In a couple of instances here in NZ I have had Inspectors who require extra plastic shrouding over metering CT busbars, even when the busbars are in a completely sealed chamber with metal fixed covers which require two tools to remove, engraved warning labels and are sealed with the power authority seal which only authorised persons are allowed to break. Add to this the fact that the Main Switchboard should be in a locked room and this requirement for additional plastic shrouding just seems frivolous.
The 1% of inspectors who raise this requirement always cite Reg 94, which states "all practicable steps must be taken to prevent accidental contact with live parts through the use of barriers and screens etc". It seems that the whole matter hinges on the interpretation of the word "practicable".
In all cases the Inspector will require that an extra plastic cover-plate be fitted under the metal fixed cover. This plastic cover-plate will take 15 seconds to remove for anyone with the same tools used to remove the metal fixed cover.
The only reason anyone needs to access a CT chamber is for CT maintenance when the meter stops running and in this case the main switch has to be switched off.
I am not ragging individual inspectors here, and in no way do I think my opinion is final. I would like to hear other members thoughts on this matter, especially from Australasia and the UK.
