Douwe Egberts Cafitesse 700, Back Office Manual

Page: 222 / 265

July 2004
5F - 20
Functions - cooling system
Monitoring – Peltier current
• The intensity of the Peltier current is regis-
tered by the control system by means of
voltage via a measuring resistor (0.1 ohm;
on the control system board).
• In order to prevent consequential damage
in the case of an imminent short circuit of
the Peltier element, the cooling system is
switched off:
- if the electric current flows constantly
exceeding 6 A for more than approx. 1
sec. (message error 35, 36)
or
- if the current flows constantly below
approx. 1.7 A for more than 1 sec.
(message error 33, 34).
The cause of this error can lay with the
missing heat dissipation by the heat sink
(the heat sink is completely soiled or the
fan is standing still).
With an increasing heat sink tempera-
ture, the current through the Peltier
element decreases.
• Normally, (i.e. in a stable cooled state), a
Peltier current flows within a range of
2.7–3.1 A. In the first minute following an
interruption of electric current, however, the
electric current can be up to 15% higher.
Cafitesse 700 - Functions - cooling system