Memmert CDP 115 Peltier cooling unit (Generation 2003) - Manual (Page 15)

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Waterbath cooling unit CDP 115
4. Operation
There must not be any coarse-grained particles in the waterbath. This could damage the
cooling unit.
4.1 Switching on and off
► To start operating, switch on the cooling unit
on the mains switch (Fig. 21).
► Use the mains switch to switch off the cool-
ing unit.
You can see that the unit is on if the fan is
turning. If the fan is not turning, the automatic
switch-off has probably been triggered (see
section 4.3).
4.2 In operation
The refrigeration capacity is constant and cannot be regulated. The cooling unit works at a
constant power as long as it is switched on. The temperature control of the water is taken
over by the waterbath; its controller automatically takes into account the cooling performance
of the cooling unit.
Do not operate the cooling unit when the waterbath heater is switched off. This could trigger
the automatic switch-off (see next section).
If the water in the waterbath is to be heated up to above room temperature, it is recom-
mended that you switch the cooling unit off.
4.3 Automatic switch-off
The cooling unit has a low temperature fuse which switches off the unit automatically when
the water temperature is at about 3 ºC, to prevent icing and possible damage to the cooling
element. When the water temperature reaches about 5 ºC, the cooling unit switches back on
again.
4.4 Function test
► You can see that the unit is on, and that the Peltier element is cooling, if the fan is turning.
► To check that the unit is pumping, pull off the suction tube from the tube suspender and
place a finger on it to test for suction. If there is no suction effect: See next section, Trou-
bleshooting.
Fig. 21 Mains switch