Dynalab 3999-0000 - Manuel (Page 6)

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CARE AND MAINTENANCE
N.B. Before commencing any maintenance, cleaning
or fault finding the equipment should be
isolated from the mains electricity supply. These
operations should only be carried out by
suitably qualified personnel.
Only spare parts supplied or approved by Bibby Sterilin Ltd
or its agent should be used. Fitting of non-appr oved parts
may affect the performance or safety of the equipment.
CLEANING
Over a period of operation scale will build up inside the
boiler. To obtain optimum performance this scale should be
removed on a regular basis.
The time span between cleaning depends gr eatly on the
hardness of the water and the amount of use. Fr equently
used stills in hard water areas may need descaling once a
week whereas in a soft water area several weeks may
elapse before descaling is necessary.
N.B. Heavy scaling will reduce distilled water quality
and can shorten the life of the heating element.
It is possible to descale the Distinction W ater Still without
dismantling the glassware by following these instructions in
conjunction with Control of Substances Hazardous to Health
regulations (COSHH) 1988:
1. Switch off the electricity supply to the still and allow it
to cool completely.
2. Turn off the cooling water supply.
3. Open the stopcock on the constant level contr ol and
allow the boiler to drain completely. Close stopcock.
4. Turn on the cooling water supply and allow the boiler
to fill to approximately half way to its normal operating
level. Turn off the water supply.
5. Into the open funnel of the constant level contr ol
carefully add about 100ml of concentrated
hydrochloric acid.
WARNING!
ALWAYS HANDLE STRONG ACIDS WITH GREAT
CARE. PROTECTIVE CLOTHING, GLOVES AND FACE-
MASKS SHOULD BE WORN DURING THE
DESCALING OPERATION.
REMOVE ANY ACID SPILLS IMMEDIATELY.
Turn on the water supply and fill the boiler to the
normal operating level. The water will flush the acid
into the boiler. The water supply should be tur ned off
when the level in the boiler is slightly below the
overflow.
6. Leave the acid in the boiler to dissolve the scale. This
may take some time depending on the severity of the
build-up.
7. Open the stopcock and allow the boiler to drain.
Note: If the acid in the boiler has not been
completely neutralised the liquid flowing to drain
may be highly acidic. All necessary safety
precautions should be observed around the drain
and any effluent control procedures followed.
8. Close the stopcock, turn on the water and allow the
boiler to fill with cold water. Turn off the water, re-
open the stopcock and allow the boiler to drain.
Repeat this procedure three times.
9. The Distinction Water Still may now be restarted by
referring to the instructions given under “Operation”
in this manual.
Note: The stand and outer surfaces of the glasswar e
should be cleaned using a damp cloth and a mild
detergent solution.
HEATER REPLACEMENT
*
1. Isolate the Still from the electricity supply.
2. Clean the heater and boiler if they ar e heavily scaled by
following the cleaning instructions given in this
manual.
3. It will be found easier to r eplace the heater by working
with the boiler “on the bench”.
Therefore:
❖ Drain the boiler via the stopcock.
❖ Remove the end panel.
❖ Disconnect the heater cable.
❖ Disconnect all water hoses.
❖ Remove the condenser.
❖ Remove the boiler, complete with heater, from
the stand.
❖ Unscrew the 3 bolts securing the heater and
withdraw the heater from the boiler.
❖ Remove the aluminium plate and silicone rubber
ring from the heater.
4. Now fit a new heater as described in assembly
instruction number 4.
N.B. Examine the silicone ring and replace if not
in good condition.
5. Re-assemble the Still by following the assembly
instructions.
*
Note: Heater is not covered by the 2 year warranty.
It is only guaranteed for up to 1000 hours in use.