gkenyon:

Mike M:

The conclusion that we had arrived at was that was with nominal voltage being defined as voltage by which or part of an installation is designated we would have to say that the equipotential bonding cables do not form part of a system that has a designated voltage and therefore are not ELV or LV

I don't agree with your conclusion under all circumstances.


If the cable is correctly connected at BOTH ends then it can definitely be classed as having Earth potential, and there's not always a need to even insulate it. Protective conductors do not always require insulation.


HOWEVER, if one end is disconnected for whatever reason, then a hazardous condition may be prevalent.


So, as I have previously intimated, it depends why you are asking the question. There are two cases in particular which must be highlighted:

1. For electrical and electronic system maintenance activities, protective conductors and functional earthing conductors may have to be treated like live LV conductors when they are disconnected at one end.

• Also common is the case where a screen, armour, etc., is connected to one earthing system at one end, and the other end is presented at part of an installation with a different earthing system. Again, we need to treat that protective conductor or functional earthing/bonding conductor in the case of a screen, at the very least in the same manner as a live conductor - gapping and insulating against contact.

I apologise for having to restate this point, but it's very important if someone is reading this thread because they are assessing risks for certain work activities.

 

gkenyon:

Mike M:

The conclusion that we had arrived at was that was with nominal voltage being defined as voltage by which or part of an installation is designated we would have to say that the equipotential bonding cables do not form part of a system that has a designated voltage and therefore are not ELV or LV

I don't agree with your conclusion under all circumstances.


If the cable is correctly connected at BOTH ends then it can definitely be classed as having Earth potential, and there's not always a need to even insulate it. Protective conductors do not always require insulation.


HOWEVER, if one end is disconnected for whatever reason, then a hazardous condition may be prevalent.


So, as I have previously intimated, it depends why you are asking the question. There are two cases in particular which must be highlighted:

1. For electrical and electronic system maintenance activities, protective conductors and functional earthing conductors may have to be treated like live LV conductors when they are disconnected at one end.

• Also common is the case where a screen, armour, etc., is connected to one earthing system at one end, and the other end is presented at part of an installation with a different earthing system. Again, we need to treat that protective conductor or functional earthing/bonding conductor in the case of a screen, at the very least in the same manner as a live conductor - gapping and insulating against contact.

I apologise for having to restate this point, but it's very important if someone is reading this thread because they are assessing risks for certain work activities.