Earthing of exposed metal parts

[Kensprint]

I am a new member an have what I think is an interesting question.I have been given a spec for an product which will be installed outdoors and be accessed by the public. The installation requires the fitment of 4x heater lamps. The lamps are connected to 230v ac by means of a plastic junction box to which 4x sockets are secured by 8 x M3 metal screws. There are also 4xM8 bolts securing a bracket to the box. The bracket is held onto a powder coated aluminium spar by compression, thus there is no earthing of the part. As Far as I am concerned all of the exposed metal parts should be earthed. Am I correct? If so and as it is a manufactured product. What are the correct regulations which should have been followed in manufacture.

I look forward to your thoughts

 

[wayne]

a drawing would help
so we are talking about 4 heaters plugging into an adaptable box which is fixed onto structual metal
as this is a circuit outdoors supplying sockets it would be on an rcd and 0.4 seconds

if the metal work is'nt part of the installation then its extraneous
in the 16th reg 413-02-02 requires exposed metallic structural parts to be have an equipotential bond same as gas/ water /air con.......
table 54h gives csa of equi bond conductors
hope this helps and im not off track completly

 

[Shakey]

It wuld be helpfull to know more about it

When you say 'installed' does it come with a lead already attatched? And if not does it have a connector block? Look at the connector block and see if its got an earth terminal

Also the manufacturer should state if its Class 1 or Class 2. If its class 2 it will have the double insulated symbol (square within a square) if it doesnt have this its class one andshould be earthed

 

[Kensprint]

The plastc junction box is on a lead which runs down the column of the item. This lead should be connected at within a sleeve to the mains supply from the premises. Inside the junction box there is 32A Chocolate block connectors. Phase, neutral and earth are connected into this connector block and from it to the heater sockets. No attempt has been made to earth the various screws and bolts which are located inside the junction box and pass through it to be exposed outwith it. The connector block is not secured within the box. My concern is that if the phase wire became detached from the connector block or from one of the heater sockets it could easily make contact with one of the screws or bolts rendering them live and a danger to any member of the public who touched them inadvertently.

My past experience is in the manufacture of laboratory instruments. Any eposed metal part be it casework, protruding screws etc needed to be earthed.

Sorry I have no picture