Urgent question re. RCDs

[Andy Hall]

I see. Thing is, there probably is a British Standard in some way or other.

[John Rumm]

A short bit of 25mm^2 tail would do the trick just fine.

[John Rumm]

Another reason why the nonsense of Part P will only serve to encourage accidents. How many people who in the past would have said "I will have the cover off and have a look" may have been dissuaded? Not many perhaps, but it only takes one.

[tony sayer]

In article , Andy Hall writes

Yes, section DD refers...

In this instance:)....

[Dave Plowman (News)]

Trouble is if you look at the pic it's got a crimped terminal at one end.

[Andy Luckman (AJL Electronics)]

What could?

What wires?

Why?

Perhaps if you have a look at this link, it might help:

[John Rumm]

You could take it to the screw terminals on the output of the RCD/Incomer though.

[ARWadsworth]

Or buy a 25mm crimp terminal for about 20p and beg/borrow some crimpers.

Adam

[Sniffy]

Well I'm pleased to say I'm back up and running with a new solution in place and try as I might, I can't hear any arcing going on inside the CU.

It's a long story and I'll save you all the details, but today took me from CEF in Holborn (who "don't get on with MK so if it's not in stock we won't order it from them") via a mythical branch of WF Electrical on Oxford St which didn't appear to exist, then (having returned from the big smoke) I went to TLC in Slough as you suggested.

TLC couldn't help but they pointed me to Rexel Senate in Slough (who I'd never heard of). The man from Senate couldn't help with the spare parts I needed but seemed so ashamed of this fact that he discounted a new MK sentry CU chassis for me down to 10 quid 44p plus VAT.

Having duly taken his arm off I raided the new CU kit to obtain suitable terminal block (which only needed 1 terminal hacksawing off to make the right size) and the neutral link. Unfortunately the neutral link is of a different design and I had to drill a couple of holes to allow the fixing to interface it to the existing bar at the base of the CU. Drilling holes with a mains drill isn't so easy when your CU is in pieces, I can tell you. Memo to boss - the copper swarf on the floor of the office isn't anything to do with me - talk to the other keyholders...

Anyway, enough blather - here's the before and after shots. I know it's not perfect, but it'll do. Thanks to all for all the advice!

Before:

[Dave Plowman (News)]

Think joe bloggs might find it difficult to find someone with a suitable crimping tool?

[Sniffy]

There's always the leg of the mother-in-law's chair if all else fails.

[Andrew Gabriel]

Reminds me of working for GEC many years ago. The company would hardly ever spend money on tools, and our attempts to get a proper tool for putting IDC connectors on ribbon cable was ignored for years. Of course, this just encouraged engineers to come up with even more outrageous ways of putting these connectors onto ribbon cable. One of the first was to carefully lay the connector and cable in their assembled positions on the floor and then stamp on them. After about 20 smashed connectors and a cable that had been trimmed significantly shorter, you would get a good connection. With practice, you could get the failure rate down to about 4 in 5. A variation on this was to align the connector in a similar way at the top of the desk drawer and then kick the drawer shut on it, which improved the success rate, but each desk only did about 10 connectors before some critical bit (like the top of the wooden drawer front) broke off. I think the most refined method eventually adopted was to carefully position the connector in the hinge of a door, and carefully close the door just enough to pop the connector together. This could achieve a better than 1 in 2 success rate with practice.

The funny thing is I found myself putting this into practice for real on a customer machine (a Videotex system being installed in Yugoslavia about a month before the country dissolved into civil war). There I am in Lubiyana for the day to install the system, which won't work because a ribbon cable has been torn at the end in transit. No chance of obtaining a replacement for one of our proprietry cables that day. Managed to get the connector cleanly off, and a cleanly cut cable end. This leaves me with a ribbon cable end and a connector to assemble, and not a hope in hell of getting an IDC assembly tool (it took an hour for someone to find us a pair of scissors to cut the cable end square). I can't take the ribbon cable out of the system (it's threaded with about 20 other cables through 2 other 19" rack cabinets). I can just get the end to the floor, so it will have to be the stamp on it method. I only get one chance, as I only have the connector I took off. Still, it seems all that practice paid off -- with very careful positioning and aiming, it worked first time. The Yugoslave PTT staff there were even more amased than me.

It was a long day, but when I left, they had a working system. Maybe there was some method in the madness of not buying us tools at GEC after all?

[Dave Plowman (News)]

If you mean the sort of cable and connectors you get for say IDE HDs, I just use a vice. Works every time.

[Andrew Gabriel]

So do I at home (have even used B&D workmate jaws).

[ARWadsworth]

Maybe. But you could buy one for less than an electricians call out fee.

Adam

[Andy Hall]

That's a pain though - you'd have to unplug it....

[Dave Plowman (News)]

Possibly true, but few - apart from us - think like that, ;-)