ABB REL670 - Making the Screen Connection

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Making the electrical connection Chapter 5
Installing the IED
The cubicle must be properly connected to the station earthing system. Use a conductor with a
core cross section area of at least 4 mm
2
(AWG 12).
Figure 18: Rear view of IED with one TRM showing earthing points.
4.5 Making the screen connection
When using screened cables always make sure screens are earthed and connected according to
applicable engineering methods. This may include checking for appropriate earthing points near
the IED, for instance, in the cubicle and/or near the source of measuring. Ensure that earth con-
nections are made with short (max. 10 cm) conductors of an adequate cross section, at least 6
mm
2
(AWG10) for single screen connections.
where:
1 is main protective earth to chassis
2 is earthing screw to Power Supply Module
3 is earthing screw to TRM. (There is one earth connection per TRM)
2
1
3
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