Douwe Egberts CAFITESSE 014, Руководство по обслуживанию

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January 2001
5A - 30
Functions - Water System Service Manual Cafitesse 500
●
The watchdog relay on the control circuit
board interrupts the safety circuit if it
detects a dangerous condition.
●
The boil over sensor and the dry running
protection operate independently of the
electronic control and protect the hot water
system if the elctronic control fails.
●
An error message is displayed when the
safety circuit is interrupted.
Software protection
against overheating and boiling over
●
Following functions of the electronic control
protect the hot water system against
overheating and boiling over:
1. Temperature regulator function:
The boiler temperature is greater than
the programmed temperature.
When the boiler temperature exceeds
the required (programmed) temperature
the heating is switched off via the relays.
2. Interruption of the safety circuit when:
the boiler temperature is greater than
the programmed temperature + 9 °F
(ERR 3)
The watchdog relay opens when the
sensor detects an unacceptable high
boiler temperature (more than 9 °F
above the programmed temperature).
This function is to prevent that during a
failure of the relay the safety circuit only
switches off when the boil over sensor is
activated due to excessive development
of steam. (Temperature is greater than
185 °F, ERR 4)
3. Interruption of the safety circuit when the
electronic control fails
The watchdog relay is automatically
opened when a malfunction in the
running of the program (microprocessor)
occurs.
Software function:
Software protection against overflow of the
boiler
●
The safety circuit is switched off by the
watchdog relay when the water supply
system cannot refill the boiler within
30 sec. Among other things the inlet valve
is switched off (The display shows an error
message).
●
The time starts running when the float has
detected a low level.
●
Only when the dispenser is started by a
Power ON-reset (take out the mains cable
and put it in again) a longer time is valid
for the first filling: 120 sec. otherwise the
display shows an error message.
●
If a malfunction occurs the watchdog
relay switches off
-
The heating is switched off
- The cooling system and the fan remain
switched on.
CAUTION: After a repair of the circuit
board its function has to be
checked.
The float serves as a dry running protection
●
The relay switches the heating off when the
float and optical sensor detect a water level
that is too low for more than 30 sec.
●
If this system does not work the capillary
tube temperature limiter will act as a dry
running protection.