Speak EV - Electric Car Forums banner
1 - 11 of 11 Posts

·
Registered
Joined
·
22 Posts
Discussion Starter · #1 ·
I'm in the process of contacting EV Charger installers and all of them are asking for pictures of the meter and main cut out fuse and its rating. However, I can't seem to see it because it is sealed inside a black box. See the attached picture. How do I find out what the fuse rating is as this black box is sealed and I believe it is illegal to cut the seal on this. I think the wiring for this house was done in the late 80s or early 90s but everything I read or pictures I see online seem to clearly show the fuse and its rating next to the meter. Has anyone come across this black box or something similar before and know what to do in this situation?

Any advice would be much appreciated!
 

Attachments

·
Registered
Joined
·
1,526 Posts
I thought most people realised that a picture of the main fuse is a complete waste of space ! Some (but by no means all) have a rating on outside - but that's just the rating of the fuse holder ; it's quite common for a 100A holder to have a 60A or 80A inside. You should however be able to ask your DNO what size fuse is currently fitted - and whilst talking to them ask about having it uprated (often a free service if you ask nicely).
 

·
Registered
Joined
·
331 Posts
Call the DNO and ask them what you’ve got, if they haven’t got the record ask them to come out and check and upgrade if necessary.
 

·
Registered
Joined
·
33 Posts
It took the DNO about two weeks to come and check mine, it was straight forward and free of charge. You can find out online who your DNO is, and find the contact details, mine took less than five minutes to sort, and similar time to actually check it.
 

·
Registered
Joined
·
22 Posts
Discussion Starter · #5 ·
I thought most people realised that a picture of the main fuse is a complete waste of space ! Some (but by no means all) have a rating on outside - but that's just the rating of the fuse holder ; it's quite common for a 100A holder to have a 60A or 80A inside. You should however be able to ask your DNO what size fuse is currently fitted - and whilst talking to them ask about having it uprated (often a free service if you ask nicely).
I see - I wasn't aware that the rating on the outside was just that of the holder. So sounds like it always needs to be checked. I'll contact the DNO. Thanks!

Call the DNO and ask them what you’ve got, if they haven’t got the record ask them to come out and check and upgrade if necessary.
Thanks for the suggestion. Hopefully they have a record or can come out quickly.

It took the DNO about two weeks to come and check mine, it was straight forward and free of charge. You can find out online who your DNO is, and find the contact details, mine took less than five minutes to sort, and similar time to actually check it.
Thanks. I'll get in touch with them and can hopefully get this done quickly.
 

·
Registered
Joined
·
523 Posts
Does anybody know why the holder cover does not have a hole or slot in it so the fuse rating can be easily seen?
 

·
Registered
Joined
·
179 Posts
The reason why the fuse is held behind a thick bakelite or plastic cover is to prevent molten hot metal spewing from it in the event the fuse failed under a direct short circuit and to prevent someone poking something metal in the hole to then potentially make contact with the metal parts of the fuse barrel / holder.
The DNO are pretty good about telling you the rating of the service head cutout. Either they'll have it on record, or they will come out (for free most of the time) to pop the cover and check.
 

·
Registered
Joined
·
179 Posts
Might be technically possible, but even today, one of the biggest provider of Service Heads, Lucy Electric, don't seem to offer it to DNOs and given the millions of households out there with ancient Bakelite things, there's no incentive for DNOs to change anything. My supply cable is a lead sheathed and bitumen covered affair and the BICC head must be from the 1950s or 60s by the looks of it! I think part of the logic against transparent viewing windows is to discourage the little scroats of this world from damaging the transparent window who might then try to syphon off power illegally to keep their illegal horticultural operations running!
 

·
Registered
Joined
·
1,371 Posts
Perhaps transparent?
You would need to find a transparent cover with the same properties as the current cover. Not bakelite any more, but I assume the newer cover material still has very good insulation / thermal / mechanical properties in the event of a catastrophic failure of the DNO fuse.
 

·
Registered
Joined
·
6,075 Posts
Might be technically possible, but even today, one of the biggest provider of Service Heads, Lucy Electric, don't seem to offer it to DNOs and given the millions of households out there with ancient Bakelite things, there's no incentive for DNOs to change anything. My supply cable is a lead sheathed and bitumen covered affair and the BICC head must be from the 1950s or 60s by the looks of it! I think part of the logic against transparent viewing windows is to discourage the little scroats of this world from damaging the transparent window who might then try to syphon off power illegally to keep their illegal horticultural operations running!
I think all of those old cutouts were designed in a bygone era pre attic horticultural endeavours😁

On a more serious note, the design of the Fuse Holder section was never about "user" information or convenience. Let's face it, if it wasn't for EV charging who would ever even think about the cutout.
 
1 - 11 of 11 Posts
Top