Betriebsanleitung_HF3_14_de - 第599页
12 2KE0041502 - englisch_BA 04.1 1.2010 ENGLISH 2.4 Safety Devices The process cooler is equipped with the following safety devices: High-pressure control (HP) The high-pressure control is designed to protect the process…
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2KE0041502 - englisch_BA
04.11.2010
ENGLISH
2.2 Water Circuit
(See also flow diagram of pipes and instruments)
2.2.1 Single Circuit System with Tank
The water circuit with its integrated tank is designed as a system open to the atmosphere. The
constancy of the water outlet temperature is governed by the water volume inside the tank. The
pump conveys the water out of the tank to the equipment to be cooled and back to the tank via
the evaporator.
2.3 Cooling Air Supply
The heat transferred to the evaporator upon cooling the water as well as the heat of the
compressor motors are absorbed by the refrigerant and given off to the cooling air in the
condenser.
As cooling air the ambient air is used which is drawn through the condenser by the fan(s),
warmed and then discharged in upward direction
It must be ensured that the cooling air can be drawn in and discharged without any
obstructions and adequate air changes for heat dissipation away from the installation
site of the process cooler take place.
(see also Section Installation)
2. Description of the Process Cooler
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2KE0041502 - englisch_BA
04.11.2010
ENGLISH
2.4 Safety Devices
The process cooler is equipped with the following safety devices:
High-pressure control (HP)
The high-pressure control is designed to protect the process cooler against extremely high
operating pressure in the refrigeration cycle.
In the event of a malfunction, the HP control switches the process cooler off, and the
malfunction is indicated on the control panel.
The process cooler cannot be restarted until the pressure has dropped to the preset pressure
difference and the Reset button on the pressostat has been pressed.
The high-pressure pressostat can be accessed from the service side.
2.5 Monitoring Devices
Low-pressure control (LP)
The low-pressure control protects the process cooler against extremely low operating pressure
in the refrigeration cycle.
In the event of a malfunction, the control switches off the process cooler, and the malfunction
is indicated on the control panel.
Restarting of the process cooler is effected automatically as soon as the pressure has risen
by the preset pressure difference.
Winter starting aid
The winter starting aid is designed to prevent any low pressure malfunctions in low ambient
temperatures during the start-up phase of the cooling operation until normal operating
conditions have been established.
Compressor overheat protection
The compressor is equipped with an overheat protection (thermal contact, Klixon). In the event
of an increase in motor current in conjunction with a rise in winding temperature, the overheat
protection trips, and the compressor is switched off. The overheat protection resets itself
automatically after the windings have cooled down. The malfunction is indicated on the control
panel.
Thermal contact – fan motor
In the event of an increase in motor current in conjunction with an increase in winding
temperature, cooling operation is switched off by the thermal contact.
This malfunction is indicated on the control panel.
Circuit breakers (compressor, fan, pump)
In the event of an increase in motor current or in the case of short circuits, the circuit breaker
trips and interrupts the power supply.
Such malfunctions are indicated on the control panel.
The circuit breakers are located in the control cabinet.
2. Description of the Process Cooler
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2KE0041502 - englisch_BA
04.11.2010
ENGLISH
Float switch
The float switch monitors the water level in the tank.
A signal lamp in the control cabinet door indicates lack of water when the water level falls
below the minimum level. The cooling operation remains activated.
If the water level continues to fall and once the minimum limit value is reached, cooling
operation and pump(s) will be switched off.
Restarting the process cooler is not possible until the water has been replenished up to the
MAX mark at the filling level indicator.
The float switch is located in the tank.
Fan control
The condensation pressure is controlled by cycling the individual fans on and off.
This type of control permits an adaptation to different operating conditions at relatively constant
condensation temperatures.
Control and Operating Unit
The control and operating unit controls the water circuits and the refrigeration circuit.
The control panel with display of the water temperatures, as well as the error codes in the case
of a general fault alarm, is integrated in the control cabinet door.
2.6 Electrical / Control Equipment
The electro-technical equipment of the process cooler is installed in the control cabinet. All
required components for the automatic switching, controlling and regulating operation are
contained in the control cabinet.
The main electric circuits are of a non-fused design featuring motor protecting switches.
The connection of the process cooler to the equipment to be cooled is effected via a potential-
free interface.
The interface transmits the following signals:
- „ Malfunction ’’ Continuous signal from the process cooler to the equipment to be cooled.
The water outlet temperature is kept constant by the control and operating unit at a given
setpoint value by activation of power stages in the refrigeration cycle. The current water outlet
temperature is displayed on the control panel.
2. Description of the Process Cooler