Installation, Operation and Maintenance Manual
IO-70103 RevE 08-17
9
Grounding conductors must be routed with the associated power conductors in the same raceway
(conduit). When metallic raceways are used, adequate electrical continuity must be maintained at all
raceway connections, particularly raceway terminations to the electrical enclosures. The use of isolating
bushings or other means to interrupt a metallic conduit run is a potential safety hazard and is not
recommended.
Grounding Electrode:
Surge protective devices do not discharge all surges to ground (earth). Surge
protective devices can also divert the surge current back to its source to complete the electrical circuit.
In the case of lightning whose potential is developed with respect to the earth, the SPD diverts the
surge current to the grounding electrode (earth connection). However, for most transient surges that
are developed by switching loads, the SPD diverts the surge current back to its source without involving
the grounding electrode.
For proper SPD performance, the service entrance grounding electrode system must comply with the
NEC by having all available electrodes (building steel, metal water pipe, driven rods, concrete encased
electrodes, etc.) properly bonded together and connected to the power system grounding.
The use of a separate grounding electrode to ground the SPD defeats the effectiveness of the SPD, is a
potential safety hazard, may cause equipment damage, is an NEC violation (reference NEC 250-51 and
250-54), and is not recommended.
Neutral Connection: NOTICE
- FOR PROPER AND SAFE OPERATION, THE SPDs NEUTRAL MUST
BE RELIABLY CONNECTED TO THE NEUTRAL OF THE SOURCE. FAILURE TO PROVIDE A RELIABLE
NEUTRAL CONNECTION MAY RESULT IN FAILURE!
Parallel Connection / Wire Diagram
