isolation required??

[shagbite]

OSG appendix H4 seems to ask for a switch not more than 2m away.
Unless I'm mis-reading it.

remember that the osg is just a guide. bs7671 doesn't really make reference to the 2m rule - not the current edition anyway. bit daft, i know, but that's the iet for you. as long as section 537 of the reg's is being observed, the installation isn't breaking any rules. table 53.4 shows that an mcb can be used for isolation, functional and emergency switching.

 

[MDJ]

The regs are minimum standards, sometimes common sence and professional practice overides them, I'd sack anyone installing a cooker circuit and not a double pole isolator near it for isolation in a domestic situation

 

[shagbite]

The regs are minimum standards, sometimes common sence and professional practice overides them, I'd sack anyone installing a cooker circuit and not a double pole isolator near it for isolation in a domestic situation

i'm with you mate. sadly, common sense and professionalism are rare commodities in this day and age.

 

[dtec dave]

..and to top it off i realised he had used a 6mm cable for a 10700 watt oven!!!

 

[ferg]

I think the osg guidance on this is a hybrid of BS7671 and building regs if I remember correctly, which TBH I probably don't

that oven must be a commercial one then.

 

[Progressing]

314.4 "all appliances should be fitted with functional switching" is that not clear enough??

 

[ferg]

erm... mcb can be used as functional switch.

 

[MDJ]

:26: :4:

 

[dtec dave]

..and so we have another grey area!!

 

[Octopus]

..and so we have another grey area!!

Its not grey, its light black!

 

[Progressing]

Functional control


This control relates to all switching operations in normal service conditions for energizing or de-energizing a part of a system or installation, or an individual piece of equipment, item of plant, etc.
Switchgear intended for such duty must be installed at least:
At the origin of any installation
At the final load circuit or circuits (one switch may control several loads)
Marking (of the circuits being controlled) must be clear and unambiguous.
In order to provide the maximum flexibility and continuity of operation, particularly where the switching device also constitutes the protection (e.g. a circuit-breaker or switch-fuse) it is preferable to include a switch at each level of distribution, i.e. on each outgoing way of all distribution and subdistribution boards.
The manœuvre may be:
Either manual (by means of an operating lever on the switch) or
Electric, by push-button on the switch or at a remote location (load-shedding and reconnection, for example)
These switches operate instantaneously (i.e. with no deliberate delay), and those that provide protection are invariably omni-polar(1).
The main circuit-breaker for the entire installation, as well as any circuit-breakers used for change-over (from one source to another) must be omni-polar units.

onni polar means disconnects All poles

 

[ferg]

Cut and paste for the win.
If you actually read what you were cutting and pasting...

 

[Progressing]

I was actually hoping people would read rather then having to explain simple things like functional switching!

that wasn't being bitchy btw just defending my laziness

 

[ferg]

quoting chunks of the regs is easy.
I would much prefer to see your own interpretation of them.
Then people like me can learn from you.

 

[Progressing]

Ok mate,
The regs state that cooker circuits must have functional switching (cooker switch) the on site guide then backs this up by saying that a cooker switch must be located within 2 metres of the appliance. It's not only the regs that you do it for there is also the practical reasons (you can't reset that bloody alarm I sometimes set by leaning on the cooker) and also testing.

I've only just finished college so I read up as much as I can and usually just scroll around the forum picking up information from new posts. I'm sure I take in information incorrectly sometimes so it's good to be tested on it!

btw that was 4 years of college not 5 weeks