7
WS-200A-4 Operation
The following instructions apply to the WS-200A-4 Water Still
where the water feed to the boiler is via the mains supply or a
header tank.
1. Before switching on either the mains electricity or water supply,
identify the control switches and indicator lights on the front of
the cabinet.
Green Light – When illuminated this shows that there is mains
supply voltage to the unit. Under no circumstances should the
cabinet end-panel be removed when this light is illuminated.
White ‘On/Off’ Switch – This is the primary switch for
controlling water and electricity inside the still. The switch
illuminates when pressed in the ON position.
Amber Light – When illuminated, this indicates that the
distillate collection reservoir is full as detected by the level
control.
White ‘Clean’ Light – This shuts off the heating element
but allows water to flow into the boiler when the still is being
commissioned or cleaned. When pressed in the CLEAN position
the switch illuminates.
2. Carefully check the following:
The appropriate electricity, water and drain services have been
provided. If in doubt, consult the LOCATION & SERVICES
SECTION of this manual.
The ON/OFF switch on the control panel is in the OFF position.
The CLEAN switch is pressed in the CLEAN position.
The stopcock on the boiler level control is closed.
The reservoir water level sensor is fitted to the distillate
collection vessel.
The dummy shorting plug is fitted to the boiler level control DIN
socket on the cabinet.
3. Ensure all earth leads are connected to the earth point.
4. Check all glassware for any damage.
5. Switch on the electricity supply – the green light illuminates.
6. Press the ON/OFF switch to the ON position – the switch will
illuminate.
7. Recheck that the CLEAN switch is in the CLEAN position and
illuminated.
8. Turn on the mains water supply and using the mini valve
assembly, adjust the flow rate to approximately 1 litre/min. This
can be achieved by observing the drain water from the boiler
level control and adjusting the mini valve assembly accordingly.
9. Check for water leaks.
10. Observe the boiler now filling with water to cover the heating
element. When water has reached the pre-set limit, the excess
will discharge to drain. Check the water drains freely and does
not back up into the boiler level control.
11. Switch the CLEAN button off by pressing it a second time. The
switch light goes out.
12. The heater will now warm up and eventually run at a red glow.
If the flow rate is insufficient, the heater will not switch on. This
will require adjustment of the mini valve assembly to be opened
further. After about 2 – 3 minutes of operation distilled water
will emerge from the outlet pipe falling into the collection
reservoir.
13. To avoid excess wastage of coolant water, make further
adjustments to the mini valve assembly. Slowly reduce the flow
rate until the flow control switch switches off the heater, then
increase the flow until the power is restored.
14. Refit the Perspex screen.
15. Safety Cut-Outs – All Cole-Parmer Water Stills are protected
by the following safety devices.
Flow Control Switch – Monitors the flow of coolant water
into the still and shuts off the heating element if the flow is
insufficient.
Thermostat Cut-Out – In normal operation the water within
the glass will be at 100°C. In single fault conditions, i.e. in
the event of water supply failure, the content will increase
to 112°C where upon a resettable thermostat will operate.
Once switched, the thermostat has to be manually reset. This
is achieved by unscrewing the black knob located inside the
cabinet and pressing the reset button.
Reservoir Control – Is positioned in the collection reservoir
and switches off both the electricity and water supplies when
the reservoir is full of distillate water. The water supply is shut
off after around 7 minutes after the reservoir is full to allow the
heating element to cool.
It is recommended that the operation of the flow switch and
reservoir control is checked on a regular basis.
a. Simulation of Mains Water Supply Failure
Turn off the mains water supply at the tap. This should switch
off the heating element. Turning the tap on again will switch
the heater on.
b. Simulation of Reservoir Full Condition
Lower the glass pressure bell of the reservoir water level sensor
into the distillate to a depth of 150mm. This will switch off the
heating element immediately and the cooling water after 7
minutes. Raising the bell will cause both to be switched back
on.
16. Switching Off – Push the CLEAN switch to the ON position.
Wait until the residual heat contained in the heating element
has dispersed and no boiling is evident. Turn off water supply.
Push ON/OFF switch to OFF position. Isolate from mains
electricity supply.
