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4.5.
Personal protective equipment for servicing work
Servicing work on the machine includes all work for which the machine is opened and one or more cover
panels are dismantled. In particular, this includes cleaning work in accordance with
Chapter 8.7.1
Thermostatic
pump start
To save energy, the consumer pump is not operated permanently, but cyclically. An evaporator pump, if
present, is also controlled. The tank heater or compressor is released after a short circulation of the cold
water.
The thermostatic pump start is intended for two applications:
When the chiller is switched on, a defined "start" temperature of the cold water should be made
available to the application. The water temperature is kept at a constant level to prevent
unnecessary temperature drops or increases.
= Pre-tempering
If the system is not installed without anti-freeze mixture in the cold water circuit, a minimum
temperature of 5°C should be maintained.
= Anti-freeze mixture
The tank heater is activated when the temperature falls below the minimum setpoint and the compressor is
activated when the maximum setpoint is exceeded. A separate hysteresis is assigned to each setpoint.
This results in the following control sequence:
Cyclic activation of the pump every 60 min. for at least 5 min.
1 min. after activating the pump (circulation process), the tank heater or compressor is released.
The pump switches off when the runtime has elapsed and the tank heater and compressor are no
longer required by the temperature.
If the interval time is 0 min, the thermostatic pump start is only activated by the temperature. However, the
runtime is effective.
4.5.1.
Electronic level monitoring
Before switching on the chiller the electronic level monitoring starts up.
The level is monitored for three states:
Tank min level STOP; the chiller switches off immediately.
Tank min level warning; the chiller continues running but does not switch back on in the event of a
stoppage. The water feed solenoid valve (only with optional automatic water top-up) is opened.
Tank max level message; the cold water feed, water feed solenoid valve (only with optional automatic
water feed) is closed.
The ideal state is if the level is above the warning level and below the maximum level. In this case no message
appears.
If the chiller is switched on and the min level warning is reached the chiller remains switched on so that any
cooling process that has been started is not interrupted. If the chiller is switched off, the chiller does not start,
to ensure that no cooling process is initiated that may not be able to be ended.
4.5.2.
Switching the chiller On/off
The following conditions must be fulfilled for the chiller Standby state:
The control has completed its initialization routine,
Release of at least one primary pump,
