Electric tripping

Hi all, I have a 6kva supply and it regular trips at 26 amps, is this a bit on the low side?

as I understand it I should be able to pull around 30 amps.

I cannot have the water heater (10 amps) and the dishwasher on without it tripping,

same goes with the dishwasher and the kettle. If I put these two on at the same time it trips when the kettle switches off. The only other use is the t.v. And freezer.

advice please.

Hi Anthony,

I had same issue. I had 26 Amps with the two oven in parallel and it tripped, even with nothing on at the same time. My trusty electrician advised to call EDF and upgrade at 9kva (more expensive) as I could not and did not want to change the double oven. It solved the issue. No other way I am afraid.


Hi Anthony.

You haven't mentioned in your query whether your installation is tri-phase or mono-phase. If it is an older system, then it is probably tri-phase, and if you have all the load on just one or two phases, then it will tend to trip out sooner as regards the total load being applied. If it is a tri-phase system, then you need to ensure that the load on the 3 different phases is as balanced as possible.

Whilst the solution proposed by Christian will probably work, you should have the system checked for phase balance first in the interests of safety, as routing the total load through just one phase can be dangerous due to overheating of the wiring.

Unlike in the UK, the EDF are only responsible for the safety of the system as far as the Meter, so just because they increase the overall total supply, it does NOT mean that it is safe to do this on your particular installation.

Probably best to have a qualified electrician look at the system. Due to the way that us Brits tend to use our electricity, it is often best to have an old tri-phase system converted to mono-phase. This may require some rewiring, or can be achieved by reconnecting the existing wires in a different way, or a combination of both.

Additionally, you should also have the earth connection checked, especially before increasing the total maximum available power. Particular attention must be paid to the gauge (thickness) of the earth cabling, as it MUST be capable of carrying all of the total current available in the event of a major short circuit.

Also a very good thing to check that the correct differential circuit breakers are fitted to protect the entire system. These are also known as Residual Current Devices (RCD) and Residual Current Circuit Breakers (RCCB). These devices monitor the balance of the current between the phase (live) and return (neutral) wires of the circuitry, and automatically cut the current in the event of the slightest leak. This prevents the possibility of electrocution or electrical fires. There are two slightly different types ---- one for water connected appliances such as the water heater, dishwasher, washing machine circuits, and the other type for the remainder of the circuits. Following this link will give you pictures of many different makes of differential circuit breakers which will give you an idea of what you are looking for on the main switchboard -- https://www.google.com/search?q=differential+circuit+breaker&hl=en-GB&rlz=1T4PRFF_en-GBFR553FR553&tbm=isch&imgil=nlpmQ9cmLIoCtM%253A%253BIA3MdIVe_3uXXM%253Bhttp%25253A%25252F%25252Fwww.theinternetelectricalstore.com%25252Fkanlux-kr6-250032-black-switched-grey-cased-differential-current-circuit-breaker-25-amp-4242-p.asp&source=iu&pf=m&fir=nlpmQ9cmLIoCtM%253A%252CIA3MdIVe_3uXXM%252C_&usg=__kxsYUReu3tLu0378vca6dWOTsT8%3D&biw=1093&bih=513&ved=0ahUKEwjWjpPk3v3LAhXI3iwKHXZ0CY0QyjcIQg&ei=TfUGV5a0Gsi9swH26KXoCA#imgrc=nlpmQ9cmLIoCtM%3A

What they all have in common is a 'test' button. If your installation is not equipped with these, then I strongly urge you to have them fitted as soon as possible.

Hope this helps. Robert.

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Hi Robert, thank you for your most informative reply, this is a single phase system recently inspected by a French registered electrician. There is a Baco 1 phase 500ma

30 trip fitted on the incoming circuit just before the meter. On the meter which has pleine and creuse day and night tarrif blue. Setting 3 reads 30A-06kwh.

setting 5 reads 26a. I have used the test button to check it turns off.

on the fuse board there is a rcd fitted rated at 40a I have also used the test button on this to check it is working.

Hi Anthony,

In which case it is probably best to get the EDF fellow to come and check what the meter is currently actually capable of delivering, as opposed to what it says it is set to. Good idea perhaps to check your bill first to confirm what max power you are actually paying for. It's not unknown for meters to give trouble, especiqally if they have a bit of age to them.

A 30 amp setting (or 6KwA as the French express it) should allow you to draw about 6.5 to 6.7 Kw depending on the voltage fluctuation in the mains at the given time. Usually there is a bit of leeway in the setting on the plus side. (My own 60 amp rated supply has previously had 64 amps drawn through it without any problem.) The most modern meters have a reading which shows the maximum power that has been drawn through it at any time since installation, so perhaps this will assist in your investigations.

Good Luck, Robert.

Many thanks once again, I will get EDF to check the meter.

Good evening all, Please correct me if I am missing the point of the original query. However, if you have a 6000 watt (6kva) power supply and the supply voltage is 240 volts then the maximum current you have available is 25 amps. Ergo, if your fuse is blowing at 26 amps, that is correct. If you have a requirement to draw in excess of 25 amps you will need to increase your supply from 6kva to 9kva, which would give you a combined availability of 37.5 amps. For reference, watts divided by volts equals amps (6000 / 240 = 25)

Query solved with this info! Many thanks

just to add to this the official voltage is 230 +- 10% so between 207 and 253 and is normally around 220v, this will of course alter your available amps from the 240 figures quoted above

Whilst I agree that 240 volts is both the usual and actual norm in the UK, my experience here in Vendee (western France) is that the actual voltage is normally in the range of 220 to 223 volts. Although this does not seem a huge difference at first sight, it does make a fair bit of difference when the math is done in the process of calculating either wattage or ampage.

To clarify, the example given was based on 240v as it made the maths simpler with whole numbers, and I did say 'if'. Therefore 6kva(6000w) @ 230v would be 26.086A

For many years, mainland Western Europe has used a mains electricity supply rated at nominally 220VAC 50Hz. The UK used 240VAC 50Hz.

Currently (pardon the pun), ALL Western European supplies are classified 230VAC. In reality there is no 230VAC supply unless you create one locally. 230VAC was a “standard” created during European "harmonisation" to give a single voltage standard across Western Europe, including UK and Irish Republic.

Although the ideal would have been to have a single voltage there were too many political, financial and technical obstacles to reduce UK voltage to European levels or to increase European voltage to UK levels, so a new standard was created to cover both. This was achieved by changing the tolerances of previously existing supply standards. UK voltage to 240VAC + 6% and - 10% and European to 220VAC +10% and -6% (thereby creating a manageable overlap) and we would call these two combined 230VAC, despite the fact that nobody was intentionally generating at 230VAC!