Nilfisk-Advance SH TRUCK User manual

SH TRUCK -
Instructions for use
107319141 k (08.2015)
EN-DE-FR-NL-ES-IT-RU-PL-HU

Printed in Hungary
Copyright © 2015 Nilfisk A/S
Instructions for use ........................................................................................................................3 - 28
Betriebsanleitung.........................................................................................................................29 - 55
Manuel d’Instructions...................................................................................................................56 - 82
Gebruikershandleiding.................................................................................................................83 - 109
Manual de instrucciones............................................................................................................110 - 137
Manuale di istruzioni..................................................................................................................138 - 164
Руководство..............................................................................................................................165 - 191
Instrukcje dotyczące obsługi .....................................................................................................192 - 219
Üzemeltetési útmutató...............................................................................................................220 - 248

3
SH TRUCK
Original Instructions
Index
1 Safety Precautions and Warnings ................................................................................................4
2 Description .....................................................................................................................................5
2.1 Application................................................................................................................................5
2.2 Operation elements ..................................................................................................................5
3 Installation ......................................................................................................................................6
3.1 Temperature conditions ............................................................................................................6
3.2 Condition of distance................................................................................................................6
3.3 Foundation / leveling.................................................................................................................6
3.4 Water connection......................................................................................................................7
3.5 Mains power connection...........................................................................................................7
3.6 High-pressure connection.........................................................................................................8
3.7 Venting......................................................................................................................................9
3.8 Connecting to external fuel supply .......................................................................................10
4 Operation ......................................................................................................................................11
4.1 Connections............................................................................................................................11
4.2 Operation ..............................................................................................................................14
5 Fields of Application and Working Methods..............................................................................18
5.1 Fields of application................................................................................................................18
5.2 Working pressure ...................................................................................................................18
5.3 Temperature ..........................................................................................................................18
5.4 Mechanical impact..................................................................................................................18
5.5 Detergents..............................................................................................................................19
5.6 Working methods....................................................................................................................20
5.7 Typical cleaning tasks.............................................................................................................21
6 Maintenance .................................................................................................................................22
6.1 Hour counters.........................................................................................................................23
6.2 Oil ...........................................................................................................................................23
6.3 Water filter ..............................................................................................................................24
6.4 Cleaning of high pressure nozzle ...........................................................................................24
6.5 Fuel filter ................................................................................................................................24
6.6 Disposable waste ...................................................................................................................24
7 Trouble Shooting..........................................................................................................................25
7.1 General trouble shooting .......................................................................................................25
7.2 Error messages ......................................................................................................................26
8 Technical Data..............................................................................................................................27
9 Warranty........................................................................................................................................27
10 Declaration of Conformity ...........................................................................................................28

4
SH TRUCK
Original Instructions
1 Safety Precautions and Warnings
Symbols used to mark
instructions
Before starting up
your high-pressure
washer for the first
time, this instruc-
tion manual must
be read through carefully. Save
the instructions for later use.
Safety instruc-
tions marked with
this symbol must
be observed to
prevent danger to persons.
This symbol is
used to mark
safety instruc-
tions that must
be observed to
prevent damage
to the machine and its perfor-
mance.
This symbol
indicates tips and
instructions to
simplify work and to ensure a
safe operation.
High Pressure Washer -
SAFETY INSTRUCTIONS
107141898 D (07-2015)

5
SH TRUCK
Original Instructions
2 Description
This high-pressure hot water
washer has been developed
for stationary installation and
professional use within:
- light industry
- transport
- building and construction
- service
Section 4 describes how to use
the high-pressure hot water
washer.
Only use the high-pressure
hot water washer for purposes
described in this manual.
The safety precautions must be
observed to prevent damage
to the machine, the surface to
be cleaned or severe personal
injuries.
2.2 Operation elements See illustration at the end of
these operating instructions.
1 High-pressure outlet (quick
coupling, male)
2 Main switch
3 Stop push button (red)
4 Start push button (green)
5 Heating ON/OFF push
button
6 Pressure gauge
7 Water inlet
8 Thermostat (temperature
adjustment)
9 Button for addition of
detergents
10 Inspection window (hour
counters, error messages)
11 Holder for spray lance
12 Dosing of detergent
13 Data plate
14 Lifting device
15 Holder for spray lance -
frost protection, external
(option, not standard)
2.1 Application

6
SH TRUCK
Original Instructions
-AX#
-IN#
3 Installation
3.1 Temperature conditions The machine has been con-
structed for outdoor placement.
The min. ambient temperature
for the ma chine is –20°C and
the maximum ambient tempera-
ture is 40°C.
Note: Hose and spray lance are
not frost resisting as a standard
and must therefore be dis-
mounted at temperatures below
0°C.
3.2 Condition of distance
-INMM
-IN
MM
-INMM

3.3 Foundation / leveling Place the machine on a plane
floor.
Bolt the machine to the founda-
tion through the 3 holes (Ø12
mm) in the bottom plate. Before
fastening, the machine must be
leveled.
Shape of foundation, see fold-
out at the end of this manual.
In consideration of the cooling
system of the machine and the
accessibility of service, there
must be free wall space on both
sides of the machine. To the
right 200 mm at a minimum, to
the left 500 mm at a minimum
and behind 300 mm.
The distance from the chimney
outlet to inflammable material
must be 1,000 mm.
The chimney (1) can be turned
180° by dismounting 4 pcs. M5
screws (under the top plate),
turning the chimney and re-
mounting the screws.

7
SH TRUCK
Original Instructions

3.4 Water connection
The water connection is made
with a flexible hose connected
to the water tank (7) of the
machine.
The water hose can be lead in
through:
1. The bottom plate
2. The punch-out pieces in the
rear plate
(see foldout at the end of this
manual).
Make sure that the supply
hose is suited for the purpose
(temperature and flow rate). If
in doubt, contact your Nilfisk
representative.
The connection can be made to
a public drinking water supply
network or a private water sup-
ply. Water quality: particle size
<50  A shut-off cock should
be mounted on the water sup-
ply network in the immediate
vicinity of the machine. Make
sure that the water supply is
within the following specifica-
tions and that the water does
not contain particles such as
floating sand.
Min. water inlet pressure: 1 bar
(at the required flow rate of the
machine - see data plate.
Max. water pressure: 10 bar
Max. water inlet temp.: 30°C.
All SH TRUCK feature a water
tank, and no further protection
against back-flowing water into
the supply network is required.
The machine complies with EN
1717.
If there is a risk of floating sand
or other impurities in the inlet
water, a sand filter (50 micron)
should be mounted between the
supply outlet and the internal
filter of the machine.
3.5 Mains power connection
CAUTION! An
authorized electri-
cian must perform
the electrical
connection of the machine to
the main power supply. Refer to
section “1 Safety precautions
and warnings”.
The following precautions must
be observed:
 Make sure that the supply
cable is of the correct dimen-
sion (see voltage and load on
the data plate of the machine)
and is suitable for the specific
environment.

8
SH TRUCK
Original Instructions
The electric cable can be lead
in through:
1.The bottom plate.
2.The punch-out pieces in the
rear plate and through the re-
lief ring into the junction box.
(see foldout at the end of this
manual).
 Connect the phase cords of
the supply cable to the con-
nection terminals L1, L2 and
L3. Connect the zero cord to
N. For single phase machines
use L1 and N to connect
phase and zero cords.
 Connect protective earth wire
to the earthing terminal.
 Check and measure the
protective earth connection
according to legislation.
 Connect the other end of the
cable to an approved plugged
socket outlet of a correct
dimensioned main supply.
Make sure that the cable is
properly guided and relieved
between the fixed installation
and the machine and that the
cable is without any damage to
the insulation.
Also see notes in section
“1 Safety precautions and
warnings”!
3.6 High-pressure connec-
tion
The outlet of the machine (1)
can be connected directly to a
standard high-pressure hose
(a) or to a pipeline with fixed
outlet points (b).
IMPORTANT: When connect-
ing to a pipeline always use a
flexible hose connection from
the outlet of the machine (pos.
1) - order no. 6300843. Contact
your Nilfisk distributor for further
information.
It is recommended to let a ser-
vice technician authorized by
Nilfisk prepare the pipeline.
b

A
Note: Beware
that the electric
cables of the
machine are not
mixed up. The
wires 1, 2, 3,
4 MUST keep the illustrated
positions.

9
SH TRUCK
Original Instructions
d
c
ON
3
4
3.7 Venting
When the SH TRUCK is prop-
erly connected to supply water,
electrical installation and a
high-pressure hose (or pipeline)
the high-pressure pump must
be vented before it is opera-
tional.
1. Turn the main switch, (2)to
position “ON”.
2. Push the “START” button
(3), and the SH TRUCK will
start.
3. Open the outlet point (spray
handle on high-pressure
hose, (c) or outlet on piping
system (d) without having a
spray lance connected.
4. Let the water run until all air
has escaped from the pump
(even water flow).
5. In the case of a recently
installed piping system,
or if the pipeline and the
pump have been emptied in
any other way, the system
should be vented by starting
the pump and then letting
the water run at each outlet
point of the pipeline at turns.
It is recommended to begin
with the most distant outlet
(height and/or length).
6. When connecting the high-
pressure hose directly to
the machine, starting the
pump and activating the
trigger of the spray handle
without having attached the
spray lance, should vent the
system.
7. Stop the SH TRUCK by
pressing the “STOP” push
button (4).
The SH TRUCK is now vented.

10
SH TRUCK
Original Instructions
3.8 Connecting to external
fuel supply
2
Diesel stored externally for
more than 6 months is not
allowed to be filled into Nilfisk
high pressure cleaners.
Diesel EN 590 is not recom-
mended for use in HPW's at
an ambient temperature below
0°C.
Diesel EN 590 from an open
container must not be used.
You can choose between “one”
and “two” -string connection,
where “one”-string only has one
supply hose (a) and “two”-string
has an additional return hose
(b) - see figure.
Please observe that in some
countries only the “one” string
system is approved.
The fuel hose for the external
fuel supply can be lead-in:
1. Through the bottom plate to
the oil pump.
2. Through the punch-out
pieces in the rear plate to
the oil pump.
See foldout at the end of this
manual.
Please observe the following
restrictions to fuel line.
The SH TRUCK can be con-
nected to an external fuel sup-
ply. As a standard, the machine
is supplied with a 40 l container.
Heating oil, DIN 51603-1 (with-
out bio diesel) can be used.
Diesel according to EN 590 (up
to 7% bio diesel) can be used
with the following restrictions:
Maximum storage time in high
pressure cleaner diesel tank: 1
month.

11
SH TRUCK
Original Instructions
1
2
3

A
4 Operation
4.1 Connections
4.1.1 High-pressure hose -
directly on the machine
The Nilfisk high-pressure hose
with imprinted max. working
pressure and temperature
should be attached to the outlet
connection of the machine (1)
by the quick coupling (a).
Max. extension hose: 50 m.
Danger of scalding!
Never dismount high-pressure
hoses at water temperatures
above 50°C.
IMPORTANT: Prior to dis-
mounting the high-pressure
hose, the machine should be
stopped. Then activate the
trigger of the spray handle to
relieve the high-pressure hose
of pressure.
4.1.2 High-pressure hose - to
outlet point
In the case of a pipeline with
fixed outlet points the high-pres-
sure hose with imprinted work-
ing pressure and temperature
should be attached to the nipple
of the high-pressure cock (1) by
the quick coupling (2). Upon at-
tachment turn the handle of the
high-pressure cock (3) to open
position.
Danger of scalding!
Never dismount high-pressure
hoses at water temperatures
above 50°C.
IMPORTANT: Prior to dis-
mounting of the high-pressure
hose or when changing to
another outlet point the high-
pressure cock should be care-
fully closed. Then activate the
trigger of the spray handle to
relieve the high-pressure hose
of pressure.

12
SH TRUCK
Original Instructions
Pipeline, max. length:
Ø12 x 1,5 - max. 50 m
Ø15 x 1,5 - max. 180 m
Ø18 x 1,5 - max. 500 m
When using max. pipe lengths, only use a high-pressure hose of 10
m.
4.1.3 Spray handle - acces-
sories
1. Pull the blue quick-release
grip (A) of the spray handle
backwards.
2. Insert the nipple of the spray
lance (B) into the quick-
release connection and
release it.
3. Pull forward the spray lance
or any other accessory to
ensure correct mounting
before starting the machine.
NOTE!
Clean nipple of
any impurities
each time the spray lance has
been dismounted.
4.1.4 Selection of spray
lance
You may use a double spray
lance as well as a single spray
lance with the machine.The
recommended nozzle size of
the lance is printed on the data
plate of the machine – i.e. 0550.
The max. pressure of the ma-
chine can be reduced by using
nozzles with a wider diameter.
Never use lances with smaller
nozzles (nominal value /
diameter) than stated on the
data plate.
A
B

13
SH TRUCK
Original Instructions
4.1.5 Application of deter-
gents (external)
If you want to apply detergents
or disinfectants these can be
dosed to the water through an
external in jector. In conjunction
with the injector it may be ad-
vantageous to use a wall rack
on which spray lances, 2 pcs.
of 25 l containers as well as 10
m high-pressure hose can be
placed.
Refer to your Nilfisk sales
representative for your optimal
solution.
Below you will find various
types of outlet points with injec-
tors.
Outlet point with detachable
injector
To be attached to the quick cou-
pling of the high-pressure cock.
To be used for dosing of low-
foaming detergents or disinfec-
tants.
Dosage 1-8%.
Outlet point with detachable
foam injector
To be attached to the quick cou-
pling of the high-pressure cock.
To be used in conjunction with
foam lance for application of
high-foaming detergents or
disinfectants.
Dosage 1-5%.
Outlet point with cleaning
trolley and foam injector
To be attached to the quick cou-
pling of the high-pressure cock.
To be used in the same way as
“Outlet point with detachable
foam injector”.
Makes it possible to place 4
spray lances, 2 pcs. of 25 l con-
tainers as well as 20 m high-
pressure hose.

14
SH TRUCK
Original Instructions
ON
3
4
AB
9

4.1.6 Application of deter-
gents (internal)
If you want to apply a detergent,
do as follows:
1. Fill a detergent into a 25 l
container.
2. Turn the machine on, push
the button for addition of
detergents (9) and lay out
detergent.
The concentration of deter-
gent can be adjusted on the
detergent pump.
3. Turn off the addition of
detergent by pushing the
button (9).
NB: The PH value of the
detergent should be between
5.8 – 8.5%. If you want to ap-
ply a detergent
with another PH
value, an external
injector should be
used (see section
4.1.5).
4.2 Operation
4.2.1 Starting up
The shut-off cock on the water
inlet should be open, and the
spray handle on the high-pres-
sure hose should be closed.
1. Turn the main switch (2) to
position - ON -.
2. Push the green “START”
push button (3).
Check on the pressure gauge
(6) that a pressure is being built
up in the system and that the
motor of the SH TRUCK stops
within c 20 seconds with the
green “START” push button (3)
lit. The SH TRUCK is now in
“Stand-by” mode waiting for the
operator to activate the spray
handle.
If a pressure is not being built
up, vent the machine as de-
scribed in sections 3.7 - 3.8
Venting.
I
I
I
I
I
I
I
I
I
I
I
I
I
+
I
I
I
I
I
I
I
I
I
I
I
I
I
+

15
SH TRUCK
Original Instructions
3
4
5
4
3
OK
ESC
+
MITSUBISHI
DCINPUT
(A) (B)
+-
12345678910 111213 14 15

If the motor of the SH TRUCK
does not start or stops unin-
tendedly with the red “STOP”
push button (4) flashing, an
error is present. Read the error
message through the “Inspec-
tion window” and refer to sec-
tion “7 Troubleshooting”.
4.2.2 Operation - automatic
start/stop
Always hold the
spray lance with
both hands!
The SH TRUCK is automatically
started when the trigger (1) of
the spray handle is activated
and will automatically stop and
enter standby mode when the
trigger is released.
When the machine is not in
use, the trigger should be
locked with locking device.
4.2.3 Running with hot water The SH TRUCK is equipped
with a diesel unit to heat the
water.
The diesel unit can be switched
on or off at convenience by
pushing the white “Heating”
push button (5). Pushing the
button once will turn on the light
in the button and switch ON the
diesel unit.
Pushing the button again will
turn out the light in the button
and switch OFF the diesel unit.
The temperature can be
adjusted within the limits stated
on the “Thermostat” (8), by
turning the button to the desired
value. When the diesel unit is
ON (push button (5) alight), the
control unit of the SH TRUCK
will monitor the water tempera-
ture and regulate the diesel unit
to provide the preset tempera-
ture.
If an error occurs to the heat-
ing system of the SH TRUCK,
the machine stops and the red
“STOP” push button (4) will
start flashing and the diesel unit
will be shut off. The SH TRUCK
will continue to be functional
with non heated water by push-
ing the green “START” push
button (3).
In this case please refer to sec-
tion “7 Troubleshooting”.
1

16
SH TRUCK
Original Instructions
min. max.
OFF
4
4.2.4 Double spray lance,
ressure regulation
The spray lance features 2
nozzles, a high-pressure nozzle
and a low pressure nozzle.
High-pressure mode
When the pressure reducing
valve (1) is completely closed
(turned clockwise - B), only the
high-pressure nozzle is used -
high-pressure mode.
Low pressure mode
When the reducing valve (1)
is completely opened (turned
counterclockwise - A), both
spray lances are used - low
pressure mode / possibility of
dosing detergents.
The pressure can be regulated
between these positions.
4.2.5 Stop Danger of scalding!
Never detach high-pressure
hoses at a water temperature
above 50°C.
Never detach the high-pressure
hose while the machine is in
operation.
1. To stop the machine, push
the red “STOP” button (4).
The red light will come
on. To disconnect the SH
TRUCK completely from
mains, turn the main switch
(2) to position - OFF -.
2. Close the shut-off cock of
the water inlet and activate
the spray lance or open the
high-pressure cock to relieve
the pipeline / high-pressure
hose of pressure.
1

17
SH TRUCK
Original Instructions
-AX#
-IN#
4.2.6 Automatic “system
shut-down”
Your SH TRUCK features a
function called “system shut-
down” that can be enabled by
your Nilfisk service technician
during installation or at a later
time.
When enabled, “system shut-
down” will automatically switch
OFF the SH TRUCK when it
has not been used for a prede-
fined time (from 1 sec. up to 9
hours) at your choice.
Shut-down is disabled on deliv-
ery - please contact your Nilfisk
service representative if you
would like the function(s) to be
enabled.
4.2.7 Frost protection, inter-
nal
heater automatically starting up
when the temperature inside
the machine gets too low.
The adjustment of the thermal
sensor is effected in the electric
box. On delivery the adjustment
has been set at 5°C. This set-
ting must not be lowered.
NB: The frost protection does
NOT function if the machine
has been turned off on the
main switch.
IMPORTANT: For safety rea-
sons, hoses, spray lances
and other accessories should
always be thawed prior to use.
The machine has been con-
structed for outdoor placement.
The machine features a fan
4.2.8 Frost protection, exter-
nal (Option, not stand-
ard)
This option ensures that hose,
handle and spray lance does
not freeze. After use the spray
lance must be placed in the
spray lance holder (pos. 15).
Then turn off the machine on
the front panel.
If the temperature is below the
temperature set on the thermal
sensor in the electric box, the
frost protection will start. Water
will now circulate through hose,
handle, spray lance and back to
the machine.
IMPORTANT: The
frost protection is
not active, when
the machine has
been switched on (ready for
operation).

18
SH TRUCK
Original Instructions
5 Fields of Application and Working
Methods
5.1 Fields of application The most important fields of application for this product are:
Transport Cleaning of trucks, buses, cars etc.
Building & Cleaning of vehicles, equipment, buildings etc.
Construction
Light industry Degreasing and cleaning of machines, workpieces, and
vehicles.
Service Cleaning of vehicles, public baths, institutions etc.
5.2 Working pressure The high-pressure system may be used with high or low pressure
at your own option:
Low pressure Is first and foremost used for the application of detergents
and for flushing.
High-pressure Is used during the actual cleaning.
Intermediate As an example it may be used for the cleaning of surfaces
pressure which cannnot stand a too powerful jet, i.e. soft surfaces.
5.3 Temperature Hot water significantly
increases the efficiency of the
cleaning process – especially
grease, oils and fats can be
broken down more easily at
higher temperatures.
Temperatures up to 60°C
should clean off proteins, such
as blood substances.
Oil and traffic film should be
exposed to app. 70°C, whereas
grease and fat is easiest to
remove with temperatures of 80
to 85°C.
Several detergents become
more efficient when acting with
hot water – please refer to
manufacturers recommenda-
tions.
5.4 Mechanical impact In order to break down tough
layers of dirt, additional me-
chanical impact may be
required. Special lances with
special nozzles (pulsating jet /
concentrated “0” jet) are avail-
able for such purposes as are
rotating brushes plus soft &
sand blasting equipment.
Please ask your Nilfisk repre-
sentative.

19
SH TRUCK
Original Instructions
5.5 Detergents As standard the system is
delivered without a detergent
injector and the optional, factory
mounted, internal chemical
system.
If you want to use detergents
or disinfectants these should
be dosed through an external
injector (see section 4.1.5) or
through the pump (see section
4.1.6).
The most efficient cleaning
is reached with detergents in
conjunction with the high-pres-
sure cleaning. For that purpose
Nilfisk can offer you a series of
products specially developed for
high-pressure cleaning, among
other fields within:
• Cleaning of vehicles,
machines, stalls etc.
• Disinfection
• Degreasing of workpieces
• Descaling
The products are water-based,
without phosphates, and the
applied tensides (surface active
substances) comply with the
present requirements for easy
biodegradability.
Contact your Nilfisk distribu-
tor for directions as to which
product(s) will fulfill your re-
quirements.
The method of application and
the dosage of the individual
products appear from the prod-
uct labels or the data sheet.
Low-foaming detergents are
applied through an injector and
under low pressure. A change
to cleaning under high-pressure
is effected by regulating from
»low pressure mode« to »high-
pressure mode« on the double
spray lance or by attaching a
high-pressure spray lance.
For foam cleaning you will have
to attach a special foam equip-
ment. Insert the suction hose
of the injector into the foam
detergent.
Attach the foam lance on the
spray handle and now you are
ready for foam application.
Upon the application open the
by-pass cock of the foam injec-
tor and replace the foam lance
by a spray lance, and you are
ready for cleaning.
General rules for addition of
detergents
Nilfisk cleaning equipment can
be used for all detergents and
disinfectants, which are suit-
able for high-pressure cleaning
according to the prescriptions
of the supplier. (If using external
injector, section 4.1.5, the pH-
value should be between 4 and
14. If using addition of chemi-
cals through the high-pressure
pump, section 4.1.6, the pH-val-
ue MUST be between 5.5 and
8.5). Acid and lye should not be
applied in a concentrated form.
Carefully observe the prescrip-
tions and guidelines of the
supplier, also the rules concern-
ing safety clothing and drainage
facilities.
Detergents, which are not
exactly prescribed for use in
conjunction with high-pressure
cleaning, must only be used
upon a previous approbation
from Nilfisk and the supplier.
The use of Nilfisk detergents
ensures that machines, acces-
sories and detergents match,
which is the condition of an opti-
mal solution of a cleaning task.
Nilfisk can offer you a wide
range of efficient agents for
cleaning and disinfection. The
products are composed of
substances, which combine
efficiency and environmental
considerations at one and the
same time.

20
SH TRUCK
Original Instructions
5.6 Working methods Your high-pressure hot water
washer has been developed for
cleaning according to the so-
called »2-step method«.
However, your high-pressure
hot water washer must be
equipped with an external
detergent injector.
STEP 1
Application of detergent - soak-
ing.
STEP 2
High-pressure cleaning.
In practice the working process
is laid down in accordance with
the actual job, but as a start-
ing point the following working
method can be described for a
job:
1. Apply detergent under low
pressure. The dosage is
chosen according to the
job, which is to be carried
through, and the adjustment
is made on the dosing unit.
2. Await acting time. Let the
detergent act on the dirt/sur-
face for a short time prior to
pressure cleaning - usually a
few minutes.
3. High-pressure cleaning.
Clean all surfaces under
high-pressure.
4. Rinse afterwards, if neces-
sary. To make sure that resi-
dual impurities are removed
from the surface.
In connection with the working
process the optimum cleaning
will be reached by following
these 3 pieces of advice:
Advice no. 1
When using a detergent, usu-
ally always apply it on a dry sur-
face. If the surface is rinsed with
water at first, it may be difficult
for it to absorb the detergent,
and the result is a reduced ef-
fect of the detergent.
Advice no. 2
When applying a detergent
on large vertical surfaces (i.e.
the sides of a truck) work from
below and upwards. Thus you
will avoid the detergent running
off the surface through grooves
and dark streaks appearing on
the surface whilst cleaning.
Advice no. 3
During the high-pressure clean-
ing you should work so that the
high-pressure water does not
run over the surface which has
not been cleaned yet. This is to
ensure that there is sufficient
detergent on the surface when
the high-pressure water hits the
surface.