All devices on 3phase board tripped simultaneously

[Chris White]

A customer recently lost power to part of their electrical installation. On arrival I found all IEC 60947-3 devices had supposedly tripped - including the main switch rated at In 400A. Excluding the possibility of someone tapering with the board, can anyone think of any other reason why this may have occurred?

 

[snowhead]

It seems the OP isn't paying heed to your question.

Sure looks that way,




I wonder if the O.P remade the 400a Mainswitch and survived and or all the other tripped devices?

 

[Chris White]

Is the main switch 60947-2 or 60947-3.

 

[Chris White]

Is the main switch 60947-2 or 60947-3.

The main switch is a 60947-3 with In of 400A.

 

[westward10]

Well that answers that if the main switch is 60947-3 then someone has manually isolated it.

 

[Chris White]

Some

Leaving the main switch aside, unless something simultaneously affected every single distribution circuit between this board in question and the downstream boards, it surely has to be manual operation.

What sort of cables are feeding the downstream boards, are they mechanically protected?
I have once found several circuits all chafed on poorly installed metal trunking which then got hit causing it to cut into all of them.
I think I'd IR a couple of the distribution circuits, rule out cable damage, and declare that the only logical reason is manual operatiomajority of the of the cables are SWA properly glanded into the top of the board.

Leaving the main switch aside, unless something simultaneously affected every single distribution circuit between this board in question and the downstream boards, it surely has to be manual operation.

What sort of cables are feeding the downstream boards, are they mechanically protected?
I have once found several circuits all chafed on poorly installed metal trunking which then got hit causing it to cut into all of them.
I think I'd IR a couple of the distribution circuits, rule out cable damage, and declare that the only logical reason is manual operation.

The majority of cables are SWA properly glanded into the top of the board and going off in different directions to different parts of the building.

 

[Chris White]

Well that answers that if the main switch is 60947-3 then someone has manually isolated it.

I thought a 60747-3 could incorporate overcurrent protection and that the In was the devices rating. Please forgive my ignorance if this assumption is wrong.

 

[westward10]

I thought a 60747-3 could incorporate overcurrent protection and that the In was the devices rating. Please forgive my ignorance if this assumption is wrong.

No if it incorporated trip functions it would be 60947-2 and also with a device of that size it can be adjusted, I assume it doesn't have these features.
What is the part no to be doubly sure.

 

[davesparks]

Yes you are correct. 60647-3 is an isolator whereas 60947-2 is an mccb often used as main switches on panel boards.

60947-2 covers MCB, MCCB and ACCB

 

[Avo Mk8]

That appears to be a Hager H301E which is a switch 'disconnector Isolator'. In which case it does say IEC 60947-3 on the front.
It has a "push to trip" button, but I think that is a mechanical trip for turning off the switch, not current operated.
In which case the only way it will switch 'off' is someone operating it.
Can anyone confirm?

 

[nicebutdim]

Couldn't swear to the H or the 1, but I'd be inclined to go with HC301E, which Hager designate as 'non auto'.

Beyond my experience, but here's a link to some data from Hager. Page 3.30 gives a limited amount of information, but does state BS EN 60947-2 on the table in which this is included. Despite this, every image I can find of this isolator does indeed state 60947-3.

Clear as mud.

 

[marconi]

Well I am going to ask - what is the nature or purpose of the site? Who can walk pass and reach this switchgear? Is it a happy workforce?

 

[Chris White]

It’s a care home. The board is not readily accessible, but not impossible to get to by any of the staff. Please see a close up of main switch - I’d love to determine whether this is a manual isolator only.

 

[davesparks]

It’s a care home. The board is not readily accessible, but not impossible to get to by any of the staff. Please see a close up of main switch - I’d love to determine whether this is a manual isolator only.

That's a switch with a nominal current rating of 400A.

 

[westward10]

The only way that will go from ON to OFF is if someone physically does it.

 

[pc1966]

Is it for old folks with onset dementia, etc?

Just wondering if someone with fading electrical experience who thought they were on some job, etc.