RCBO socket circuit tripping.

[GBDamo]

I'm stuck here fellas.

I have a radial with only one double socket outlet in 2.5mm T&E on a 20A RCBO running five meters in surface mounted trunking. TN-S, R1 and R2 good, 243V measured, Ze 0.12, Zdb 0.29, Zs 0.36, IR all +200MOhms.

RCD trip tests all ok at 0 and 180 and ramp 24mA.

Now these sockets are only used for one thing, two 580W water distillers.

Both have been clamped during operation and are drawing 2.4-2.6A as expected.

Both have been IR tested L-E & N-E and +200MOhms.

I am stumped to the point where I may run in a new socket on a new RCBO, cost not an issue the customer just wants it stopped.

My concern is the issue could be with one or both the distillers units and not the circuit.

I don't have a low current clamp meter so cannot measure earth leakage directly.

Any ideas where to look next, I'm still on the job by the way.

 

[PEG]

Hi,do you know if any internal switching,is conducive to the correct operation of an RCD?
Machines may be working correctly,but internal control devices could cause the RCD to sense a "fault",and trip.

 

[static zap]

Is all water collected ,or is the area steaming up in the cold of night. (more ventilation?)
..Like sound of a timer so distillers are not put through overheat trip cycle...
Divide and conquer ,run one independently!

 

[Charlie_]

With various types of steam generating equipment the manufacturers recommend no RCD type protection.
Especially as the equipment starts to age..
Without any technical information in the ‘proper’ language hard to diagnose.
With similar equipment the water reservoir/heating chamber will use a method of water level detection

 

[GBDamo]

So - a “plug in” appliance that has degraded over time and likely has 20mA or more earth leakage is to be kept in service by adapting the electrical installation to remove the RCD ?
Just checking I’ve understood this correctly .

No you

So - a “plug in” appliance that has degraded over time and likely has 20mA or more earth leakage is to be kept in service by adapting the electrical installation to remove the RCD ?
Just checking I’ve understood this correctly .

no, reread what has been suggested.

Find a manual and see if this is enlightening.

Contact the manufacturers and see if these machines cause RCD problems.

If it's a known idiosyncracy, adapt circuit.

If it's a genuine fault, ascertain which machine it is and remove from service, repair or replace.

 

[marconi]

Could you say a little more about the RFC and 'random mic socket' (See #27)? How are they fed in the CU ? By mic do you mean MICC?

I think I would test out these final circuits out too and the gas/water bonding.

 

[marconi]

And does the RCBO have a functional earth connection?

I'd be interested to know what voltage you measure between N and E at the CU.

Is it definitely TNS?

 

[MJPD29]

If you have eliminated everything else and also tested the rcbo then it has to be the distillers surely

 

[marconi]

Re:#37 I was musing on what/where else might the fault be if the two distillers are actually not faulty and as you say all tests so far indicate the new radial and its RCBO are satisfactory.

 

[GBDamo]

Could you say a little more about the RFC and 'random mic socket' (See #27)? How are they fed in the CU ? By mic do you mean MICC?

I think I would test out these final circuits out too and the gas/water bonding.

Is the probability these questions will lead to a solution greater than 1000:1.

At the moment I'm after low hanging fruit.

I do respect your knowledge but in reality how likely the gas/water bonding is going to be the cause of this fault?

 

[GBDamo]

Forgot to add, been informed they will be disposing of these units in favour of a reverse osmosis unit to generate purified water.

Rather embarrassing I installed the services for the RO unit two weeks ago so should have known they were shortly to bin the distillers. In my defense this was three floors away in a different part of the building but the same site.

 

[static zap]

...... been informed they will be disposing of these units in favour of a reverse osmosis unit ......

That's life , now energy will be saved ,but more water wasted ?
Which will the greens worry about 1st.

 

[PEG]

Hi,do you know if any internal switching,is conducive to the correct operation of an RCD?
Machines may be working correctly,but internal control devices could cause the RCD to sense a "fault",and trip.

That's life , now energy will be saved ,but more water wasted ?
Which will the greens worry about 1st.

....Don't worry,they always find something

....It never seems to be the way they get to their meetings,here or abroad,or what is at the end of where they charge their phones
(Never met a green activist yet,who does not possess a mobile...)