Rules and Guidelines
Want to participate in the discussions? Please read our Community Rules and Guidelines. Need some help? Visit Support and Answers.

  • State Not Answered
  • Locked Locked
  • Replies 39 replies
  • Subscribers 27 subscribers
  • Views 3496 views
  • Users 0 members are here
Options
You may also be interested in
This discussion is locked.
You cannot post a reply to this discussion. If you have a question start a new discussion

Wiring PIR sensors, Extractor fans, LED panel lighting, overide switch. In one circuit

Former Community Member
Former Community Member
Hi,


I am currently level 2 Qualified 2365 and beginning my level 3. 

​​​​​As my interest in the field increases I always observe electrical installations, I noticed one day in a public toilet, the ceiling panels were lifted and the Extractor fan, PIR sensor, Panel lighting, and override switch we're all wired in one circuit using wago connectors. 

Now I can't help it but I really need to work out how this was wired in a wiring diagram, I have an idea as to how, but not sure.


But my question is, as normal do we calculate the whole load of this circuit and then use the correct rated mcb, and if anyone could provide me with a wiring diagram or explain how it works. I think I even noticed some resistors used. 


Thanks for your help
Parents
  • 0

    Although in the real world. will a 3A fuse blow before a 6A MCB would?



    It's possible. On the wiring side we tend to think of faults being of negligible impedance, but once you're inside an appliance, possibly on the far side of some controlling electronics, things can look rather different. The current due to a fault can be limited by how far down a motor winding a short occurs or the constrained by rapidly warming semiconductors. Certainly the fuse would open long before the MCB for currents in the 4A-7A range.


       - Andy.
Reply
  • 0

    Although in the real world. will a 3A fuse blow before a 6A MCB would?



    It's possible. On the wiring side we tend to think of faults being of negligible impedance, but once you're inside an appliance, possibly on the far side of some controlling electronics, things can look rather different. The current due to a fault can be limited by how far down a motor winding a short occurs or the constrained by rapidly warming semiconductors. Certainly the fuse would open long before the MCB for currents in the 4A-7A range.


       - Andy.
Children
No Data

Join us to get the best from IET EngX.

Joining EngX lets you personalise your experience so you stay up to date on the topics that interest you, plus you’ll be able to make connections who are looking to collaborate, exchange ideas and more.

Join us Not now

Community Rules & Guidelines