Protective Earth, Simultaneous Touch (PESTs) Protection
The Smart PRO’s PEST solution can operate under four of the indents of BS
7671:2018+A1:2020 Amendment 1; section 722.411.4.1, for the purposes
of design/installation we have two modes of operation which INDRA call A & B.
Mode A can be configured with or without a reference electrode.
The safest installation configuration is always mode A with reference electrode
• Mode A with reference electrode – Indent iii – PME (Protective Multiple Earthing)
as CPC with a TT reference electrode and the only method for imbalanced 3 phase
installations (3 phase installations that do not meet the requirements of indent i)
• Mode A without reference electrode – For installations that do not fall under the
requirements of 722.411.4, TT installations, indoor installations, balanced 3 phase
installations (indent i), installations where PME is bonded to Earth in accordance
with indent ii and installations where protection is provided by a third party
device (e.g. matt:e).
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