Curious they would put an indicator on the 'commercial' version only, and that the spec. is otherwise identical!
Could it be the fact there often fitted sideways, i believe there is certain rules regarding them indicating whether there on/off
Hager RCBOs - difference?
- Thread starter phatboy
- Start date
Could it be the fact there often fitted sideways, i believe there is certain rules regarding them indicating whether there on/off
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Thanks. That's what I've always thought, as described by me a couple of posts back.
However, whilst using 'mixed' (hence not 'type-tested') devices in a CU/DB may be a "very bad idea" in terms of regulations, do you really believe that, in reality, it makes any difference to breaking capacity? In any event ...
Is there any logical (as opposed to regulatory) reason why that cannot be used to justify a DB containing 'mixed' 6kA devices in a domestic installation?
The reality surely is that PFC >6 kA in any part of a domestic installation is virtually never seen/possible? Even if the fault were actually 'in' the CU/DB, that would only allow about 14m of 16mm² cables (which is what supplies my installation) or 22m of 25mm² cables between CU/DB and the substation transformer, and those lengths would probably not even get from CU/DB to the boundaries of my property.
Kind Regards, John
That would certainly make sense, but I can't say I've ever seen any indication that ones which do not have an on/off indication should not be fitted 'sideways' (in order to satisfy a 'rule' such as you suggest), have you?
Kind Regards, John
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No - but by mixing devices, the installer becomes the designer of the assembly, and is therefore responsible for any problems that may occur from it's use.
If full design calculations and other specifications were made available and the decision to use a variety of different devices could be justified, then there would be no problem.
That would need to include an analysis of the thermal, electrical, and electromagnetic characteristics of the devices both individually and when combined within the assembly.
Since no one is likely to want to do any of that, sensible people install the devices provided by the manufacturer.
Others may just fling in any old rubbish and hope they are not identified when the building burns down.
In larger installations, the two or more protective devices are not contained within the same assembly, which makes the design of the installation vastly simpler.
This all sounds very 'hypothetical' to me.
Don't forget that (at least at present) we are talking only about the breaking capacity of devices. If it can be demonstrated that, without major changes to the distribution network (in some cases, like mine, quite possibly requiring the installation of a substation in one's garden!) the PFC could not possibly ever be anything like as high as 6 kA, do you really believe that any combination of devices (each rated at 6 kA) could possibly fail to have adequate breaking capacity?
I suppose that, even in a domestic installation, one could put each and every protective device in a separate enclosure, but that would be plain silly, and would seemingly achieve nothing particularly useful!
Kind Regards, John
What I was getting at was maybe Hager decided the window was a better option on there brand, rather than a necessity, whereas others opted for an alternative means of on/off indication, to satisfy the standard there made to.
If that makes sense
I’m sure on rcds there is a purpose to them.
They don’t indicate the same as the lever.
They flag up red if a fault has caused a trip but stay white if manually switched off.
Something like that.
They don’t indicate the same as the lever.
They flag up red if a fault has caused a trip but stay white if manually switched off.
Something like that.
There is also the difference that a different two of the three RCBOs have a '3' under the kA rating - and a colon in the name/logo.
The Hagar logo is different.
And a blue square by the test button
And a blue square by the test button
I remember hearing somewhere that they are "guaranteed" to break the rated current, and possibly more, but not more than once (i.e. they may be destroyed while carrying out their duty)
That makes sense, but the greater problem is when they are not visibly damaged or destroyed, but perhaps no longer able to do quite what it says on their tin - yet essentially untestable. I certainly don't think I would be very comfortable relying on a device after I knew or suspected that it had broken a current anywhere near its 'rating'.
However, I would think that a PFC anywhere near even 6 kA (let alone 16 kA) would be almost unknown in a domestic installation, so that issue is probably rather moot in relation to such installations.
In any event, returning to my comment which you quoted, can you actually think of any mechanism whereby having a 'mix of makes' of devices in a DSB/CU could possibly have any significant effect on the breaking capacity/capabilities of any one of them??
Kind Regards, John
Maybe ... but what "alternative means of on/off indication" did you have in mind?
Mind you, if Andy is right in his suggestion does not change colour if it is turned off manually, then it would be useless (arguably potentially dangerous) as an "on/off indication"!
Kind Regards, John
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The colour indicator must go to red or green to indicate the position of the contacts, regardless of the position of the lever.
Might he have been thinking of RCDs such as MEM, which break to an intermediate position, and have to be manually moved further "off" before they can be reset to "on?"
Might he have been thinking of RCDs such as MEM, which break to an intermediate position, and have to be manually moved further "off" before they can be reset to "on?"
As I implied, that's what I would have thought.
Who knows? - I can't read his mind
At least some MK (and I think some Wylex) RCDs operate as you describe, but that's nothing to do with the presence/absence of colour indicators.Kind Regards, John
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