M
moody89
Hi all, I've been a long time lurker on these forums and have found it a great resource and pool of knowledge. Now I'm after a bit of advice myself on something that I don't have a lot of experience with. I've been asked to have a look at installing lighting and socket-outlets in a small barn. I'm confident in doing the work and have done my homework and been through Section 705 in the Regs, as well as searching through these forums for similar posts. The barn is used mainly for storage but does house some livestock.
Basically, the client is having a new electrical supply installed by the DNO in the near future so I'm starting from scratch with the wiring. My main concern is that he has told me that the DNO will be installing a PME system. Having gone through S-705, to my understanding it is not recommended that there be a PME system installed where a metal grid is not installed in the floor. I'm fairly certain that there is no metal grid in the floor on this barn. Would it be worthwhile suggesting tha he contact the DNO and see if they can change to a TN-S system when they install the supply or would I be better to TT it anyway? Browsing through posts on these forums, I've seen quite a few recommendations to use a TT system. As a side-note, I'm pretty sure I understand the reasoning of the earthed metallic grid underneath the floor, but why is it a particular issue if one is not installed on a TN-C-S system? I'd be intrigued to understand this if someone more experienced an offer an explanation!
Obviously, being a barn, it is susceptible to moisture etc and I understand that Section 705 states a minimum of IP44 for all equipment. My understanding of this is that all the socket outlets, light switches, light fittings etc. will need to be at least IP44 and I am assuming that this also includes the consumer unit. Is this correct or will this be overkill? The original plan was that he wanted a large grid switch to individually switch the lights in rows etc or something similar. If so, can this be done and still meet IP44 specs? For those of you who have experience in agricultural work, what type of wiring system would be most suitable? Obviously there is a need for mechanical protection but I've also heard that galv isn't the best option due to moisture etc. I'm also concerned about rodents but I am not certain on what would be the best way to prevent cable damage from rodents whilst also meeting the other needs I mentioned. I was thinking heavy duty PVC conduit or even doing the lot in SWA but I wasn't sure how rodent-proof SWA would be.
Apologies for the essay and for a few questions that may seem obvious to some of you, but as I mentioned, I don't have a lot of experience in this type of work but I am keen to do the job to a high standard and just want to do things right. Thanks in advice for any feedback!
Basically, the client is having a new electrical supply installed by the DNO in the near future so I'm starting from scratch with the wiring. My main concern is that he has told me that the DNO will be installing a PME system. Having gone through S-705, to my understanding it is not recommended that there be a PME system installed where a metal grid is not installed in the floor. I'm fairly certain that there is no metal grid in the floor on this barn. Would it be worthwhile suggesting tha he contact the DNO and see if they can change to a TN-S system when they install the supply or would I be better to TT it anyway? Browsing through posts on these forums, I've seen quite a few recommendations to use a TT system. As a side-note, I'm pretty sure I understand the reasoning of the earthed metallic grid underneath the floor, but why is it a particular issue if one is not installed on a TN-C-S system? I'd be intrigued to understand this if someone more experienced an offer an explanation!
Obviously, being a barn, it is susceptible to moisture etc and I understand that Section 705 states a minimum of IP44 for all equipment. My understanding of this is that all the socket outlets, light switches, light fittings etc. will need to be at least IP44 and I am assuming that this also includes the consumer unit. Is this correct or will this be overkill? The original plan was that he wanted a large grid switch to individually switch the lights in rows etc or something similar. If so, can this be done and still meet IP44 specs? For those of you who have experience in agricultural work, what type of wiring system would be most suitable? Obviously there is a need for mechanical protection but I've also heard that galv isn't the best option due to moisture etc. I'm also concerned about rodents but I am not certain on what would be the best way to prevent cable damage from rodents whilst also meeting the other needs I mentioned. I was thinking heavy duty PVC conduit or even doing the lot in SWA but I wasn't sure how rodent-proof SWA would be.
Apologies for the essay and for a few questions that may seem obvious to some of you, but as I mentioned, I don't have a lot of experience in this type of work but I am keen to do the job to a high standard and just want to do things right. Thanks in advice for any feedback!
