Earth leakage tripping with no load ?

**Derlyn** · 17-Oct-20, 12:30 AM

Hi all

Just a little video as promised ( a man of my word ) made on 4th Feb 2020 showing that an earth leakage relay does not trip on a neutral earth fault without a load connected.

Please forgive the filming quality. I am an electrician and not a film maker.

https://www.youtube.com/watch?v=jxG3KFppbZc

Peace out .. Derek.

**skatingsparks** · 18-Oct-20, 01:13 PM

Er. And?

**Derlyn** · 18-Oct-20, 07:16 PM

Originally Posted by skatingsparks

Er. And?

I made this video in response to a number of active forum users who were / are under the impression that all earth leakage relays will trip on an earth to neutral fault even with no load connected. Not so.

Peace out .. Derek

**Frans400** · 18-Oct-20, 02:55 PM

Help me if I'm wrong guys but dis is not a problem because there will be no current on the neutral wire and when a second appliances(load) is connected it will cause the RCD to trip.

**Derlyn** · 18-Oct-20, 07:16 PM

Originally Posted by Frans400

Help me if I'm wrong guys but dis is not a problem because there will be no current on the neutral wire and when a second appliances(load) is connected it will cause the RCD to trip.

Exactly.

Peace out .. Derek

**ians** · 20-Oct-20, 09:06 AM

Chint is making arrangements to drop off a demo unit to test in my workshop ... lets see what happens.

**ians** · 21-Oct-20, 08:13 AM

" Only some of the suburbs, especially the older one's, where the service cables are overhead, no earth is supplied. Only 2 wires. Live and neutral.

My house, for instance, is in one of these older areas but being a newish house compared to the rest, has an underground service cable where a seperate earth is supplied.

My test video will be uploaded this coming weekend.

Peace out ... Derek"

I need to read all the posts

**ians** · 19-Oct-20, 08:04 AM

I am curious to figue out why my earth leakage unit trips when I perform a similar test ...but Dereks unit doesnt.

I need to figue how a 14 mA leakage current is displayed on the leakge current tester prior to it tripping without a load connected ... in fact both the test earth leakage and the unit in my sub DB trips shortly after the test bench unit trips ... i am going to bypass my Sub DB earth leakage unit

John Ward explains in in a really simple manner ... as i have mentioned ... I understand that a leakage current of around 20-30mA or an unbalance between the live and neutral is required to trip the unit ... but what i dont understand is why my unit trips on the work bench ... what is creating the 14 mA displayed on my leakage current tester ... if no load is connected (ideal situation).

in 99.9 % of the cases where the earth leakage has tripped when i touch the neutral ... the earht leakage has always been connected in a DB ... never a test bench situation ... when i carried out the test on my workbench I was hoping it wouldnt trip ... the only difference betwee nmy test and Derecks test ... I didnt use a plug and plug top ... i just touched a piece of wire between earth and neutral.

https://www.youtube.com/watch?v=JTku...annel=JohnWard

**Jaws** · 19-Oct-20, 11:44 AM

Originally Posted by ians

I am curious to figue out why my earth leakage unit trips when I perform a similar test ...but Dereks unit doesnt.

I need to figue how a 14 mA leakage current is displayed on the leakge current tester prior to it tripping without a load connected ... in fact both the test earth leakage and the unit in my sub DB trips shortly after the test bench unit trips ... i am going to bypass my Sub DB earth leakage unit

John Ward explains in in a really simple manner ... as i have mentioned ... I understand that a leakage current of around 20-30mA or an unbalance between the live and neutral is required to trip the unit ... but what i dont understand is why my unit trips on the work bench ... what is creating the 14 mA displayed on my leakage current tester ... if no load is connected (ideal situation).

in 99.9 % of the cases where the earth leakage has tripped when i touch the neutral ... the earht leakage has always been connected in a DB ... never a test bench situation ... when i carried out the test on my workbench I was hoping it wouldnt trip ... the only difference betwee nmy test and Derecks test ... I didnt use a plug and plug top ... i just touched a piece of wire between earth and neutral.

https://www.youtube.com/watch?v=JTku...annel=JohnWard

Hi Ian

I haven't looked at the video, but thinking about a possibility:

In an electrical circuit with a solid grounded neutral or star point the earth and neutral must be at the same potential. The voltage / potential difference between a live and neutral conductor must be exactly the same a the voltage measured between a live and ground conductor. And the voltage measured between neutral and earth should be 0 V.

But in practical circumstances this is not always the case. So if the voltage difference between Neatral and Earth is sufficient to allow the Earth Leakage to detect a current flow of its rated current it will trip when you connect the earth and neutral down stream of the Earth Leakage device without any current flowing in the live conductor / or have a load connected.

**Justloadit** · 19-Oct-20, 01:07 PM

Originally Posted by ians

I am curious to figue out why my earth leakage unit trips when I perform a similar test ...but Dereks unit doesnt.

I need to figue how a 14 mA leakage current is displayed on the leakge current tester prior to it tripping without a load connected ... in fact both the test earth leakage and the unit in my sub DB trips shortly after the test bench unit trips ... i am going to bypass my Sub DB earth leakage unit

John Ward explains in in a really simple manner ... as i have mentioned ... I understand that a leakage current of around 20-30mA or an unbalance between the live and neutral is required to trip the unit ... but what i dont understand is why my unit trips on the work bench ... what is creating the 14 mA displayed on my leakage current tester ... if no load is connected (ideal situation).

in 99.9 % of the cases where the earth leakage has tripped when i touch the neutral ... the earht leakage has always been connected in a DB ... never a test bench situation ... when i carried out the test on my workbench I was hoping it wouldnt trip ... the only difference betwee nmy test and Derecks test ... I didnt use a plug and plug top ... i just touched a piece of wire between earth and neutral.

I suspect that you have a potential difference between Neutral and Earth on your incoming side, which causes a current to flow from the Neutral to Earth through the ELU when you short them out. It sees this imbalance of current and trips.