SAFE-T-CUT TRIPPING DAILY

[sometimewoodworker]

4 minutes ago, livram said:

I have cheap tester and as soon as it gets to within 6 inches of any breaker wire it lights up. But it DOES NOT light up at any part of the neutral bar.

Sounds like a non contact tester like this and that sounds like your polarity is OK

Edited April 11, 2020 by sometimewoodworker

[sometimewoodworker]

One of these can be useful 

and yes for the OCD I did put it at an angle to the tiles just to mess with you ???? 

[Metropolitian]

Main breaker 63 amp. If that breaker is good (eg. not tripping on lower current than 65a) then the fault has to be looked somewhere else.

It is hard to tell which part get in action, the main breaker or the rcbo, as they are mechanically connected.

 

What now comes into my mind is that there IS an leak fault, even if there is no earthing in the CU.

If one of the outdoor unit is connected to earth (home harness, or wire into ground, or bonded to some roof iron) and a little leak is ok but many applicances it all counts and once above the 20mA (The OP said he has the dial on 20) then the rcbo would trip as the current in the N is not equal as L.

 

To the OP. Do measure the current in both lines,  Live and Neutral, each one.

 

 

 

[livram]

2 minutes ago, Metropolitian said:

Main breaker 63 amp. If that breaker is good (eg. not tripping on lower current than 65a) then the fault has to be looked somewhere else.

It is hard to tell which part get in action, the main breaker or the rcbo, as they are mechanically connected.

 

What now comes into my mind is that there IS an leak fault, even if there is no earthing in the CU.

If one of the outdoor unit is connected to earth (home harness, or wire into ground, or bonded to some roof iron) and a little leak is ok but many applicances it all counts and once above the 20mA (The OP said he has the dial on 20) then the rcbo would trip as the current in the N is not equal as L.

 

To the OP. Do measure the current in both lines,  Live and Neutral, each one.

 

 

 

As best I can remember the only thing grounded is the shower heater and that is grounded by a green wire connected to a 2 meter copper pole driven into the ground. The water pump used to be grounded but when it wore out the newer version has no way to ground nor any instructions to do so.

[lopburi3]

35 minutes ago, livram said:

The RCBO does NOT move into the Red section. There is no label on the red bit. It is set to 20 mAmp. It looks like it has an OFF position. Last week the PEA sparky was here and my daughter said he pulled out the RCBO dial unit and cleaned it off but no improvement.

 

 I am not sure about polarity. 

If it has an off position put it there and test again to make sure it is not cumulative leakage causing the RCBO to trip.  If no off position expect there is a 30ma position (normal setting for most)?  That would allow a bit more leakage.  

[Crossy]

OK, polarity looks like one thing to tick off the list ????

 

[Crossy]

@Metropolitan I'm thinking the same (or a N-E fault somewhere), but let's get all the measurements done before heading off down a very difficult route.

 

A N-E fault would display characteristics very like what our OP is seeing, seemingly random but somehow load-related trips.

 

Is there any way to un-link the RCD actuator (far left)? What's that just above the actuator lever?

 

 

[Crossy]

Can we have a closer photo of the neutral bar please?

 

Is it physically bolted to the metal box with no insulator?

 

The unused bar at the bottom looks like it's mounted on plastic.

 

[livram]

32 minutes ago, Crossy said:

Can we have a closer photo of the neutral bar please?

 

Is it physically bolted to the metal box with no insulator?

 

The unused bar at the bottom looks like it's mounted on plastic.

 

Here are some more photos. You cannot see it but the bottom bar is being used by the brown wire which is the #10 breaker. Also I noticed that #9 is spiced and that is the breaker for the backroom including the power point for water pump.

 

I do not see any way to turn off the RCB dial, it has settings for 5, 10, 20, and 30. I have moved dial to 30 mAmp setting for now. There is a tiny screw under the RCB on one side next to the main breaker.

[Metropolitian]

58 minutes ago, Crossy said:

Can we have a closer photo of the neutral bar please?

 

Is it physically bolted to the metal box with no insulator?

 

The unused bar at the bottom looks like it's mounted on plastic.

I can confirm about this style CU, the neutral is isolated from the metal box.

That black (in fact brownish) around the busbar is the plastic insulator.

The bottom busbar is directly screwed on the metal box.

 

 

1 hour ago, lopburi3 said:

If no off position expect there is a 30ma position (normal setting for most)? 

It is a 'USA" style , and on this model starts at 5 and only goes to 25mA. (We Europeans, with our -dry- humor, can handle 30mA.  )

 

 

Edit:

Just see the new pictures and I stand corrected .. ???? This model can be set on 30mA.
I have seen many GFCI (American RCBO) that doesn't have the 30.

 

Edited April 11, 2020 by Metropolitian

[Crossy]

1 minute ago, Metropolitian said:

I can confirm about this style CU, the neutral is isolated from the metal box.

 

Yeah, it's clearer in the new photos, I was worried that the installer had used what should be the earth bar as neutral.

 

Bottom bar looks solidly bolted to the metalwork (so it's Earth)

 

5 minutes ago, livram said:

You cannot see it but the bottom bar is being used by the brown wire which is the #10 breaker.

 

This worries me, is that bar actually connected to a wire, and what does that wire do?

[livram]

3 minutes ago, Metropolitian said:

I can confirm about this style CU, the neutral is isolated from the metal box.

That black (in fact brownish) around the busbar is the plastic insulator, with separate screws mounted on two 'lips'.

The bottom busbar is directly screwed on the metal box, on a wide 'lip'.

 

 

It is a 'USA" style , and on this model starts at 5 and only goes to 25mA. (We Europeans, with our -dry- humor, can handle 30mA.  )

 

2nd photo settings show 5,10,20,30. Have now set to 30 until we resolve issue.

[livram]

1 minute ago, Crossy said:

 

Yeah, it's clearer in the new photos, I was worried that the installer had used what should be the earth bar as neutral.

 

Bottom bar looks solidly bolted to the metalwork (so it's Earth)

 

 

This worries me, is that bar actually connected to a wire, and what does that wire do?

The brown wire on #10 is for the newer 9.2k BTU A/c in the guest room which runs 24/7 and was installed Sep 2019. Problems started 2 or 3 weeks ago when weather turned really hot and all 3 B/R's started running A/C most of the time. When water heater, water pump turned on-main breaker trips. Also trips sometimes when 3 A/C running and microwave and/or rice cooker turned on. Trips instantly.

 

Except for the brown wire from #10 connecting I see no other wires connected to bottom wire. The #10 connection was done by A/C installer and not PEA electrician.

[Metropolitian]

16 minutes ago, livram said:

Here are some more photos.

Thanks.

 

16 minutes ago, livram said:

You cannot see it but the bottom bar is being used by the brown wire which is the #10 breaker.

Are you really sure? As I see in the picture none of those 11 screws is in use, perhaps it just looks like it but it isn't.

And if so, then you would be shocked on touching the metal box.

You did say the light-pen did light up on a distance of 6 inch, that's very sensitive and I do have one of those pen too and not relying on it anymore.

At first I was thinking, yeah that box is life but none of that because you eventually said it is not light up at the neutral bar and I know the actions of those chinesium light-pen.

 

16 minutes ago, livram said:

 

Also I noticed that #9 is spiced and that is the breaker for the backroom including the power point for water pump.

 

That one worries me, it looks too small for feeding the backroom and pump.

 

 

16 minutes ago, livram said:

 

 

[Crossy]

OK I'm getting confused here:-

 

Is there anything connected to the brass bar in this photo

 

 

[livram]

7 minutes ago, Crossy said:

OK I'm getting confused here:-

 

Is there anything connected to the brass bar in this photo

 

 

I am sorry for not being clearer. The ONLY wire connected to the bottom brass bar is the brown wire for the 9K A/C. NO other wires are connected to the brass bar. The red wire from #9 looks like it is connected but is just loops around to the top and is not connected to the brass bar.

[Metropolitian]

Question to the OP:

 

Do you see an red indicator at the Shunt Release switch after each trip? (The most left one)

[Crossy]

2 minutes ago, livram said:

I am sorry for not being clearer.

 

No worries, can you just post a photo of the brown wire connection.

 

[Crossy]

Just now, Metropolitian said:

Do you see an red indicator at the Shunt Release switch after each trip? (The most left one)

 

Ah, that's what the little square thing is ????

 

[livram]

12 minutes ago, Crossy said:

 

No worries, can you just post a photo of the brown wire connection.

 

My apologies, I got up on the ladder for a good look and picture and the #10 brown wire does NOT CONNECT to the brass bar. NO wires connect to the brass bar.

 

The only thing different is that #9 RED wire loops around opposite of the other neutral wires and is spliced to a blue colored wire..

 

Also I see no red indicator light at all next to the shunt release

[Crossy]

3 minutes ago, livram said:

Also I see no red indicator light at all next to the shunt release

 

It only comes on after a trip, when you reset it goes out. So you need to make things trip and check.

 

It's not actually a light, it's a red bit of plastic that becomes visible in that little window.

 

This should tell us for certain whether the trip is over-current or earth leakage.

[lopburi3]

4 minutes ago, Crossy said:

 

It only comes on after a trip, when you reset it goes out. So you need to make things trip and check.

 

It's not actually a light, it's a red bit of plastic that becomes visible in that little window.

 

This should tell us for certain whether the trip is over-current or earth leakage.

Just press the test button.  That should trip breaker and if there is a light put it on.  Can immediately reset.

 

Once you find light you can do a real world test as above to see if that light comes on when you have your reported outages during heavy usage.

Edited April 11, 2020 by lopburi3

[Crossy]

2 minutes ago, lopburi3 said:

Just press the test button.  That should trip breaker and if there is a light put it on.  Can immediately reset.

 

Now I know I'm going stir-crazy!!

 

But doing that doesn't help us to know whether the real trip is earth or overload.

.

[livram]

Some voltage readings taken from receptacle plug inside house:

 

All 3 A/C's on plus few lights etc: 225/227V - ran fine nothing tripped.

 

All 3 a/c's on then switched on shower heater and water pump: 224/226v - Main breaker tripped after 2 minutes.

 

All 3 a/c's on plus microwave and rice cooker: 212/214V for 2 minutes but nothing tripped.

 

 

[Crossy]

Voltages look OK, any current measurements?

 

When it tripped was there a red indicator showing on the shunt release?

 

[livram]

5 minutes ago, lopburi3 said:

Just press the test button.  That should trip breaker and if there is a light put it on.  Can immediately reset.

 

Once you find light you can do a real world test as above to see if that light comes on when you have your reported outages during heavy usage.

I pressed the test button and breaker tripped but nowhere do a see any red light or red plastic glowing. I only see a couple of small red logo's on the RCD.

[lopburi3]

2 minutes ago, livram said:

I pressed the test button and breaker tripped but nowhere do a see any red light or red plastic glowing. I only see a couple of small red logo's on the RCD.

Are those small red logo's on all the time or just when tripped?

[Crossy]

Isn't this it?

 

[livram]

5 minutes ago, Crossy said:

Voltages look OK, any current measurements?

 

When it tripped was there a red indicator showing on the shunt release?

 

Do you mean by "shunt release" the 3 connected breakers that trip? The last switch at the very end does look like it has a small red light but it is not glowing after tripping with the test switch.

 

I haven't taken any amp readings because my "helper" took off.

[livram]

3 minutes ago, Crossy said:

Isn't this it?

 

That is what I have concluded but I don't see it glowing red after using the test switch.