Woodward AtlasPC, Руководство по оборудованию

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Manual 85586V1 AtlasPC Digital Control, Vol. I
Woodward 9
Figure 2-2. Fixed Terminals
Grounding
Protective Earth (PE) must be connected to the termination point on the backside
of the unit next to the label with the symbol to reduce the risk of electric
shock. This connection will be made using a thread-forming screw (M4 x 6 mm).
The conductor providing the connection shall have a properly sized ring lug and
wire larger than or equal to 3.3 mm² (12 AWG).
Recommended Grounding Practices
Providing the proper ground for the AtlasPC control is important. Improper
connection of the control chassis to the ground plane may lead to stray currents
between the reference point for the ac signal sources (current and voltage
transformers), and the reference point for the sensing inputs on the AtlasPC
control. Differences in potential between these two points results in equalizing
current flow which then produces unacceptably high common mode voltages.
Common mode voltages may result in improper readings for the sensed ac
inputs, or even damage to the AtlasPC control in extreme cases. To minimize
this problem, it is necessary to provide a low resistance path between the ac
signal reference point, and the chassis of the AtlasPC control. Typically this point
is the designated ground for the generator set and related instrument
transformers.