ABB AC 800M, Аппаратное обеспечение и эксплуатация

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Section 3 Configuration Powering from an Ex24 V DC Source
3BSE 027 941 R301 105
Connection alternatives
The field equipment power supply can be connected in the same manner as that used
for connecting and powering the AC 800M units (see
Figure 31 on page 106).
However, it should be noted that the same Mains Breaker Unit can be used to
control and isolate both power supplies. Alternatively, independent Mains Breakers
can be used on each spur (see
Figure 32 on page 107).
Powering from an Ex24 V DC Source
The AC 800M Controller can be powered from an ex24 V DC source. This
source is often common for many different types of plant equipment, resulting in
long power cables to the AC 800M Controller. Furthermore, heavy load changes can
cause variations in controller supply voltage making it necessary to take precautions
against low voltage in order to prevent controller malfunction.
Should there be a risk that the +24 V at the PM8xx power terminals could drop
below 19.2 V for more than 1ms, then an energy reservoir must be used for
Powering Units. The recommended solution is to use a DC/DC converter in the
controller cabinet. This converter can also provide isolation between the AC 800M
supply and the external DC source and eliminate grounding problems between the
controller and other parts connected to the same source.