BEKA BA627E, Instruction Manual, Page: 5 / 16

3. ELECTRICAL SYSTEM DESIGN
3.1 4/20mA loop
The BA627E requires an operating voltage between
6.1 and 30V. Design of the loop is similar to that for
a 2-wire temperature or pressure transmitter.
Fig 2 illustrates a typical application in which a
BA627E is powered from a common supply. When
designing the loop it is only necessary to establish
that the maximum voltage drop caused by the Set
Point Station, the load and cable resistance is
always less than the minimum supply voltage.
For example:
Minimum operating voltage of BA627E 6.1V
Maximum voltage drop caused by
speed controller which is a 250ohm
5.0V
load (250ohms x 20mA)
Maximum voltage drop caused by cable 0.2V
resistance (10ohms x 20mA)
---------
Total maximum voltage drop 11.3V
The power supply voltage must therefore be greater
than 11.3V, but less than 30V which is the maximum
operating voltage of the BA627E.
Fig 2 Typical application
4. INSTALLATION
4.1 Location
The BA627E Set Point Station has a robust glass
reinforced Noryl enclosure with a toughened glass
window. The front of the instrument has IP66
protection and a gasket seals the joint between the
Set Point Station enclosure and the panel. The rear
of the instrument has IP20 protection.
Installation may therefore be in any panel providing
that the operating temperature is between –40ºC
and +70ºC.
Fig 3 shows the overall dimensions of the BA627E
together with the recommended panel cut-out
dimensions and terminal identifications. To achieve
an IP66 seal between the instrument enclosure and
the instrument panel an aperture with the
recommended tolerance should be used.
Fig 3 BA627E dimensions
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