Main switch height and location

**ians** · 16-Oct-19, 07:28 AM

So i have had a few encounters with "new owners" with regards to the height and location of the main switch.

" 6.6.1.6 any point of the DB that has to be reached shall not exceed a height of 2.2 m above FFL or (walking level)" This is where it gets interesting ...to the bottom of the DB ...the middle of the DB...the bottom of the main switch.

The first incident... the DB height from FFL to the middle of the main switch 2230 mm...so i made a wooden step 100 mm high and secured it to the wall directly below the DB...new owner moved in and complained about the DB height...i produced a picture of the platform which had been removed...because they couldnt fit the fridge in the location in front of the DB...and thats how the fight started...my argument is the fridge shouldnt obstruct access to the DB and the DB was installed long before the clever cupboard designer conveniently placed the fridge in front of the DB.

The next incident... the DB is 2240 mm to the middle of the main switch which by the way seem to be about the height that most DB were installed around the same time...i just left it and issued the COC...40 mm...really you gona make a person go to all the trouble of installing a piece of trunking 16 mm wires an extension box and a new main switch...for 40 mm
The DB was installed...50 plus years ago.

If anyone wants to fix this DB problem...consideration should be more focused on the location and surroundings...space in front of the DB...accessibility and more important issues.

If someone wants to make a law ...all DBs should be mounted in a passage behind the door when it is open at around eye level (5.5 to 6 ft) not arms reach ...so that when the door is closed ...there are no obstructions in front of the DB and short people can reach it.

It should be illegal to mount a DB in the kitchen...especially behind a fridge in the cupboard even if it is only 1999 mm to the middle of the main switch.

I suggested a customer fit a picture frame or a cupboard (150 mm deep) dedicated for the DB...the person told me it is against the law to mount a DB in a cupboard...well i just smiled.

**Leecatt** · 16-Oct-19, 08:23 AM

My understanding of this section is that the entire main switch needs to be less than 2200 mm from the floor.
The walking level is just that, the walking level. I don't think that a step can be included in the Walking level.
Just my 5 cents worth

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**ians** · 16-Oct-19, 04:37 PM

Originally Posted by Leecatt

My understanding of this section is that the entire main switch needs to be less than 2200 mm from the floor.
The walking level is just that, the walking level. I don't think that a step can be included in the Walking level.
Just my 5 cents worth

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This is what these platforms are all about...sharing our 5 cents worth.

The step by the way was actually a platform which filled the space where the fridge was suppose to stand...my 5 cents worth is that the fridge shouldnt be in front of a DB even if the DB is mounted at 1.5m

**ians** · 18-Jan-20, 06:19 PM

Had to read the new sans book today ...had to issue a COC and had a disagreement with the tenant...so i had to dust off the book and browse for the correct clause.

Imagine that... according to page 148 caluse 6.6.1.6 "any point of distribution board that has to be reached during normal operation shall not exceed a height of 2.2 m above the floor (or walking level)"

we could sit and argue about "walking" ...a platform built to bring "any" part of the DB within 2,2 m would be hard to challenge

.

**mygoggie** · 19-Jan-20, 12:24 PM

@ian, I do not clearly understand your last sentence about "to challenge" but I did check on the definition of floor and walking levels and it is as I said above.

This clause for an Engineer such as myself means that FFL or walking level is the Final Floor Level. That is the final finished concrete level without tiles or carpet of the floor at the DB. This does not include a step, platform or such as this is not part of the floor nor can you walk on a step or platform.

**ians** · 19-Jan-20, 04:35 PM

Originally Posted by mygoggie

@ian, I do not clearly understand your last sentence about "to challenge" but I did check on the definition of floor and walking levels and it is as I said above.

The SANS book refers to the "the floor (walking) level" ...including platforms... tiles... carpets and everything else... think about it... you would only need to reach the DB once all those items are installed... i work in places where the DB is mounted 5 metres above the FFL ...we have platforms and walkways mezzanine floor etc between the FFL and the DB... The COC is only required once the construction of the building and all the finishing are completed.

FFL - Finished floor level is a term used in the construction industry... for construction.

**adrianh** · 16-Oct-19, 05:22 PM

My DB is mounted high up in a cupboard, behind a shelf, in the deep dark corner of the scullery next to the tumble dryer which stands above the washing machine . (I tossed the shelf)

I am 173 cm tall and due to the kitchen counter it is hard to reach the thing. I agree, the DB should be mounted exactly as Ian described - it is a damn pain to go rummaging to the thing in the dark especially when there are washing baskets in the scullery as well.

One shouldn't have to struggle to get to it - especially in an emergency.

(And of course ESKOM has now taken up load-shedding again so we are back to faffing with our electricity supply)

**mygoggie** · 23-Oct-19, 03:18 PM

This clause for an Engineer such as myself means that FFL or walking level is the Final Floor Level. That is the final finished concrete level without tiles or carpet of the floor at the DB. This does not include a step, platform or such as this is not part of the floor nor can you walk on a step or platform.

Secondly the clause is quite clear in that it states "any point of the DB that has to be reached during normal operation" which means you must be able to reach to any point of the DB, which in my understanding will be the topmost activator of an isolator, CB or switch installed in the DB. However you can install the DB higher if the DB's supply switch-disconnector is LESS than 2,2m above the FFL or walking level. In my opinion I would like to see the activators of the top row of switchgear/equipment in a DB at less than 2,2m from FFL.

Regarding the fridge in front of it, Clause 5.2.8 Positioning and accessibility of electrical equipment applies. Section (b) and (c) states clearly that access to the DB should be "it is readily accessible for installation, replacement, operation, testing, inspection, maintenance and repair" and "there is easy access to its location". Also (f) where the distribution board is concealed by a cupboard or other covering, the notice for live electrical apparatus referred to in annex Q shall be in a conspicuous place indicating the position of the distribution board. If there is a fridge in front of the DB the installation will not comply with Clause 5 and you should therefore cancel the CoC of the premises.

Secondly with a fridge in an enclosure with the DB behind it you will get elevated temperatures and then 6.6.1.4 The distribution board shall be suitable for the environmental conditions in which it operates. will become applicable as well as your wiring and switchgear temperature tables.

Also 6.6.1.9 Distribution boards shall be so positioned and arranged as to ensure safe operation and maintenance. No safe operation if you cannot get to it in time.

My 10c worth from a practical point of view. Rather stand on the regulations and be safe than trying to accommodate someone else's whims and ignorance.

**ians** · 20-Jan-20, 07:48 AM

From personal experience and 30+ years in this industry and having to deal with cabinet installers and their lack of consideration for anybody having to carry out maintenance on other services... my advice is to install a DB behind the door in a passage at eye level height or just above... it is the most practical position i have seen for a DB.

While on the subject of smart locations... alarm panel and CCTV equipment should also be installed above the passage door... slightly away from the wall so that the wiring can be installed via the knockout intended for the wiring in the middle of the panel ...so that the wiring doesnt look like something the dog dragged out your grannies knitting bag and then you tried to hide it by shoving it into a panel... if your workmanship is so shoddy that you have to hide it behind a cover ...you can always clip a board over.

**AndyD** · 24-Oct-19, 10:15 AM

I'm not sure that a built-in fridge in front of a DB would cause ambient temperatures that would be a hazard. Circuit breakers are generally designed to safely operate in temperatures up to 50 or 60 degrees celsius and as high as 75 degrees for some devices. Even above these temperatures they still operate safely but a 'derating' factor may need to be applied due to inaccuracies creeping in on the thermal tripping curve. The inaccuracies will be in the safe direction where the breaker trips at a lower current than its rating so high ambient temps will just result in possible nuisance tripping rather than a possible overload. I don't think a built-in fridge could ever produce temperatures that would cause overheating damage to a DB.

If the fridge was moveable without needing tools I'd usually class the DB as readily accessible. This wouldn't be the case however if the cupboard door needed removing first.