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1. GENERAL
The ULTRAFREEZER series Ultra Low Temperature freezers have a storage freezing system with
a temperature range from -50°C up to -86 °C.
Cooling is realized by means of a cascade system, where in the highest stage (first) R507 is used
as refrigerant and in the lowest stage (second) a mix of R508b and R170. Both the high as the
low stage are fitted with a capillary injection.
The cooling system is protected by a pressostat, a thermostat, a time delay for the second stage
and a clixon thermal protection.
The ULTRAFREEZER is controlled by a microprocessor controller. When cooling is necessary, the
cooling-relays and fan are activated. After a cooling action, the fan still runs by means of a time-
delay. Temperature measurement will be done by a 2 wire PT1000 sensor.
The controller has a connection for an external backup battery. The battery will be loaded
continuously by the controller, so it will always be stand-by. During power-failure of the main
voltage, the controller still remains in function. With the standard battery the controller will still
function for a few hours. The current-loader of the controller can also be used for loading a
battery of the optional CO
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backup cooling-system.
The controller has an alarm-system, which will be activated when the set minimum or
maximum alarm temperature will be exceeded or when a sensor is defective.
Through the built-in buzzer, the alarm leds and errors on the front and the potential free alarm
contact will activate. In case of exceeding the maximum CO
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-alarm temperature, the CO
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backup cooling will switch on. This is a pulsating contact. The contact remains active until the
set temperature has been achieved. When the temperature has been restored, the relevant
error remains in the display, to remember the error. In case a power failure occurs and any
emergency power is present, the CO
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relay keeps on switching continuously.
An acoustic and visual alarm will be activated if the door is open more than 30 seconds (the
door delay is adjustable): code alarm E6.
The controller has an internal memory of 512 MB to store the measured temperatures, set
setpoints etc. The sample frequency is done every 5 minutes and the memory is stored for up
to 6 months. Also during power failure (thanks to an external back-up battery), the values will
still be stored. Ultrafreezer has both an Ethernet and USB connection.
To prevent impermissible use, such as ON/OFF switching or changing parameters/ setpoints,
the controller can be protected by using a password which has been entered through the Code
button.
The control settings of the panel can be adjusted via the internal parameters.
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