Test Equipment Anonymous (TEA) group therapy thread

[Specmaster]

For those not familiar with the Crabtree Safety lamp holder I referred to earlier, I have these photos that I made notes on to help understand what make them safety type. As far as I know, most other lamp holders from other makers now use a small nylon locking screw to help retain the terminal in place. This is needed as many of us will have experienced at some point that when it comes around to removing the lamp shades for cleaning, fitting new ones etc, often the shade ring is hard to unscrew and the terminal cover unscrews exposing the incoming supply. This is less than ideal.

That screw is there because regulations require the use of a tool to gain access to any terminals, but what happens when, if once that screw has been removed and is not refitted, the lamp holder then no meets wiring regulations 

Crabtree thought at the time these regulations were being drafted, it would a good time to redesign the lamp holder and make it as safe as it could be. I won't go back over what I have already mentioned in previous posts about just how dangerous the humble lamp holder really is, and most people do not appreciate that fact either.

I think the pictures are pretty self-explanatory, but any questions arising, please ask.

[Cerebus]

Just back from nipping to the shops before they close, to say I got a little wet doing so would be litotes. Two or three miles away:



(That's the exit from the North Circular (A406) to Walthamstow, for those who know my manor.)

[bd139]

You're not supposed to drive down the canal 

Fire? 

Why did that sound so hopeful...? 

* Are you really that bored...? *

Yes 

[McBryce]

What could POSSIBLY go wrong...?   

mnem
 

The list is too long for this forum I'll compile it in an excel file and send it to you on a DVD.

McBryce.

[mnementh]

What could POSSIBLY go wrong...?   

mnem
 

The list is too long for this forum I'll compile it in an excel file and send it to you on a DVD.

McBryce.

It could be worse... I could be using these packs for what they're made for: powering hoverboards.

mnem

[Specmaster]

Just back from nipping to the shops before they close, to say I got a little wet doing so would be litotes. Two or three miles away:



(That's the exit from the North Circular (A406) to Walthamstow, for those who know my manor.)

Arh yes, thats the dreaded A406 / A104 junction, I mean it's not as they didn't know that they had a dip under that underground railway bridge is it and that unless they gave it plenty of pumping power and drains it would become a big lake 

[Cerebus]

Arh yes, thats the dreaded A406 / A104 junction, I mean it's not as they didn't know that they had a dip under that underground railway bridge is it and that unless they gave it plenty of pumping power and drains it would become a big lake 

I don't think anything would have helped them there today - the Romford Road in Stratford/Forest Gate was turning into a lake when I went out (And as always, despite only 20 foot visibility, there was some dick in a black SUV driving along behind me without any lights on).

[Specmaster]

<snip>

It could be worse... I could be using these packs for what they're made for: powering hoverboards.

mnem

Those things are bloody deadly in more ways than one, I just wonder how many people fell and smashed their head on objects on the way down 

[mnementh]

You're not supposed to drive down the canal 

Fire? 

Why did that sound so hopeful...? 

* Are you really that bored...? *

Yes 

I knew it.      

mnem
Seriously... I did.  Maybe I've been hanging around here too long...

[Specmaster]

Arh yes, thats the dreaded A406 / A104 junction, I mean it's not as they didn't know that they had a dip under that underground railway bridge is it and that unless they gave it plenty of pumping power and drains it would become a big lake 

I don't think anything would have helped them there today - the Romford Road in Stratford/Forest Gate was turning into a lake when I went out (And as always, despite only 20 foot visibility, there was some dick in a black SUV driving along behind me without any lights on).

Yeah probably not, considering, as I had pointed out on other posts, the drains etc are all flowing into existing sewers which are possibly centuries old and already overwhelmed. It's time local authorities and governments took a long and serious look at the problems created by such floods and invested in some major upgrades to handle the demand for better drainage.

[med6753]

And then some places in the UK allow ring circuits. Absolutely asinine and IMHO dangerous. Yes, we have some dumb things here like non-polarized outlets and plugs but at least the wiring in the walls can withstand full rated current.   

The house we are in now  was rewired about 10 years ago.   At least it has proper grounding and  RCD (ground fault) protection.     The sockets are on a ring circuits.    I did some checks and everything appears to be ok.

I'm not too worred about it since the plugs all have fuses.

I guess that's the saving grace that the outlets are fused. Because the wiring size for the total current that could be carried in the circuit seems to be under sized. And if ring circuits are so great how come, to my knowledge, does no one else use them or allow them? 

[bd139]

The ring is fused / breakered at the consumer unit (30/32A) and the devices are fused at the plug (13/10/5/3A). Not sure I get what the problem is?

[tggzzz]

Trivia time: what wallpaper should I use on my phone?

Constraint: 320 high, 240 wide. Yes, it is a phone, not a computer with a phone as an afterthought.

Was a hard choice, Tant or RIFA?

Tempting, but I would prefer something more, um, inspirational.

[bd139]

Trivia time: what wallpaper should I use on my phone?

Constraint: 320 high, 240 wide. Yes, it is a phone, not a computer with a phone as an afterthought.

Was a hard choice, Tant or RIFA?

Tempting, but I would prefer something more, um, inspirational.

I haven't seen any inspirational art recently so will substitute this.



 

[Cerebus]

Those things are bloody deadly in more ways than one, I just wonder how many people fell and smashed their head on objects on the way down 

"Think of it as evolution in action." - Robert Heinlein

[Andrew_Debbie]

And what is wrong or dangerous with ring circuits?
Until the latest wiring regulations they were the norm. Now we are allowing spur circuits. The cynic in me says it's to give the equipment manufacturers and electricians more work.

That wasn't me.   I accept things the way they are done here. 
 Except for the light bulbs sockets which make no sense at all.   

[McBryce]

Trivia time: what wallpaper should I use on my phone?

Constraint: 320 high, 240 wide. Yes, it is a phone, not a computer with a phone as an afterthought.

Was a hard choice, Tant or RIFA?

Tempting, but I would prefer something more, um, inspirational.

Well it might inspire you to replace the RIFA cap in some piece of equipment you just bought?

McBryce.

[Cerebus]

The ring is fused / breakered at the consumer unit (30/32A) and the devices are fused at the plug (13/10/5/3A). Not sure I get what the problem is?

And add that every outlet is served by two lays of cable, thus halving the chance of serious faults (e.g. loss of PE conductor). I guess Med's problem is that he's imagining how it works rather than knowing how it works. Two paralleled runs of typically 2.5mm² wire on a 30A circuit, that's the equivalent of 10 AWG, which according to the US NEC is rated at ... 30A. And let's not forget that that's 30A at a proper British 230-240V which represents 6.9-7.2 kVA rather than the wimpish 3.3-3.45 kVA that it would in Med's world.

[mnementh]

mnem

[AVGresponding]

I'm not sure which surprised me more.  Finding these in the house, or that the hardware store in the village had a good stock of fuse wire.

Rewireable fuse consumer units haven't been fitted for 40 years or more.

I don't think you could sell a house with one nowadays; the mortgage company wouldn't lend.

Nope, I don't think that a 60W candle lamp is excessive for a lamp holder to handle without the pins sinking into the solder, I even replaced the lamps with 40W candles with the same results after a few years of use. This is a very common failure mode, especially when the lamp hangs down, as all the heat is then concentrated in the base of the lamp, directly beneath the solder pads.

The BC design goes back a ways, and a typical candle lamp back then would probably be no more than 15 or 20W. Candle lamps have a much poorer heat dissipation rate than a standard shape, which would have been likely 60W maximum back then too.

If you want to exceed those ratings you really need a heavy duty holder, ceramic or metal. The amp ratings are very misleading; a cheap shitty ceiling rose or pendant will be rated for 3A, but if you run a 720W lamp in it, it's gonna get more than hot...
The better quality ones like Crabtree and some MK lines for example will have a maximum wattage rating.

I've run 150W lamps in an enlarged standard envelope shape in standard pendants without issues, the only time I've had the pins sink into the solder was with a 250W lamp...

[AVGresponding]

And what is wrong or dangerous with ring circuits?
Until the latest wiring regulations they were the norm. Now we are allowing spur circuits. The cynic in me says it's to give the equipment manufacturers and electricians more work.

Spur circuits have always been allowed, with certain stipulations. They are different to radial circuits, which is what I believe you meant.

Big Clive shares your conspiracy theory, and I'm not sure I disagree with him...

[mansaxel]

I guess Med's problem is that he's imagining how it works rather than knowing how it works.

Until I understood it I also was confused. Now I'm not. It makes sense, in a way. And it's done that way in HV local nets too. Probably with more sectioning equipment, though.

Power-related:

I'm planning my on-stage power distro system, since I'm the only one thinking about such things. At the bottom-feeder level I'm working in wrt. live sound, everything is a challenge. Like finding an outlet for the alleged talents electronic equipment.

My idea is to create a little orgy of Schuko (CEE 7/3) outlets and IEC 60309 (MK Commando to UK people) 16A connectors. And to saturate the stage with outlets so it is easy and practical to connect things.

If I find a suitable step-down transformer, I'm tempted, just for the fun of it, to build a US-compatible (although not 60Hz) distro system too, of course using the "-4H" group of IEC60309 connectors in yellow. (like at a UK construction site.)

I wonder if one can beat a variable frequency drive into being a 208V 60Hz three-phase grid..

[mansaxel]

TE: Currently watching a -hp- function generator and another (would be 3rd) 8060a. Both are low bids now. Will probably take off.

[Robert763]

Had  bit more experience with ebay's new system. Had a refund (the Huskey FS3s came poorly packed and smashed the base unit) took a week to get to my account. Papal was instantly available. Just sold an item to the EU. No idea what th buyer paid but ebay charged the fees based on 120% of the selling price plus postage. Then added extra for non UK sale. All in all they took about 20% of the auction price and shipping.
Looks like they really don't want private sellers anymore.

[Robert763]

And what is wrong or dangerous with ring circuits?
Until the latest wiring regulations they were the norm. Now we are allowing spur circuits. The cynic in me says it's to give the equipment manufacturers and electricians more work.

Spur circuits have always been allowed, with certain stipulations. They are different to radial circuits, which is what I believe you meant.

Big Clive shares your conspiracy theory, and I'm not sure I disagree with him...

My bad, I did mean radials.
One advantage of rings is more consistent voltage with load position. Useful for measurement labs and TV lighting people like them.  All the lights hve the same color temperature. On a radial the voltage drop as you go further away from the source.