Henly block

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davidbrac

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got a two pole RDL henly block from toolstation for a specific job. Started to install it and found that the terminals  are too small for 25mm. Rechecked specification of block its 100amp and mentions 25mm cable termination.

This meant l needed a 60 miles round trip and 2 hours to pick up another block  Guinness

 
Sometimes, 25mm will only fit if you have a clean cut end without all the strands splayed out.

Personally I never use a 2 pole Henley, I much prefer 2 single poles side by side. I have seen one where the web separating the two blocks was cracked with a danger the 2 poles could touch. Bad design imho.

 
got a two pole RDL henly block from toolstation for a specific job. Started to install it and found that the terminals  are too small for 25mm. Rechecked specification of block its 100amp and mentions 25mm cable termination.

This meant l needed a 60 miles round trip and 2 hours to pick up another block  Guinness
Was it that small that it must have been a 60A   ?      The 100A  are usually rated  up to 35mm  IIRC 

 
It’s 35+ years since I last used a “henly” block. It was actually a DP Wylex unit. Of the five ways per pole, the outer two could take 25mm², the three inner ones 16mm².

I had no problem with the insulated segregation of the two poles and so can’t see where the problem lies with them?

 
Its the 16mm holes that throws everyone .

I seem to remember a royal decree going out that the  (then)  Electricity Boards would be fitting  and upgrading everywhere to 100A   service fuses  so everyone must start using 25mm  tails .  Many existing heads were 60A  ... and the ever present Wylex  wooden fuseboard  only had 60A  terminals on the main switch . 

Now they're reducing to 80A  . 

My big gripe these days is that meter tails are now made from  high tensile steel  instead of soft copper ....its no wonder CU's go into meltdown .   If you tighten the terminals with a socket set and a 4 ft extension bar  the cable in the terminal remains in it's circular shape  where the old copper would  be squashed into place  with much more surface area  making contact. 

I've tightened terminals up to 50,000  lbs per sq. inch  ....then twist the tail and it still  comes loose .       Raise the question ...no one is interested. 

 
It must be worth a few bob to firms whose names become generic  . 

Lucy blocks  ....Henly Blocks  ...   To  Megger a circuit .....to Hoover round the house.        Oh   theres only three  ,  surely theres more  .? 

 
I've tightened terminals up to 50,000  lbs per sq. inch  ....then twist the tail and it still  comes loose .       Raise the question ...no one is interested. 


Well no wonder they can still come out, I think the small print said 50,183 lbs per sq inch was minimum needed. Though I do know many have been rounding down to 50,000 for a very long time,  I believe the confusion came with the imperial to metric conversions, when a lot of old wives tales and rules of thumb crept in to the termination tightness process.

Doc H.

 
I visualise a warehouse  stacked out with  1 way blocks ....I have two in the van  :C    You are in trouble if  you find you are giving them names .  :innocent
Not got around to naming them , yet!

but I think I have sufficient in stock for the foreseeable 

IMG_2119.JPG

at lest 4 layers deep...maybe more

scale the depth off the adjacent ( obviously redundant ) REC2s....they go to the back wall

 
Kerch ....I think we may be seeing you on that Compulsive Hoarding programme  .   I use a small branch of Denmans  for 99% of my needs and I know they would have nothing like that amount of Henleys in stock .    In fact you are creating a national shortage  of them .

Would you have any spare handles for the old Edgecombe Wind- up Meggers by any chance  ?   :innocent   

 
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