Alpha
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Unit description
4.1
Environmental conditions
The operation of the thermostats is only allowed under the following conditions as specified in
DIN EN 61010-1 and DIN EN 61010-2-010:
Indoor use.
Operation of the device up to an altitude of 2000 m above sea level.
Foundation must be dense, even, non-slippery and non-flammable.
Keep clear distance (
Ambient temperature range (
Use only within this range for an undisturbed operation.
Mains supply voltage fluctuations (
Relative humidity (
10).
Transient over voltage according to Installation Categories (Over voltage Categories) II.
Pollution degree: 2.
4.2
Types of unit
The type designation of the Alpha thermostats consists of the letter A or RA (R for identification as low-temperature
unit = cooling thermostat).
The immersion thermostat Alpha (control head) and the type of bath or the refrigeration system respectively.
Examples:
RA 8 = Immersion thermostat Alpha (control head) and refrigeration system with bath of 8 liters maximum volume.
A 12 = Control unit Alpha with bath of 12 liters maximum volume.
4.3
Baths
All units -except the immersion thermostat- provide a stainless steel bath. The last two digits of the model no. corre-
spond to the approximate total volume in liter (for example bath RA 24 = approximately 24 liters).
Part of this volume may be used to insert objects. Be precautious to overflow when inserting large volume samples!
For the immersion thermostat the bath volume is limited to 25 liters. The bath has to provide a reliable option to fix the
thermostat clamp (wall thickness 10 – 30 mm).
4.4
Pump
All units are equipped with a centrifugal immersion pump. The pumps are driven by a shaded pole motor
.
The pump outflow connection can be closed without causing any damage to the pump.
The pump flow can be reduced by the pump outflow reducer.
Pump characteristics (
10 Technical data).
Содержание Alpha
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