Panel/Switchgear Yellow Electricity Warning Labels

AJJewsbury:

BS 7671 regulation 514.10.1 seems to be phrased all in terms of nominal voltages, so I would expect notices in compliance of that regulation at least to show nominal. Note that it's unusual to actually need such a notice from a BS 7671 point of view these days - since the requirement only applies where the voltage exceeds 230V nominal to earth - thus nothing is needed for either single phase 230V nominal systems (despite possibly up to 253V being present), or normal three-phase 230/400V systems despite the nominal 400V between lines.

  - Andy.

Andy,


Ok so for example:


> power supply to a motor


> 690Vac nominal voltage U 


> junction box installed next to the motor for the purposes of reducing the cable cross sectional area so that the supply cable fits into the motor 


As per BS 7671 regulation 514.10.1 the junction box would have to be fitted with a warning of the maximum voltage to earth.


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.


Do you agree ?

AJJewsbury:

BS 7671 regulation 514.10.1 seems to be phrased all in terms of nominal voltages, so I would expect notices in compliance of that regulation at least to show nominal. Note that it's unusual to actually need such a notice from a BS 7671 point of view these days - since the requirement only applies where the voltage exceeds 230V nominal to earth - thus nothing is needed for either single phase 230V nominal systems (despite possibly up to 253V being present), or normal three-phase 230/400V systems despite the nominal 400V between lines.

  - Andy.

Andy,


Ok so for example:


> power supply to a motor


> 690Vac nominal voltage U 


> junction box installed next to the motor for the purposes of reducing the cable cross sectional area so that the supply cable fits into the motor 


As per BS 7671 regulation 514.10.1 the junction box would have to be fitted with a warning of the maximum voltage to earth.


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.


Do you agree ?