Panel/Switchgear Yellow Electricity Warning Labels

AJJewsbury:

So in this example the label would at least state 400V as this is the nominal voltage value for Uo however as BS7671 514.10.1 requires that the maximum voltage be stated then this voltage warning label may be required to state all the way up to 440 (690V phase/phase +10%) 759V if indeed that is the maximum voltage at that junction box.

Humm tricky. If you look at chapter 44 you could decide that the maximum voltage present could be a lot higher again (if you were to take account of all sorts of LV and HV fault conditions - let alone switching or lightning spikes). But that's getting silly (IMO), so my personal interpretation is that they're only asking for a maximum within the context of nominal voltages. It also specifies that the warning should be of 'the maximum voltage to earth present is clearly visible' (my emphasis) - so if it's 690V L-L I think I'd expect a 400V label in that context (690/√3) .

 

   - Andy.

Andy,


Ok yes phase to earth. It would really clarify things if BS7671 514.10.1 used the term nominal instead of maximum. As maximum voltage for the example circuit could be (690/√3) + 10% as per BS EN 60038. I am going to dig a bit further an see if I can find something definitive. Seems a bit odd that there are so many companies selling 230V yellow warning labels if BS7671 does not require them to be installed, maybe they are required under the standards referenced by gkenyon but I have not been able to find an evidence for this in BS 61439-1, BS 61439-2, BS 61439-3, BS 61439-6 thus far.

AJJewsbury:

So in this example the label would at least state 400V as this is the nominal voltage value for Uo however as BS7671 514.10.1 requires that the maximum voltage be stated then this voltage warning label may be required to state all the way up to 440 (690V phase/phase +10%) 759V if indeed that is the maximum voltage at that junction box.

Humm tricky. If you look at chapter 44 you could decide that the maximum voltage present could be a lot higher again (if you were to take account of all sorts of LV and HV fault conditions - let alone switching or lightning spikes). But that's getting silly (IMO), so my personal interpretation is that they're only asking for a maximum within the context of nominal voltages. It also specifies that the warning should be of 'the maximum voltage to earth present is clearly visible' (my emphasis) - so if it's 690V L-L I think I'd expect a 400V label in that context (690/√3) .

 

   - Andy.

Andy,


Ok yes phase to earth. It would really clarify things if BS7671 514.10.1 used the term nominal instead of maximum. As maximum voltage for the example circuit could be (690/√3) + 10% as per BS EN 60038. I am going to dig a bit further an see if I can find something definitive. Seems a bit odd that there are so many companies selling 230V yellow warning labels if BS7671 does not require them to be installed, maybe they are required under the standards referenced by gkenyon but I have not been able to find an evidence for this in BS 61439-1, BS 61439-2, BS 61439-3, BS 61439-6 thus far.