Fire safety is one of the highest priorities and motivations for deploying an integrated services bonding point (ISBP). To this end, bonding and grounding within the ISBP suite should be in accordance with the Proxy Earth Protocol (PEP).
The fact of integrated systems bonding means that you can expect lightning current to pass across the ISBP suite. The more fill of conductors in the modules, the less oxygen is available to fuel any combustion or to oxidize the wires. There is more surface area to conduct current, meaning that the ISBP will pass current faster (more current at the same time means less total time) and the ISBP and grounding electrode conductor (GEC) will be more responsive to the passing of high current, even lightning.
The more bonding points used, the less opportunity for arcing and sparking. A well wired, extensively bonded ISBP should be able to survive the heat and current of multiple lightning strikes.
ISBP module bonding should first include the GEC. The GEC should bond to each module by passing through centered bus bars. If the modules are constructed as an in-line unit, then it will be easy to pass the GEC right on through the middle. Try to pass the GEC straight through the middle of the in-line modules without any large-angle bends (90+ degrees). GEC should be in the center hole position of any bus bars. Having two bus bars per module, each parallel and passing the GEC through, would be ideal because enough bonding points would be available for the bonding superhighway as well as for future expansion needs of individual system modules.
Fasteners for adjacent modules also will function as bonding devices, but this is not to be relied upon. Instead, run a system of bonding jumpers between modules, observing the long and short wavelengths within the ISBP suite. If there are positions remaining available on the bus bars after integrating all systems, then fill those across all modules as a parallel “bonding superhighway” to the GEC. This will reduce resistance within the ISBP and function as a drain for current.
Line up bonding jumpers to pass current across the length and width of modules, and to parallel the GEC. The largest practical bonding jumper or ground wire size should be used once you identify the two specific points for bonding. However, no jumper should be smaller than American Wire Gauge (AWG) 14, while AWG 12 is preferred as the minimum size. Bonding jumpers should not block visual or manual access to the inside of an ISBP module.
There is no such thing as a “ground loop” where the ISBP is concerned. If redundant bonding and grounding is done in connection with an ISBP, then all is balanced and you have a low-resistance ground with high ampacity.
The ISBP suite must be accessible, but enclosed. The enclosures will protect and extend the life of all bonds within the ISBP suite. Enclosures could be as simple as a 4 X 4 steel box, but must be conductive in order to give electrical shielding. The enclosures and cover will also complement the ampacity and heat-transfer capability of the ISBP suite. Bonding the cover and or enclosure with a jumper to the ISBP module would be very prudent.
Keep ISBP module covers clear for easy access. If you bond the cover inside, then leave the bonding jumper long enough for opening the cover and working inside the module.
Summary
There are many tangible benefits obtained from the ISBP suite and from extensive use of bonding jumpers within each module and between modules.
The bonding of ISBPs together is a necessary force multiplier that decreases resistance and increases ampacity and responsiveness of the ISBP system. Survivability is enhanced.
