Repair

GmbH

Yo-Yo sensing level measurement

LF20

13.6 Change of electronic and PCBs

- Note all parameters into the parameterisation instruction before
replacing the electronic or single PCBs.

- After the replacement of
setup has to be done and all parameters have to be re-inserted.

- The PCBs should only be replaced by a specialist.

- A precise description of the replacement process will be delivered
with every new piece of PCB, therefore such a description is not
provided at this point.

- When working with electronic components ensure that you have
sufficient ESD protection (protection against electrostatic
discharge).

- Only use the PCBs permitted for the device type when replacing
parts.

- The use of incorrect electronic parts may damage the device and
the Ex-certification will be lost.

the electronic or single PCBs a basic

14. Returns to the manufacturer

- Remove all residue of the bulk goods before returning the device
to the manufacturer

- Pay particular attention to seal grooves and scoring in which
residue of the bulk goods may stick.

That is of particular importance if the bulk goods poses a
risk to health, e.g. flammable, poisonous, corrosive or
carcinogenic.

- Please although specify:

• The chemical and physical characteristics of the bulk goods

• Description of the application

• Description of the error that has occurred

(when indicated, specify the error code)

• Operating period of the device

.

15. Disposal

- The level measurement device can be recycled.

- Disposal of the level measurement device is subject to the
environmental legislation of the respective country in effect for the
operator's premises and production conditions.

-

MOLLET D-74706 Osterburken Tel. [phone] Fax [phone] Operating instruction

04/14 © by MOLLET LF-BA-15 15

M LLET

Füllstandtechnik

GmbH

Yo-Yo sensing level measurement

LF20

16 LF-BA-16 04/14 © by MOLLET

Operating instruction MOLLET D-74706 Osterburken Tel. [phone] Fax [phone]