Operating manual ef cooling Ernst H. Furrer AG
Cooling unit EVO 45, 0390.013 Issue: 07 / 2015 Chapter-Page 2-11
Float switch with low and high switch point
The low switch point monitors the water fill level in the tank. Thus temperature constancy in the
water outlet, and the dry run protection of the pump are achieved. If there is a malfunction, the
controller switches off the pump and also the cooling and signals the malfunction on the display.
The cooling is switched back on after water is topped up and the alarm on the display has been
acknowledged.
(See also Chap. 7.1.3 Troubleshooting at operator level and 9.4 Troubleshooting at repair
level).
Float switch high
The high switch point outputs a warning on the PLC display. Top up water to "Max." marking.
2.12.4 Monitoring devices
Motor protection switches – compressor, pump, fans
If there is increased motor power and if there is a short circuit, the motor protection switch
switches off and interrupts the power supply. The fault is shown on the display. The cooling is
switched back on after the fault has been cleared and the alarm on the display has been
acknowledged.
(See also Chap. 7.1.3 Troubleshooting at operator level and 9.4 Troubleshooting at repair
level).
Microprocessor-controlled programmable logic controller (PLC)
The PLC regulates the temperature and monitors the excess temperature or insufficient
temperature. If the water temperature is too high or too low, the controller switches the laser
enable off and shows the malfunction on the display. The laser is enabled after the water is
back in the operating range and the alarm on the display has been acknowledged.
(See also Chap. 13-57 PLC manual, 7.1.3 Troubleshooting at operator level and 9.4
Troubleshooting at repair level).
Monitoring the air filters
The high-pressure transmitter monitors the system pressure on the high-pressure side. If the
condensation pressure is outside of the normal work range but within the limit value, the display
shows a warning.
(See also Chap. 13-57 PLC manual, 7.1.3 Troubleshooting at operator level and 9.4
Troubleshooting at repair level).
2.12.5 Temperature regulator devices
Microprocessor-controlled programmable logic controller (PLC)
Temperature control and regulation of the water circuit are handled by the PLC. The PLC
regulates the water temperature depending on the set setpoint. The tank temperature is shown
on the display.
(See also Chap. 13-57 PLC manual, 7.1.3 Troubleshooting at operator level and 9.4
Troubleshooting at repair level).
2.13 Use of original spare and wear parts
Only original spare parts may be used. Proper functioning of the cooling unit can no longer be
guaranteed by the manufacturer if third party spare parts are used. In such cases, all warranty
claims are automatically void.
2.14 Safety concept
This cooling unit is part of a wider system and must consequently be integrated in the safety
concept of the wider system.
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