Appendix 2 Grounding & Lightning Protection
The grounding and lightning protection of low voltage power supply
system is a systematic engineering, of which the grounding and
lightning protection of UPS is only a part. According to relevant
international, domestic and industry standards,
lightning protection
measures should be taken at the primary and secondary sides of the AC
power transformer
before the power line is introduced into the UPS
machine room
, and there are stringent requirements on the length and
grounding mode of the low voltage power cable introduced into the UPS
machine room, on the lightning protection, shielding, and lightning
protection ground cable of the UPS machine room.
To ensure human safety, the UPS must be reliably grounded prior to
use, i.e., the UPS protective ground (the metal case of the UPS)
must be reliably connected to the ground bar in the machine room
by connecting the input ground line terminal on the UPS terminal
block to the machine room ground bar. In addition, the mains
frequency ground resistance of the machine room ground bar
should be in compliance with relevant standards, normally less than
5 ohms. To ensure that the ground cable inside the UPS is reliably
and safely connected, the iTrust UPS had undergone stringent
internal ground resistance test at factory before despatch.
The iTrust UPS provides perfect lightning protection. All lightning
protection elements are made by world known manufacturer or
military standard products, and the SPD (surge protection device) is
designed and installed in strict accordance with the IEC standard.
After other lightning protection actions of low voltage power supply
system stated above are taken in compliance with requirements, the
harm that the lightning strike may do to the UPS machine room is
minimized.
Appendix 2 Grounding & Lightning Protection 51
E1-20010916-C-1.0
