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 ground pin of the UPS input plug 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
Appendix 2 Grounding & Lightning Protection 43
E1-20010915-C-1.0
