240v consumer unit earthing
- Thread starter Stuupid
- Start date
-
- Tags
- 240v earth points ehu
To be fair, you would think @travelvolts instructions would be correct and comply to current regs etc
Just to ask a quick question regarding earth points.
i have installed my CU at the rear quarter in the cupboard, I’ve earthed it to the the body earth point near the rear light. is this ok?
i have installed my CU at the rear quarter in the cupboard, I’ve earthed it to the the body earth point near the rear light. is this ok?
By all accounts the factory earth points are pretty good.
P
Phil_G
Guest
You need a good clean connection thats all, it doesnt need to be heavy duty, its not carrying amps like your battery earth is. The RCD will trip at 30mA 
just a follow up on RCDs plus i googled it
The RCD wont notice a earth Break or if no earth is available as they dont use or are connected to Earth
What happens when an RCD is used without an earth connection? ... The RCD continuously monitors the Live (Active) and Return (Neutral) wires to see they are in balance, that is, inflow = outflow. Since the Earth is not part of this sensing, technically the RCD can protect without an Earth...Meaning operate correctly not protect a livened up van it wont know
SO MAYBE TEST YOUR CONNECTION FIRST ON ARRIVAL or just trust it's there or your lead / plug is tight in tip top condition ... Here's a link to Socket Testers after you plug into the site E H U just do a quick test in your 240 v socket simple plug & tell will tell you straight away that there's a earth connection and wires are all the right way round and in doors if you replace a socket tells you power is available before you check the fuse
cheap socket testers Socket Testers | Safety Always Comes First
The RCD wont notice a earth Break or if no earth is available as they dont use or are connected to Earth
What happens when an RCD is used without an earth connection? ... The RCD continuously monitors the Live (Active) and Return (Neutral) wires to see they are in balance, that is, inflow = outflow. Since the Earth is not part of this sensing, technically the RCD can protect without an Earth...Meaning operate correctly not protect a livened up van it wont know
SO MAYBE TEST YOUR CONNECTION FIRST ON ARRIVAL or just trust it's there or your lead / plug is tight in tip top condition ... Here's a link to Socket Testers after you plug into the site E H U just do a quick test in your 240 v socket simple plug & tell will tell you straight away that there's a earth connection and wires are all the right way round and in doors if you replace a socket tells you power is available before you check the fuse
cheap socket testers Socket Testers | Safety Always Comes First
There's differant sizes / speeds of RCDs tripping you still need a good sized wire = CPC circuit protection conductor to take a high surge on the initial fault and blow any fuses the fuses are to protect the cables / installation that is all.You need a good clean connection thats all, it doesnt need to be heavy duty, its not carrying amps like your battery earth is. The RCD will trip at 30mA
That depends on the total load with all equipment operated and length of cable run.
Cable Size Calculator - Cable sizing and selection | 12 Volt Planet
Cable Size Calculator - Read our guide to selecting cable of the correct type and size for your automotive, marine or leisure wiring application. Auto and Marine Electrical Components from 12 Volt Planet
www.12voltplanet.co.uk
I used a piece of earth wire from the arctic flex. 2.5mm
Cheers @Deaky - that makes sense as it’s multi-strand (flexible) and would fit easily in the screw clamp terminals inside the CU.
For now, I’ll only be running a 15A battery charger and a couple of sockets when on EHU so I guess an earth cable, like you say, taken from Arctic flex would be sufficient..
For now, I’ll only be running a 15A battery charger and a couple of sockets when on EHU so I guess an earth cable, like you say, taken from Arctic flex would be sufficient..
2.5 is ok for 16 amp max and you have RCDs. but a RCD is not connected to the earth side
Would highly recommend you buy a cheap plug in mains socket tester ( about a tenner )
you really need to check the 240 supply / hook up has a good earth once your hooked up it takes seconds and confirms you have power at the socket. in the unlikely event you have a power to earth fault, your van could become live with out the earth connected . you ll be fine sat inside till you step out.
and you don't know who plugged what into the site socket over the years to make a loose connection wiggled in and out or on your wandering lead dropped in the mud and Vans don't get wired up with a ring main take care out there
Would highly recommend you buy a cheap plug in mains socket tester ( about a tenner )
you really need to check the 240 supply / hook up has a good earth once your hooked up it takes seconds and confirms you have power at the socket. in the unlikely event you have a power to earth fault, your van could become live with out the earth connected . you ll be fine sat inside till you step out.
and you don't know who plugged what into the site socket over the years to make a loose connection wiggled in and out or on your wandering lead dropped in the mud and Vans don't get wired up with a ring main take care out there
P
Phil_G
Guest
Ditto the plug-in tester - leave it in the van. Some UHU sites have been known to have miswired outlets.
Your van sits on rubber tyres, the only earth connection is via the EHU so its essential to check that its present.
Your van sits on rubber tyres, the only earth connection is via the EHU so its essential to check that its present.
Im installing a blue male 16a socket under the bonnet, artic cable then into consumer unit with a 2 pole rcd and 16a RCD.
The ground pin will be wired directly to a clean chassis ground with minimum of 2.5mm2 cable and onwards to the sockets within the van.
In the event of someone touching a live wire, or the chassis becoming live the RCD will trip due to the imbalance from live to earth. If a piece of equipment plugged in develops a fault then the 16a breaker will trip.
Im going to have a socket tester to confirm the polarity and acceptable ground.
Can't see any other way other than connecting the earth to the chassis.
Anyone done anything different?
The ground pin will be wired directly to a clean chassis ground with minimum of 2.5mm2 cable and onwards to the sockets within the van.
In the event of someone touching a live wire, or the chassis becoming live the RCD will trip due to the imbalance from live to earth. If a piece of equipment plugged in develops a fault then the 16a breaker will trip.
Im going to have a socket tester to confirm the polarity and acceptable ground.
Can't see any other way other than connecting the earth to the chassis.
Anyone done anything different?
Last edited:
Electric-ian
New Member
Just reading back on this thread, is the earth connection to the chassis not for bonding extraneous metal parts ? I don't think it's intended as an earth for your EHU. The site should be supplying you an earth via a rod ( TT system which will be tested regularly via an approved electrician. The 30mA RCD will note any imbalance between live conductors. A TT system has to have RCD protection as the resistance of the earth path can be unstable and not normally low enough to trip an MCB under short For an MCB to trip the loop impedance must be low enough as in accordance with BS7671. The MCB in a TT system is only there for overload protection as the it unlikely to trip in the event of a fault within 0.4 or 5 seconds hece the RCD. Noting that in accordance with amendment 2 that only Type A RCD'S can be used where DC voltage is present.
It also states the that the overload protection must isolate All live conductors, meaning double pole MCBS.
It also states the that the overload protection must isolate All live conductors, meaning double pole MCBS.
So are you saying that the EHU earth should be isolated from the van body?
Electric-ian
New Member
No, the regs say an earth should be ran from the body back to the MET.
MET?
