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HD 4000 C / HD 6000 C
English
5.956-648 A10369 (06/98)
3. Removing the Cover
Certain repair or service procedures may
require the removal of the cover.
Proceed as follows:
n
Remove cover, “A”.
n
Remove both cover retaining screws, “B”.
n
Slide off cover horizontally, as indicated
by the arrow.
4. Decalcification
!
Danger!
Explosion hazard through flammable gases!
Smoking is prohibited when carrying out
decalcification procedures. Ensure
adequate ventilation.
Caution!
Acid hazard!
Protective goggles and gloves must be
worn.
Lime deposits throughout the water lines of
the high-pressure system create increased
pipe-run resistance and may result in the
failure of calcified components.
According to official regulations, only
approved boiler scale dissolvants (de-
scaling acid) with test mark may be used.
For scale removal in the high-pressure
system, the use of KÄRCHER scale
dissolvants should be given preference
(RM 100 ASF, hydrochloric acid-free, part
no. 6.287-008, or RM 101 ASF, containing
hydrochloric acid, part no. 6.287-013).
E. Maintenance
E6
These products are balanced for use in
conjunction with the materials present
throughout the system. After decalcification
we recommend neutralising the remaining
acid residues by flushing the system with an
alkaline solution (pH value 7–8).
The instructions for use and accident
prevention regulations (dilution according to
label specifications), and in particular VBG1,
§ 4, 14, and 44–47 must be observed.
Proceed as follows:
Begin by decalcifying the float reservoir:
Close water supply.
Remove cover as discussed in para. 3,
above. Remove the float reservoir lid.
Remove the hose connecting the pump
suction side with the float reservoir, pump
side. Block the free end of the hose. Pour in
7-percent de-scaling solution. After the
conclusion of decalcification, remove all scale
residues from the reservoir!
Decalcifying high-pressure system:
Disconnect high-pressure hose from water
supply inlet and hang into float reservoir.
Next, use the decalcifying acid solution pre-
mixed in the float reservoir for shortterm
system operation in circulation (idle pressure)
mode. Allow chemicals to activate, and
conclude by flushing the system.
Decalcifying the cooling coil for the pump
motor:
If the flow of cooling water falls below the
prescribed rate (see Technical specifica-
tions), in spite of sufficient input pressure
and a clean strainer in the pressure reducer,
then the cooling coil must be decalcified.
Close the cooling water supply.
Remove, i.e., pull off, the water hose from
the solenoid valve and hang into a catch
container. Remove cooling water hose from
float reservoir, position open end of hose at
suitable height and fill with de-scaling
solution. Allow to activate and conclude by
flushing repeatedly.