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 11 replies
  • Subscribers 26 subscribers
  • Views 1446 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

SELV - Not a fan of?

whjohnson
Short question - is a mains voltage extractor fan permissible in zone 1 or 2 in a bathroom provided it is protected by a 30ma rcd and that all IP requirements are met??

OSG chapter 8, Table 8.1, page 94 says only 25vAC or 60v ripple-free DC SELV or PELV, yet I have just been to the wholesalers to look at what they have, and they showed me two mains fans with "Suitable for" or "Complies with" Zone 1 emblazoned on the packaging.


I am looking to fit a fan with a humidistat but am struggling to find a SELV version if that is actually required.

So, which is correct? The manufacturer (whose instructions must be followed) or the on site guide, whose instructions must also be followed!


Comments welcome.


Parents
  • 0
    As Andy has pointed out, Regulation 701.55 clearly says "ventilation equipment" is permitted in Zone 1, specifically listed as item (viii), provided the manufacturer says it's suitable for installation in Zone 1. It does not have to be SELV, but 701.411.3.3 requires a 30 mA RCD for additional protection.


    Any switchgear and accessories for the fan, however, would have to go outside the zones (not even permitted in Zone 2).


    Table 8.1 on the 2018 OSG that you highlighted, in Zone 1, column 3, after SELV/PELV sentence, has another sentence about which mains powered fixed equipment is permitted - and ventilation is, as Farmboy has pointed out, clearly listed. The 4th column only refers to swtichgear and accessories - and as I have pointed out, if mains, the switchgear and accessories (fan isolator, other switches, FCU etc as applicable to how you're wiring up) would have to go outside zones.
Reply
  • 0
    As Andy has pointed out, Regulation 701.55 clearly says "ventilation equipment" is permitted in Zone 1, specifically listed as item (viii), provided the manufacturer says it's suitable for installation in Zone 1. It does not have to be SELV, but 701.411.3.3 requires a 30 mA RCD for additional protection.


    Any switchgear and accessories for the fan, however, would have to go outside the zones (not even permitted in Zone 2).


    Table 8.1 on the 2018 OSG that you highlighted, in Zone 1, column 3, after SELV/PELV sentence, has another sentence about which mains powered fixed equipment is permitted - and ventilation is, as Farmboy has pointed out, clearly listed. The 4th column only refers to swtichgear and accessories - and as I have pointed out, if mains, the switchgear and accessories (fan isolator, other switches, FCU etc as applicable to how you're wiring up) would have to go outside zones.
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