new power socket by outside door?

[JohnW2]

Also the directive given by BS7671 states that only one spur per socket and the number of spurs must not exceed the number of sockets on a RFC.

I keep saying that being said, but I'm not sure where BS7671 itself says those things.

The OSG says that the number of fused spurs is umlimited, but that the number of unfused spurs should not exceed the number of sockets on the ring. However, even the OSG does not seem to say anything about 'only one spur per socket' (I presume you mean that one can't take two spurs off the same socket or accessory). I accept that it may be impractical (things would get very crowded with 4 cables, even if one could find a socket with terminals rated to take 4 cables), but I can't find anything about it in either BS7671 or the OSG.

As a matter of interest, the OSG also says that 'as a rule of thumb', the cable length of unfused spurs should not exceed one eighth of the cable length from the spur to the furthest point in the ring (which could be an issue for the OP).

Kind Regards, John.

 

[PrenticeBoyofDerry]

appendix 15

 

[JohnW2]

appendix 15

Needless to say, that's what I was talking about, since that's the only part of BS7671 (albeit only an 'informative' Appendix) which says anything about details/arrangements of ring finals

However, my question remains - where does Appendix 15 (as opposed to the OSG) say anything about the number of spurs on a ring or the the number of spurs from a socket?

Kind Regards, John.

 

[very_pointy_ears]

Have you thought about just drilling a small hole and having the PSU for your cat flap in the kitchen, and run the ELV cable through the wall.

It would be a lot less hassle.

Hmm yes true, I hadn't really given that much thought. It does tie up a socket in the kitchen but it's one that usually doesn't have anything plugged into one half of anyway. The toaster is permanently plugged in to one side but the bread bin doesn't require power

I'd have to cut and re-join the ELV cable as the end has a 90 degree jack on it so poking that down a hole would be awkward. That probably kisses goodbye to any warranty but I suppose most of the time these things don't go wrong in the warranty period anyway.

Having said all that, I'm still tempted by the socket option as it keeps it all tucked away in the porch and makes it easier to remove the unit again should we decide to.

3) Mains with battery backup (sensible option!)

Same here. The one we've gone for is the Petporte. Although it can run purely off battery, as you said there is the problem of the battery running out. What's more, when running off battery it's slower to unlock because the cat has to nudge the flap first to turn on the chip reader, whereas with the PSU it's always scanning. Cats are fickle creatures at the best of times and I wouldn't be surprised if they give up and consider themselves locked out if it didn't open after the first nudge.

where would the plug in flex go and how does this effect the safe opening of the door in regards to the safety of the cable?

The flex enters the unit at the bottom, on the inside half. It's a bit of a pain to route neatly, really. I'll have to run it along the door and then do a flex loop near the hinges before running it up the side towards the PSU. The flex loop on ours is going to have to be unusually big to accomodate the hinge movement because this door, unusually, is hinged on the outside, so quite a wide gap opens up where the cable will be routed.

I had thought about concealing the cable around the edge of the door such that it would be hidden between the door and frame once the door is closed, but that's going to be a lot more hassle to do and I'll have to be far more careful with the flexing by the hinge side, ensuring there's enough slack whilst not too much such that the cable gets pinched when the door shuts.

 

[ban-all-sheds]

1) Battery only (cat gets locked out or flap fails to open mode when battery runs out)

The cat will survive.

2) Mains only (as above if power fails)

As above.

Or you could always do the decent thing and get rid of the animal.

 

[very_pointy_ears]

I've had a quick look behind the socket. There's plenty of room in there. There's a 35mm back box that, due to several layers of plaster is actually set about 7mm in from the face of the wall so it's effectively a 42mm back box.

Looks like a choc block will be an easy fit.