Where did all this CPC thing come from. I have been in the trade far to long . To me and other people I know ,it’s a Earth wire and always will be . To confuse the issue even more if I buy a drum of cable from my wholesalers.It says on the label Twin and Earth . Not twin and CPC.. Even on electrical accessories it never talks about a CPC always Earth I don’t encourage DIY but at least most DIYers would at least understand the term Earth wire . Definitely not CPC . so we want to keep confused DIYers to a minimum. Then again a large percentage of electricians still call a consumer unit a fuse board. But that’s another story . In no way is this a criticism to this excellent video.
It’s called CPC now because there are certain systems where it’s not an earth Generally specialised hospital power systems or higher availability systems.
I don't understand why it's important to to torque the screws. 2.5 nm is very low. Terminals relax over time. We were always encouraged over tighten with our hands. I wonder if this has anything to do the 400 CU fires each year and the reason for CU units to be metal to help with the fires?
These are all soft metals - over-tightening is one of the things that'll lead to a joint relaxing (as the metal goes past the plastic deformation point and then provides no extra clamping load, but is now mechanically distorted and may not provide even clamping force). This is more of an issue with a cage clamp and the comparatively short tapped threads, plus a sheet metal clamp, compared to a screw in a brass bar which can handle comparatively high loads, although you can still certainly over-tighten and maybe even strip a brass screw or thread. As for using a torque screwdriver: it's consistency. Yes, torques are only good to around 25% tolerance on clamping force in real-world applications (hence TTT and TTY for critical mechanical applications) and yes, some of us develop pretty good "torque wrists" - but none of us has a calibration certificate, and the apprentice with three months' experience probably can't hit 2.5 +/- 1Nm reliably on all 40 screws to do a fairly simple wiring job. Is it that much of a big deal? 99.99% of the time, no. How long does it take an electrician to do up ten thousand screws and have one which *is* a problem? Probably about three months, or less if it's a big job. For the price of a 2.5 and a 5Nm, fixed torque driver, the cost savings associated with never having a "undertorqued or stripped screw" problem are well worth it.
If you over tighten you can crush the copper to the point where it's very thin and weak. This leads to breaks and arcing. Open enough consumer units and you will see it.
Great video, Where would you fit an inline meter in this setup? The customer wants to monitor the power usage coming into the cabin so they know exactly how much power the cabin is consuming separate from the main dwelling. The meter in question is same size as the RCD and just snaps onto the rail.
Festival in this case metres are not sold for this brand so type testing would not allow it to be installed inside this consumer unit but ones are available or an external electricity meter could simply be installed next to it
Just curious why you connect the incoming wires to the MCB first and from there into the RCCB. I believe in Germany you go into the RCCB first, then into the MCB and then on to your appliance. or does it not matter in the end, because the MCB will be triggered first anyway.
Why do we need to use a special slotted pozi screwdriver? I thought the point of pozi was for use with torque drivers alone vs normal cross head which can't be torqued?
Because it keeps screw head in better condition, especially in a college where they want to reuse this multiple kind is also the correct way and if you get a screwdriver kit come with some bits
Please i wanna ask a question outside of this video. According to the "On site guide" under cables ans their resistance. It states that 2.5mm² cable has a resistance of 7.41mOhms per metre. So i cut exactly 1m cable and use digital multimeter to measure the resistance and i had 0.00 ohm, but i had 0.50ohms when i used the clamp meter... Please why didn't i get the 7.41mOhms as stated... Or what's the right instrument to use. Thanks
Absolutely not there’s a class two size standard conductors not class five fine stranded conductors it is very unsafe is feral terminals are rated for them with this type of conductor
Problem with cheap imports like Fusebox, although popular these days, the attention to detail and safety is poor. Open cage devices like the ones used here can lead to misconnection of the busbar and overheating even fire conditions can occur. Also, the design of those mcb's means that to replace a device or upgrade a circuit you have to disconnect every connection to remove the busbar and then the device. Then of course you have to reconnect again and risk misconnecting the busbar into the device. I only fit Crabtree Starbreaker with the plug in devices. A far safer and quicker install and when you need to change a device you just clip out and refit without disturbing any other circuits.
Fuse boxes decent quality it’s fine because it needs to realistic expectation of budget versus safety compared to a real cheap no name one Crabtree star breaker has had several recalls in the past due to its past not being fixed for purpose so I personally would never trust it in this case if you cannot install the bus bar correctly it is install error not product safety
You should not be doing electrical work rating is very important because if you overdo it it can get it to terminal cause it’s a loose this rating is designed to be the best performing overtime if you will not follow it quite simply you should not be doing anything related to this
