R Series
30934 V2
Operating Manual
Page 10
www.grantinstruments.com
5.2
Using the R unit
5.2.1 Product description, refrigeration unit front panel (grille removed)
The over temperature protection reset: protects the unit from overheating by the over
temperature cut-out. This will be actuated when the working fluid is raised above
between 110°C and 120°C. The unit can be reset by waiting for the liquid to cool below
100°C, then unscrewing the black cap and pushing in the revealed button.
The freezing protection switch uses a low temperature thermostat to ensure the working
fluid never drops below 5°C. With the switch in the depressed/in position the cooling will
be switched off by a low temperature protecting thermostat. If water is used in the bath
this will prevent it from freezing. In the out/off position the thermostat is bypassed
allowing the unit to run at temperatures below 5°C.
The drain port and insert allow convenient emptying of the refrigeration bath. To drain
the unit first remove the drain insert from the holder and connect a suitable length of
hosing with a bore of 12.7mm (½’') to the drain insert. Have the non connected end of
tubing in a receptacle, suitable for the liquid to be drained. Push the drain insert into the
drain port and let the liquid drain. To release the drain insert push down the grey button
on the drain body and extract the drain insert. Liquid to be drained should not be below
10°C or above 50°C.
Power switch
Over temperature protection reset
Freezing protection, 5
˚C switch
Drain port
Drain insert
Condenser fins