BG Consumer Units - live parts accessible without tool

[OwainDIYer]

I have purchased a BG consumer unit.

It has 'quarter turn' fasteners for the front cover.

By pressing my finger on them and turning, I can undo them and remove the front cover without the use of a tool.

The busbar shield further just pushes on so can be pulled off, again without use of a tool.

Compliant?

 

[securespark]

Tongue in cheek, but could your finger be regarded as a tool?

 

[Taylortwocities]

Methinks you protest too much

 

[PrenticeBoyofDerry]

I have fitted a few BG CUs, can't say if I have ever been able to turn the cover fitting screws by finger, in fact I have found them to be quite a stubborn bugger at times!

 

[ericmark]

Unless there is some locking device to stop vibration undoing screws most screws can be tightened and slackened by hand until the torque is applied by a tool and unless you were to torque up the screws to recommended torque then one could not say if the screws could or could not be undone by hand.

Most people do not do up every screw with a torque wrench but if you want to be pedantic about undoing screws by hand then one also must be pedantic in tightening them with a torque wrench.

I have come across consumer units where one can remove the blanks without a tool and have questioned if correct blanks have been fitted. Some makes the blanks need turning and can only be fitted when the cover is off. Others simply push into place. However some distribution units have a slide so you can isolate the MCB and using these slides the tags to connect the MCB to are dead. So removing a blank would not expose a live part.

Unlike distribution units all consumer units are type tested and it would be hard for any unit to be marketed which did not comply. Only by using non type tested items within the unit could there really be a problem. This is why you can only fit MCB's and RCBO's of the same manufacturer as the consumer unit to comply. Again being pedantic but whole question is pedantic in first place.

 

[ericmark]

Tongue in cheek, but could your finger be regarded as a tool?

Only if used by another person. Cutting the finger off some ones hand and then using the finger to gain access i.e. finger print recognition then that finger would be considered as a tool.

 

[mfarrow]

Eric, I don't think I've seen any quarter turn screws which can be torqued up.

 

[ban-all-sheds]

Or any which can't be turned with just a finger or thumb.

 

[OwainDIYer]

Unlike distribution units all consumer units are type tested and it would be hard for any unit to be marketed which did not comply. .... Again being pedantic but whole question is pedantic in first place.

I don't think the question is pedantic. Unlike a lampholder or ceiling rose, which are AFAIK the only accessories where access to live parts without a tool is permissible, or any other accessories which do require use of a tool, a consumer unit has a busbar with no MCB or RCD protection and if the incoming tails are poorly terminated then there is permanently live copper even when the main switch is off.

Also consumer units are often mounted at low level near an underground incomer.

Therefore I was rather surprised at a new CU being openable without a tool.

An existing Proteus switchfuse has similar quarter-turn fasteners but they're very deeply recessed so a screwdriver is required. The BG ones fasteners are flush with the front face.

 

[JohnW2]

I don't think the question is pedantic. Unlike a lampholder or ceiling rose, which are AFAIK the only accessories where access to live parts without a tool is permissible, or any other accessories which do require use of a tool, a consumer unit has a busbar with no MCB or RCD protection and if the incoming tails are poorly terminated then there is permanently live copper even when the main switch is off. ...Therefore I was rather surprised at a new CU being openable without a tool.

I don't think that BG CUs are unique in this respect.

As eric has said, if it had been deemed that the design of a CU was such that it could be opened without use of a tool, then it presumably would have failed 'type testing'. Furthermore, as others have said or implied, these quarter-turn fasteners are often a devil of a job to turn (without damaging them), even with a tool. I wonder, therefore, whether you have considered the possibility that the design is fine (can't be opened without use of a tool) but that the example you have seen has faulty fasteners which can be opened just with a finger/thumb?

Kind Regards, John

 

[OwainDIYer]

[
As eric has said, if it had been deemed that the design of a CU was such that it could be opened without use of a tool, then it presumably would have failed 'type testing'. Furthermore, as others have said or implied, these quarter-turn fasteners are often a devil of a job to turn (without damaging them), even with a tool. I wonder, therefore, whether you have considered the possibility that the design is fine (can't be opened without use of a tool) but that the example you have seen has faulty fasteners which can be opened just with a finger/thumb?

I have considered that possibility and am emailing BG to clarify and just in case there's a batch defect.

 

[JohnW2]

I have considered that possibility and am emailing BG to clarify and just in case there's a batch defect.

Sounds like a good idea, and presumably stands a fair chance of their response indicating that it is not meant to be possible (per the design) to open them without a 'tool'.

The 'without a tool' criterion is, of course, far from foolproof, since the very people we are most concerned about (children) are also notorious for playing around with 'improvised tools' of one sort or another!

Kind Regards, John