GS23 Electrical safety on schools

[Phoenix]

Anyone got a copy of this?, I understand that it has been withdrawn, but that the HSE state they still stand by the guidence contained within

 

[Sidewinder]

What information are you after?
Is GS23 adequate?

 

[Sidewinder]

@Phoenix?

 

[Phoenix]

Sorry, Absent mindedness (beginning to think I have ADHD, but thats another story)

Not so much in need of it now, because I managed to write the document without it in the end. But was dealing with a situation where the question was being asked about whether the safe supply 'Blakley' units could be removed from school science labs and replaced with 30mA RCDs, I wanted to check that they had indeed been an official HSE recommendation, as I was relying on a paragraph from a manufacturer's site which referenced that the GS recommended them.

Anyway, how are you SW? Health issues being kept in check?

 

[Sidewinder]

@Phoenix, those Blakely units were sometimes 30mA, 10 mA and/or safety isolation transformers, depending.

So sometimes they can be swapped out for a 30 mA other times not.

 

[Sidewinder]

Health wise I am coping.

Pain has reduced, mobility has increased a little from total paralysis.

The cancer is incurable though.

 

[Phoenix]

@Phoenix, those Blakely units were sometimes 30mA, 10 mA and/or safety isolation transformers, depending.

So sometimes they can be swapped out for a 30 mA other times not.

The units in question are double wound transformers, centre tapped to earth through a 12K wire wound resister, so limiting shock voltage between line and earth to 115v and current to sub 10mA combined with a 1.25mA earth leakage device (actually a 5mA sensor, but the circuit is wound through it 4 times so to multiply the value that the sensor reads.

I just made the point that they'd be swaping a system that physically limits shock currents to 10mA and disconnects at 1.25 for one that simply disconnects at 30ma (with no limit on the magnatude before it trips), so reducing the level of protection, and that this might be problematic with the wording of 4(2) of EAWR which requires systems to be maintained to prevent danger as far as reasonably practicable, it would be tough to justify that not removing existing systems was not reasonbly practiable measure, should any accident with mains powered lab equipment happen. Duty holders decision at the end of the day, but they now have an understanding of the benifiets of these units

 

[Sidewinder]

So the isolation transformer type then.