Page 213 - Electrical Safety of Low Voltage Systems
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196 Chapter Eleven
FIGURE 11.8
Panelboard with an
“active” door.
to touch a live part of equipment increases, and so does the risk of
indirect contact.
In some cases, though, the panel door may directly open to ex-
posed live parts (i.e., bus bars), that is, the door is part of the enclosure
and prevents direct contact. In this case, the door, even if it lacks live
conductors, must be bonded. 6
11.5 Earthing Conductors and Main Earthing Terminal
Earthing conductors link the earth electrode(s) to the main earthing
bus. The cross-sectional area of these conductors can be selected or
calculated as seen for the protective conductors in Sec. 11.3.
If the earthing conductors are embedded in the soil, they must
endure mechanical stress and corrosion without compromising their
electrical continuity. To this end, their minimum standard cross-
sectional areas can be selected from Table 11.9 as per IEC 60364–5-54.
The main earthing terminal links together protective conduc-
tors, equipotential bonding conductors, and earthing conductors.
