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 4 replies
  • Subscribers 32 subscribers
  • Views 415 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

Din Rail devices in domestic home

Former Community Member
Former Community Member
I wish to install a Siemens Logo PLC+additional modules to control my home heating system. This is a DIN rail device does this it have to be mounted in a BS7671-3 compliant enclosure? If the enclosure also include a 10A MCB for protecting the input supply cable and 3A MCB for protecting the relays, would this change the answer? Only one mains electrical circuit will be going into the box, it will be providing the power of a small electric underfloor heating system, circlation pump for wet underfloor heating, and power for valves to provide zone based heating control.


It would have been nice to use a enclosure with a window so the display of the logo could be seen without opening the enclosure, or perhaps being able to ventilate the box as it will have a 1.3A 24V power supply in it to power the automation. Both of which do not seem allowed with a fire proof BS7671-3 enclosure.
Parents
  • Former Community Member
    0 Former Community Member
    Its not directly wired back to the the CU, but rather on a spur from the ring main, I always like to have all spurs fused, as second owners can have a habit of replacing a single socket with a double or worse. Having an FCU wired into the wall would be my normal approach. But as the easily available sizes of fuses are 3, 5 and 13A. So if it were to blow (not that i think it ever would), the likely hood would be someone would shove in a 13A fuse. Hence I felt a 10A MCB might be safer option, as that is the rating on the relays for the LOGO, the extension unit relays are however only rated at 3A, hence why i said 2. Perhaps I will just do both being a belt and braces kind of person.
Reply
  • Former Community Member
    0 Former Community Member
    Its not directly wired back to the the CU, but rather on a spur from the ring main, I always like to have all spurs fused, as second owners can have a habit of replacing a single socket with a double or worse. Having an FCU wired into the wall would be my normal approach. But as the easily available sizes of fuses are 3, 5 and 13A. So if it were to blow (not that i think it ever would), the likely hood would be someone would shove in a 13A fuse. Hence I felt a 10A MCB might be safer option, as that is the rating on the relays for the LOGO, the extension unit relays are however only rated at 3A, hence why i said 2. Perhaps I will just do both being a belt and braces kind of person.
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