harm that the lightning strike may do to the UPS machine room is
minimized.
Classified by the different throughput capacity and installation place,
usually the UPS system has no more than 2 levels of lightning
protection. The first level lightning protection adopts C-class SPD (
or
-class) with a max throughput capacity of 40kA, waveform 8/20 s,
installed between the UPS and the AC distributor; the second level
lightning protection adopts D-class SPD
(or
-class
) with a max
throughput capacity of 8kA, waveform 8/20 s, installed inside the
UPS. Standard D-class SPD is installed inside the iTrust UPS, and
the SPD24SZ C-class SPD produced by Avansys is recommended.
User may decide whether to select C-class SPD according to the
actual situation of the machine room. Whichever brand C-class SPD
is selected, the connection method shown in the following figure
must be adopted between the C-class SPD and the UPS, i.e., the
protective ground (the UPS metal case) and the C-class lightning
protection ground of the UPS share the same ground, and are then
connected to the ground bar in the machine room.
44 Appendix 2 Grounding & Lightning Protection
E1-20010915-C-1.0
