MCBs tripping randomly?

[UNG]

So the last time I saw a fault like / similar to this was around 35 or so years ago and the memory is a little bit hazy about it but I do recall the problem ended up as a DNO distribution issue

Now to get a bit more background where is this property located is it urban, semi rural or rural, how is the supply delivered is it underground or overhead,

Does this random tripping occur more or only during episodes of wet weather

What connected loads does the garage have, are there any PIR controlled outdoor lights supplied from the garage

While trying to identify the fault have you done any random voltage checks of the main supply at different times to see if there are any large variations that may suggest an external mains issue

 

[Lewis Curle]

So the last time I saw a fault like / similar to this was around 35 or so years ago and the memory is a little bit hazy about it but I do recall the problem ended up as a DNO distribution issue

Now to get a bit more background where is this property located is it urban, semi rural or rural, how is the supply delivered is it underground or overhead,

Does this random tripping occur more or only during episodes of wet weather

What connected loads does the garage have, are there any PIR controlled outdoor lights supplied from the garage

While trying to identify the fault have you done any random voltage checks of the main supply at different times to see if there are any large variations that may suggest an external mains issue

Hello mate thanks for your message.
I live in an semi urban set of new builds on the outside of town. I’m pretty sure all the cables are ran underground because there’s a subby not 100ft from my house.

I do have an outside light that hasn’t work for some time now that is on a pir, I didn’t think to look at that since the 6A MCB baby ever tripped that controls it. I will diss connect it tonight to test!

As far as the voltage checks I seem to get a level 240V when I’ve checked, but I will double check again to be sure!

Cheers, Lewis

 

[marconi]

Hello. Please would you tell me:

1. The make, model and power of your gaming PSU. Do you have more than one?
2. Do you plug them directly into a socket or via a surge suppression socket strip?
3. When you say nothing is on do you mean the PC, IT and gaming equipment including PSU is switched off on the equipment or at the socket?
4. Co-incident with moving the equipment to the sunhouse have you added any equipment or changed any of it?
5. Have you tried leaving the 40A mcb off for a few days to isolate power to the sunhouse and the equipment in there?
6. What white goods do you have ie washer, dryer, dishwasher and microwave? Have these changed recently?
7. Do you have an induction hob?
8. Have you had a smart meter fitted recently or at all?
9. Do your lights ever flicker? Do your neighbours ever?
10. Has any digging been done in the garden near the cable to the sunhouse?
11. Have you had any water leaks or rain water ingress to your home of sunhouse?
12. Who did the electricity supply to the sunhouse? Do you have a test certificate if it was done after the main house? How long is the cable run?
13. Would you say the problem never happened until the shift of equipment to the sunhouse?
14. Do you have an electric vehicle charger?
15. What exactly is fed by each circuit breaker - a labelled picture would be helpful.
16. Do you have air conditioning units or heat pumps?
17. Please post a picture of your supply intake and meter.

My hypothesis is you have a loose line, neutral or earth connection(s) - within or without your property - which is causing high dV/dt of the supply voltage; a or several connected loads have mains filters within them which are reacting to the high dV/dt with a high albeit brief current as their capacitors change their state of charge. I suspect the circuit for the sunhouse since it has used unusually split concentric cable which needs care terminating well. The reliable conduction of a connection or joint can vary with current density.

 

[Lewis Curle]

Hello. Please would you tell me:

1. The make, model and power of your gaming PSU. Do you have more than one?
2. Do you plug them directly into a socket or via a surge suppression socket strip?
3. When you say nothing is on do you mean the PC, IT and gaming equipment including PSU is switched off on the equipment or at the socket?
4. Co-incident with moving the equipment to the sunhouse have you added any equipment or changed any of it?
5. Have you tried leaving the 40A mcb off for a few days to isolate power to the sunhouse and the equipment in there?
6. What white goods do you have ie washer, dryer, dishwasher and microwave? Have these changed recently?
7. Do you have an induction hob?
8. Have you had a smart meter fitted recently or at all?
9. Do your lights ever flicker? Do your neighbours ever?
10. Has any digging been done in the garden near the cable to the sunhouse?
11. Have you had any water leaks or rain water ingress to your home of sunhouse?
12. Who did the electricity supply to the sunhouse? Do you have a test certificate if it was done after the main house? How long is the cable run?
13. Would you say the problem never happened until the shift of equipment to the sunhouse?
14. Do you have an electric vehicle charger?
15. What exactly is fed by each circuit breaker - a labelled picture would be helpful.
16. Do you have air conditioning units or heat pumps?
17. Please post a picture of your supply intake and meter.

My hypothesis is you have a loose line, neutral or earth connection(s) - within or without your property - which is causing high dV/dt of the supply voltage; a or several connected loads have mains filters within them which are reacting to the high dV/dt with a high albeit brief current as their capacitors change their state of charge. I suspect the circuit for the sunhouse since it has used unusually split concentric cable which needs care terminating well.

Wow thanks for taking the time to write all that.

Hello. Please would you tell me:

1. The make, model and power of your gaming PSU. Do you have more than one?
2. Do you plug them directly into a socket or via a surge suppression socket strip?
3. When you say nothing is on do you mean the PC, IT and gaming equipment including PSU is switched off on the equipment or at the socket?
4. Co-incident with moving the equipment to the sunhouse have you added any equipment or changed any of it?
5. Have you tried leaving the 40A mcb off for a few days to isolate power to the sunhouse and the equipment in there?
6. What white goods do you have ie washer, dryer, dishwasher and microwave? Have these changed recently?
7. Do you have an induction hob?
8. Have you had a smart meter fitted recently or at all?
9. Do your lights ever flicker? Do your neighbours ever?
10. Has any digging been done in the garden near the cable to the sunhouse?
11. Have you had any water leaks or rain water ingress to your home of sunhouse?
12. Who did the electricity supply to the sunhouse? Do you have a test certificate if it was done after the main house? How long is the cable run?
13. Would you say the problem never happened until the shift of equipment to the sunhouse?
14. Do you have an electric vehicle charger?
15. What exactly is fed by each circuit breaker - a labelled picture would be helpful.
16. Do you have air conditioning units or heat pumps?
17. Please post a picture of your supply intake and meter.

My hypothesis is you have a loose line, neutral or earth connection(s) - within or without your property - which is causing high dV/dt of the supply voltage; a or several connected loads have mains filters within them which are reacting to the high dV/dt with a high albeit brief current as their capacitors change their state of charge. I suspect the circuit for the sunhouse since it has used unusually split concentric cable which needs care terminating well. The reliable conduction of a connection or joint can vary with current density

Hello. Please would you tell me:

1. The make, model and power of your gaming PSU. Do you have more than one?
2. Do you plug them directly into a socket or via a surge suppression socket strip?
3. When you say nothing is on do you mean the PC, IT and gaming equipment including PSU is switched off on the equipment or at the socket?
4. Co-incident with moving the equipment to the sunhouse have you added any equipment or changed any of it?
5. Have you tried leaving the 40A mcb off for a few days to isolate power to the sunhouse and the equipment in there?
6. What white goods do you have ie washer, dryer, dishwasher and microwave? Have these changed recently?
7. Do you have an induction hob?
8. Have you had a smart meter fitted recently or at all?
9. Do your lights ever flicker? Do your neighbours ever?
10. Has any digging been done in the garden near the cable to the sunhouse?
11. Have you had any water leaks or rain water ingress to your home of sunhouse?
12. Who did the electricity supply to the sunhouse? Do you have a test certificate if it was done after the main house? How long is the cable run?
13. Would you say the problem never happened until the shift of equipment to the sunhouse?
14. Do you have an electric vehicle charger?
15. What exactly is fed by each circuit breaker - a labelled picture would be helpful.
16. Do you have air conditioning units or heat pumps?
17. Please post a picture of your supply intake and meter.

My hypothesis is you have a loose line, neutral or earth connection(s) - within or without your property - which is causing high dV/dt of the supply voltage; a or several connected loads have mains filters within them which are reacting to the high dV/dt with a high albeit brief current as their capacitors change their state of charge. I suspect the circuit for the sunhouse since it has used unusually split concentric cable which needs care terminating well. The reliable conduction of a connection or joint can vary with current density.

Hello mate first of all thanks for taking the time to write all that!

So I’m unsure on my PSU model I will find out tonight
2.

Hello. Please would you tell me:

1. The make, model and power of your gaming PSU. Do you have more than one?
2. Do you plug them directly into a socket or via a surge suppression socket strip?
3. When you say nothing is on do you mean the PC, IT and gaming equipment including PSU is switched off on the equipment or at the socket?
4. Co-incident with moving the equipment to the sunhouse have you added any equipment or changed any of it?
5. Have you tried leaving the 40A mcb off for a few days to isolate power to the sunhouse and the equipment in there?
6. What white goods do you have ie washer, dryer, dishwasher and microwave? Have these changed recently?
7. Do you have an induction hob?
8. Have you had a smart meter fitted recently or at all?
9. Do your lights ever flicker? Do your neighbours ever?
10. Has any digging been done in the garden near the cable to the sunhouse?
11. Have you had any water leaks or rain water ingress to your home of sunhouse?
12. Who did the electricity supply to the sunhouse? Do you have a test certificate if it was done after the main house? How long is the cable run?
13. Would you say the problem never happened until the shift of equipment to the sunhouse?
14. Do you have an electric vehicle charger?
15. What exactly is fed by each circuit breaker - a labelled picture would be helpful.
16. Do you have air conditioning units or heat pumps?
17. Please post a picture of your supply intake and meter.

My hypothesis is you have a loose line, neutral or earth connection(s) - within or without your property - which is causing high dV/dt of the supply voltage; a or several connected loads have mains filters within them which are reacting to the high dV/dt with a high albeit brief current as their capacitors change their state of charge. I suspect the circuit for the sunhouse since it has used unusually split concentric cable which needs care terminating well. The reliable conduction of a connection or joint can vary with current density.

I will put my pc details in the chat for you to see sir! First of all thanks for taking the time to write all that.
1. See picture
2. It is all plugged in via a surge suppression strip, i have only changed that as of a couple of days ago and the issue is still happening.
3.I leave my PC and everything plugged in and turned on at the socket.
4. My PC has never tripped the inside circuits of my house before, The garage in the past has been found with the MCB off but never this much.
5. I havent left it off for more than a day no.
6. Yeah we have all of the above but no they have not been touched since we moved in.
7. We have a Gas hob
8. We have a smart meter just plugged into the sockets in the kitchen, we have recently plugged it back in a few weeks ago, however i unplugged it again to see if it was causing the issue and it appears to not have had any effect as its still tripping.
9.Not that i know off.
10. No digging has been done since we moved in,
11.No water that i can tell.
12.Its definitely gotten worse since the equipment was moved in, But we have used the sun house a lot in the past and i must say it was rarely off but it has happened.
13.Not never happened just happening a lot more now.
14. NO
15. The 40A one in the picture is the garage one but ill get a laballed pictuire.
16.No
17. I will get those photos.

Thanks hope that helps please ask any more questions that you want to. I appreciate the help!


Also i redone the IR test and took the dodgy outside light down and its still tripping. The IR test again came back perfect.

 

[Lewis Curle]

Hello. Please would you tell me:

1. The make, model and power of your gaming PSU. Do you have more than one?
2. Do you plug them directly into a socket or via a surge suppression socket strip?
3. When you say nothing is on do you mean the PC, IT and gaming equipment including PSU is switched off on the equipment or at the socket?
4. Co-incident with moving the equipment to the sunhouse have you added any equipment or changed any of it?
5. Have you tried leaving the 40A mcb off for a few days to isolate power to the sunhouse and the equipment in there?
6. What white goods do you have ie washer, dryer, dishwasher and microwave? Have these changed recently?
7. Do you have an induction hob?
8. Have you had a smart meter fitted recently or at all?
9. Do your lights ever flicker? Do your neighbours ever?
10. Has any digging been done in the garden near the cable to the sunhouse?
11. Have you had any water leaks or rain water ingress to your home of sunhouse?
12. Who did the electricity supply to the sunhouse? Do you have a test certificate if it was done after the main house? How long is the cable run?
13. Would you say the problem never happened until the shift of equipment to the sunhouse?
14. Do you have an electric vehicle charger?
15. What exactly is fed by each circuit breaker - a labelled picture would be helpful.
16. Do you have air conditioning units or heat pumps?
17. Please post a picture of your supply intake and meter.

My hypothesis is you have a loose line, neutral or earth connection(s) - within or without your property - which is causing high dV/dt of the supply voltage; a or several connected loads have mains filters within them which are reacting to the high dV/dt with a high albeit brief current as their capacitors change their state of charge. I suspect the circuit for the sunhouse since it has used unusually split concentric cable which needs care terminating well. The reliable conduction of a connection or joint can vary with current density.

 

[marconi]

Thank you.

For now it would be helpful if you opened up each CU (House and sun house) and with power off carefully inspect where the lower terminals of mcbs connect to busbar to confirm they are clamping or being screwed onto busbar. Tighten up all lower mcb screws and note down any which appeared loose. Do the same for RCDs and mains switches

Check solidity and security of neutral and cpc connections by tug and wiggle check. Again note any loose ones and tighten up. While you are at it remake the neutrals for the split concentric at the house CU.

With all sunhouse IT and gaming powered up go to intake and meter board and gently wiggle - not tug - the tails and feeds. Any trips?

Is the surge socket strip a simple type with a glowing neon or is it a professional one which contains inductors, capacitors and over voltage protection Eg by Olson?

Try plugging your sunhouse IT and gaming equipment directly into mains instead of via the surge socket strip. Leave for say a few days or until another mob trip happens.

Try leaving your IT and gaming equipment unplugged from mains for a few days or until trip happens.

Try turning off main switch of sunhouse CU but house 40A mob on for a few days or until trip happens.

What is the answer to 12 please? I will not give you a hard time if it was you.

Probably enough for now.

 

[Lewis Curle]

Thank you.

For now it would be helpful if you opened up each CU (House and sun house) and with power off carefully inspect where the lower terminals of mcbs connect to busbar to confirm they are clamping or being screwed onto busbar. Tighten up all lower mcb screws and note down any which appeared loose. Do the same for RCDs and mains switches

Check solidity and security of neutral and cpc connections by tug and wiggle check. Again note any loose ones and tighten up. While you are at it remake the neutrals for the split concentric at the house CU.

With all sunhouse IT and gaming powered up go to intake and meter board and gently wiggle - not tug - the tails and feeds. Any trips?

Is the surge socket strip a simple type with a glowing neon or is it a professional one which contains inductors, capacitors and over voltage protection Eg by Olson?

Try plugging your sunhouse IT and gaming equipment directly into mains instead of via the surge socket strip. Leave for say a few days or until another mob trip happens.

Try leaving your IT and gaming equipment unplugged from mains for a few days or until trip happens.

Try turning off main switch of sunhouse CU but house 40A mob on for a few days or until trip happens.

What is the answer to 12 please? I will not give you a hard time if it was you.

Probably enough for now.

Ok mate i will do as you say at some point today and come back with results!

The surge protection strip is LOGIK which i think is just a standard one of the shelf electrical wholesalers.

I will try and see if the error occurs when nothing is plugged into the sunhouse, Can a bad PC power unit cause things like this to happen?

So the cable to the sunhouse i know little about as it was all here when we moved in. The sun house is an extension of the old garage so i imagine the its the original cable from when the whole place was built. I have considered wiring a temp 6mm SWA from my DB to the garage. To see if the duct or something is crushing the cable underground where i cant see but surely any issues would show up on the testing i have done?

Again thanks for taking the time i will get back to you later today

 

[marconi]

High performance high power Pc and gaming power supplies do not last forever. They contain capacitors which are worked hard and run hot which reduces their life. One might expect 20000 hours life from the PSU but considerably less if the PSu is left on all the time. One sign of failing capacitors is mcb tripping. How old are your power supplies and do you leave them powered up all the time? Mcbs often trip faster than fuses rupture.
This is why some time with your equipment unplugged would be helpful.

what is the ambient temperature like in your sunhouse? Does it get quite warm at times or has it in the past ie over say 18-21C? Are the fans working and any filters clear of dust And unobstructed? Check there is good air flow around PSus and that one does not suck in the hot air from the other.

Last, these sort of power supplies have high inrush current when turned on. The value depends on where in the mains cycle they are energised and the state and polarity of charge on the capacitor. If there was a loose connection then it could be inrush current is tripping the mcb.

 

[Bob Geldoff1234]

It might be worth ruling out faulty breakers.The 40amp one could be very sensitive and the others that trip randomly could be going the same way.Maybe worth swapping out the 40amp breaker for a new one to see if that cures it?

 

[Lewis Curle]

It might be worth ruling out faulty breakers.The 40amp one could be very sensitive and the others that trip randomly could be going the same way.Maybe worth swapping out the 40amp breaker for a new one to see if that cures it?

I’ve already swapped it out mate! But thanks for the advice

 

[marconi]

Corsair CX750M (2021) Power Supply Review - https://www.tomshardware.com/reviews/corsair-cx750m-2021-power-supply-review/2

The inrush current from cold start at 230V ac for a single Corsair cx750M bronze according to tomsharware is circa 90A. It could be higher if the capacitors are charged such that their voltage adds to the mains.

 

[Lewis Curle]

Corsair CX750M (2021) Power Supply Review - https://www.tomshardware.com/reviews/corsair-cx750m-2021-power-supply-review/2

The inrush current from cold start at 230V ac for a single Corsair cx750M bronze according to tomsharware is circa 90A. It could be higher if the capacitors are charged such that their voltage adds to the mains.

Ok mate thanks for looking into this! I am going to test the theory of the my pc set up now being plugged in for a couple days to see if it trips. It will give it chance to discharge fully as well.

I have fully reconnected the two DBS involved to make sure it alls all tight and it tripped shortly after redoing it.

So another thing checked of the list! I will keep you informed if my discoveries

 

[Lewis Curle]

Corsair CX750M (2021) Power Supply Review - https://www.tomshardware.com/reviews/corsair-cx750m-2021-power-supply-review/2

The inrush current from cold start at 230V ac for a single Corsair cx750M bronze according to tomsharware is circa 90A. It could be higher if the capacitors are charged such that their voltage adds to the mains.

So I’ve done some testing over the past couple of days.

I totally unplugged my pc set up for two days, in that time the garage MCB has not tripped once. I spent a night in there with some mates and we had the space heater, all the lights and had things like phones charging and the MCB stayed on with no issues.

I’ve been back in tonight to try and game, I got home around 6pm. Turned my pc on and had it play a YouTube video whilst I ate and put my kid to bed. It was on for around two hours but I wasn’t at the pc, I went in to game just before 8 and within 5 minutes of me playing not even a strenuous game the breaker tripped.

So my question is now, does a pc pull more power when playing games? I assume it does when playing a graphics intensive game. So what I am now doing is having my pc plugged in alone with no monitors, just on standby to see if the MCB will trip. If this is the case I’m going to maybe move my pc back into the house for a few days to see if it trips anything.

My worry is that I move it back into my house and it just works with no issues because I don’t know where to go if that’s the case. I would rather it was the PCs power unit just so i can change it and be done with all of this

I hope all of that made sense and would appreciate any more advice you may have sir.
Thanks, Lewis

 

[marconi]

Thank you for the update. I will have a think and let you know tomorrow. Just speaking generally, as computers work harder at number crunching their power consumption will increase. This is of course what is happening in video games especially those with high fidelity graphics and game physics ie dealing with motion, collisions, interactions with objects and background and not forgetting the player(s) input.

How many Corsair power units where powered up and supplying when you tried a game this evening?

And to be clear which mcb tripped?

Please tell me the type of the 40A MCB which supplies the sunhouse and also the rating and type of the mcb for the ring in sunhouse. Eg 40A type B and 32A type B? It may be the waveform of the current drawn by the corsairs power supplies has a form which has a high crest factor which means it has a high peak current compared to the average current. If this is the case The MCBs responds to waveform as if this was a short circuit And trips. But this is my thinking at the moment So no changes yet please.

how long is the cable run from house db to sunhouse db? What mm2 is the cable? Volt drop with increasing current may be a factor. The Corsair has an input voltage range something like 100 to 230V without the need to change any settings. What happens is that at lower voltages the current increases as required to deliver the same power output.

ps: crest factor is peak current/rms current

 

[James]

Can you post a picture of the 40A breaker that is tripping?

 

[nicebutdim]

Can you post a picture of the 40A breaker that is tripping?

Been thinking, perhaps, along similar lines, but scrolled up and see the OP posted images in #6. It is indeed a 40A MCB.

 

[Lewis Curle]

Thank you for the update. I will have a think and let you know tomorrow. Just speaking generally, as computers work harder at number crunching their power consumption will increase. This is of course what is happening in video games especially those with high fidelity graphics and game physics ie dealing with motion, collisions, interactions with objects and background and not forgetting the player(s) input.

How many Corsair power units where powered up and supplying when you tried a game this evening?

And to be clear which mcb tripped?

Please tell me the type of the 40A MCB which supplies the sunhouse and also the rating and type of the mcb for the ring in sunhouse. Eg 40A type B and 32A type B? It may be the waveform of the current drawn by the corsairs power supplies has a form which has a high crest factor which means it has a high peak current compared to the average current. If this is the case The MCBs responds to waveform as if this was a short circuit And trips. But this is my thinking at the moment So no changes yet please.

how long is the cable run from house db to sunhouse db? What mm2 is the cable? Volt drop with increasing current may be a factor. The Corsair has an input voltage range something like 100 to 230V without the need to change any settings. What happens is that at lower voltages the current increases as required to deliver the same power output.

ps: crest factor is peak current/rms current

The MCB in the home DB feeding the garage is a 40A type B that is using a 6mm core live and a bunch of little neutrals. Inside the sun house itself it’s on a 16A MCB currently. The original circuit in the sun house was just a 16A radial, but I changed it to a ring and made the MCB a 32A for a while but I have since changed it back to the 16A(all type Bs)

I made the change because I wanted to be able to have more on the circuit, without it being an issue. I have changed it back to a 16A MCB but I’ve left it as a ring instead of the radial. It’s been about three weeks since I made the move Into the sun house and it worked for about two weeks and now this issue has been going on for a week.

I’m confident the cabling is all good in the sun house and the cable going to the sun house has tested out good as well. I put it out of my mind that my PC set up could be the issue since it’s worked perfectly when it was in my house on the upstairs ring main.

I’m having my brother round on Thursday and he is bringing his pc. He’s going to plug his pc into my setup and see if we have the same issue. If we don’t then it just be my pc.

Thanks all for your replies! I really do appreciate you taking the time to help me out.

 

[marconi]

Do you have a fridge in the sun house?

 

[Lewis Curle]

Do you have a fridge in the sun house?

I do but it and the freezer is not plugged in, hasn’t been for a while!

 

[marconi]

How many Corsair power units where powered up and supplying when you tried a game yesterday evening?

Do you have LED lighting in the sunhouse? If you do how many lamps? Are they normally on when you are gaming?

LED lamps have a high crest factor waveform too.

I will await your post after Thursday's trial.