BS7671 is primarily intended for use in the UK with our standard voltages.
Using BS7671 in the Philippines with USA standard supplies and voltages is never going to be fully compatible. Its a square peg and round hole situation.
I agree- which, IMO- gives me grounds to question Table 41.1 in BS7671 and IEC60364-4-41. IMO both these codes are 230 volts centric, meaning they give little thought when dealing with systems 150 volts to ground and under. Considering that at one point parts of central Europe were 127/220 (think how schuko sockets came about having no polarity), the IEC/VDE/NFC15-100 may have had incentive to mandate 0.4 seconds disconnection times on 127/220 volts systems since an increase in voltage would not require any re-wiring or recalculating of the circuits once raised to 220 volts to ground.
Both the Phillipines, Mexico, Canada and the US use the NEC or NEC based code- however the NEC has no earth fault loop impedance requirements. Meaning I could legally run 2.08mm2 to a shed 2000 feet away and never trip a breaker during a short circuit. All the earth wires in the shed would be at 60 volts to remote earth. I could plug in something metal, have it sit live at 60 volts to ground, get killed, and absolutely nothing could be done to blame the electrician, authority having jurisdiction or the NFPA. Even better a 277 volt light pole in a parking lot. I could run 3,500 feet of 3.31mm2 to a LED light, have a ground fault in the fixture, energize the pole at 138 volts to ground and have it sit continuously 24/7 live without tripping a breaker where a child could hug or lick the post with their tongue during winter. Child dies, case gets taken to court, lawyers litigate away from the real cause taking advantage of everyone lacking basic electrical theory...
Here are two US sparks having seen the problem in their career:
Is there any real danger in using a 0.8 seconds as disconnection time for 150 volts line to ground? Or would a sweet spot at 0.7 seconds work? Call me cheap but I don't want to use 0.4 seconds unless I really have to. https://www.electriciansforums.net/attachments/1574370614127-png.54016/
forums.mikeholt.com
Is there any real danger in using a 0.8 seconds as disconnection time for 150 volts line to ground? Or would a sweet spot at 0.7 seconds work? Call me cheap but I don't want to use 0.4 seconds unless I really have to. https://www.electriciansforums.net/attachments/1574370614127-png.54016/
forums.mikeholt.com
The thing is people, especially children, get killed all the time in the US from energized pools, fences, light poles, AC units, industrial equipment, doors, ect. The blame gets put on shoddy work or poorly connected earth wires... not the code... Much like in the 70s missing bonding jumpers leading to shocks and electrocutions were blamed on ground rods not driven deep enough in the court of law.
The NFPA's solution is to quietly mandate GFCIs on everything- much like GFCIs took care of all the 2 prong metal framed tools injuring people. I encourage you to read the code making panel's reasoning:
NEC 2020 code new standards in GFCI protection - http://www.p3-inc.com/blog/entry/nec-2020-code-new-standards-in-gfci-protection
Ditto for industrial equipment violating earth fault loop impedance:
Learning objectives Understand UL’s new GFCI classes. Understand how GFCIs for 240 to 600 V applications differ from the familiar Class A GFCIs. Know where t
www.csemag.com
Which is why I am so curious about learning BS7671 and establishing a value which can be applied to US systems.
That and the fact the US will eventually one day go to a 230-250 volts utilization voltage. Before (if) 230/400Y becomes the norm 127/220, 133/230 and 138/240Y systems will be common in aiding the conversion process. Its easier to raise a Con Edison 120/208Y network by 10 volts than it is by 110 volts.
But regardless the issue of loop impedance (or lack there of) needs to be addressed first.
