3.
ELECTRICAL SYSTEM DESIGN
3.1
4/20mA loop
The BA627E-SS requires an operating voltage
between 6.1 and 30V. Design of the loop is similar
to that for a 2-wire temperature or pressure transmit-
ter.
Fig 2 illustrates a typical application in which a
BA627E-SS is powered from a common supply.
When designing the loop it is only necessary to es-
tablish that the maximum voltage drop caused by the
Set Point Station, the load and cable resistance is al-
ways less than the minimum supply voltage.
For example:
Minimum operating voltage of BA627E-SS 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-SS.
Fig 2 Typical application
4.
INSTALLATION
4.1
Location
The BA627E-SS Set Point Station has a stainless
steel case with a 10mm thick toughened glass win-
dow. The case provides 7J and the window 4J front
of panel impact protection. The captive silicone gas-
ket, which seals the joint between the instrument and
the panel enclosure, ensures IP66 front of panel in-
gress protection.
The rear of the instrument has
IP20 protection.
Although the front of the instrument has IP66 protec-
tion, it should be shielded from continuous direct
sunlight and severe weather conditions.
The BA627E-SS Set Point Station may be installed
in any panel enclosure providing that the operating
temperature is between -40°C and +70°C.
Fig
3
shows
the
overall
dimensions
of
the
BA627E-SS together with the recommended panel
cut-out dimensions and terminal identifications. To
achieve an IP66 seal between the instrument enclos-
ure and the instrument panel an aperture with the re-
commended tolerance should be used.
Fig 3 Dimensions
6
Summary of Contents for BA627E-SS
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