For an underfloor/raised busbar system, what is a typical maximum distance for tap-off points?

For an underfloor/raised busbar system, what is a typical maximum distance for tap-off points?

• A. Around 20 metres
• B. Around 5 metres
• C. Around 50 metres
• D. Around 100 metres

Answer: (A)

Tap-off spacing in a busbar trunking system is driven by keeping voltage drop and heat under control while still staying practical to install and maintain. For underfloor or raised busbars, placing tap-offs about 20 metres apart helps ensure the furthest outlets still receive acceptable voltage under load without needing oversized busbars or an excessive number of joints. If taps were spaced much farther apart, voltage drop at full load could become unacceptable and heat buildup along the run could be higher, especially in a raised-floor setup where cooling isn’t as direct. Shorter spacing, like 5 metres, would mean many more tap-offs and higher cost, while 50 or 100 metres would risk poor voltage regulation. So around 20 metres is the typical maximum distance.

Tap-off spacing in a busbar trunking system is driven by keeping voltage drop and heat under control while still staying practical to install and maintain. For underfloor or raised busbars, placing tap-offs about 20 metres apart helps ensure the furthest outlets still receive acceptable voltage under load without needing oversized busbars or an excessive number of joints. If taps were spaced much farther apart, voltage drop at full load could become unacceptable and heat buildup along the run could be higher, especially in a raised-floor setup where cooling isn’t as direct. Shorter spacing, like 5 metres, would mean many more tap-offs and higher cost, while 50 or 100 metres would risk poor voltage regulation. So around 20 metres is the typical maximum distance.