3 minutes ago, dropkick said:

Good point , isetech .  Which begs a new question, what is the magnitude and quality of the incoming supply when the the grid starts feeding again from Eskom?  Maybe the gas arresting part of a surge protector strikes because of this.

Only way to find out is next load shedding session switch  the Main breaker off , and only re- connect manually after the end of loadshedding. If ok, it's a giveaway that the transient state of Eskom supply when they re-connect is ungracefull/unstable.

 

Should this be the case , the irony behind this is that the surge protector /ELD  is actually performing a critical function , that is , protecting the household. Just a thought.

2 hours ago, dropkick said:

Good point , isetech .  Which begs a new question, what is the magnitude and quality of the incoming supply when the the grid starts feeding again from Eskom?  Maybe the gas arresting part of a surge protector strikes because of this.

Only way to find out is next load shedding session switch  the Main breaker off , and only re- connect manually after the end of loadshedding. If ok, it's a giveaway that the transient state of Eskom supply when they re-connect is ungracefull/unstable.

 

I did switch of the mains and back on a few mins after loadshedding stopped. The earth leakage did not trip. 

2 hours ago, isetech said:

People experiencing the earth leakage tripping at the end of load shedding.

Please be more specific with the type and manufacturer of earth leakage ... is it a big wide old Heinemann (CBI) ... with or without an earth wire at the bottom ... a thinner unit which drops the lever to the bottom ... or is it the new one which trips half and has to be reset by pushing the lever to the bottom then up to reset.

Do you have a chint or ABB or schnieder ... lesco ... major tech  etc etc ?

What is leakage current when the unit is in general daily use? 

DO you have surge arrestors in your DB ... at each plug point ? 

If you have those ellies red plug tops ... have you checked that the 2 light are on as per the instruction. 

DO you have old VIR wiring and metal piping in the roof or do you have PVC wire in PVC conduits ... or twin +e with bare earth wires with no sleeve on the bare earth pushed into pvc boxes ... or do you have surfix where the sparkie hasnt taped where he stripped with the knife.

Do you have a stove connected to the earth earth leakage ... with a plate that you havent used in a long time.

Is your geyser hot and cold water pipes bonded and earthed properly ?

How long is the piece of string ... what is the level of leakage on your property  or just the earth leakage unit ? 

It would be interesting to see if it is a specific type or brand. 

 

 

Will have a look at this post a bit later to answer some of your questions 

2 hours ago, dropkick said:

Good point , isetech .  Which begs a new question, what is the magnitude and quality of the incoming supply when the the grid starts feeding again from Eskom?  Maybe the gas arresting part of a surge protector strikes because of this.

Only way to find out is next load shedding session switch  the Main breaker off , and only re- connect manually after the end of loadshedding. If ok, it's a giveaway that the transient state of Eskom supply when they re-connect is ungracefull/unstable.

 

I have a voltmeter permanently attached to my grid side. I notice quite often after load shedding my voltage is low - around 195V or so, then it picks up.

load shedding is like switching off a huge compressor ... people think it is only when the power is switched back on ... the ripple effect of suddenly dropping a huge load ... has a way bigger impact on the grid than you are aware of ... dont forget when your power is switched on ... somewhere close by is being switched on.

I was called to a factory because all the VSD's on every single machine would switch off  at exactly ... 4.03 am every single morning ... I connected the PQA at 3.30 am and recorded the event ... We found out that a huge compressor 2 blocks away would switch off at that time ... was it that or something else ... the cost to install filters was out of the budget ... so everyday they just reset all the VSD's,

I would be interested to hear comments on these statements from electrical engineers on this platform. 

 

 

7 hours ago, isetech said:

load shedding is like switching off a huge compressor ... people think it is only when the power is switched back on ... the ripple effect of suddenly dropping a huge load ... has a way bigger impact on the grid than you are aware of ... dont forget when your power is switched on ... somewhere close by is being switched on.

I was called to a factory because all the VSD's on every single machine would switch off  at exactly ... 4.03 am every single morning ... I connected the PQA at 3.30 am and recorded the event ... We found out that a huge compressor 2 blocks away would switch off at that time ... was it that or something else ... the cost to install filters was out of the budget ... so everyday they just reset all the VSD's,

I would be interested to hear comments on these statements from electrical engineers on this platform. 

 

 

Interesting , but important post.  The subsequent 'tripping' of the drives and reset is in my opinion is the lesser of 2 evils , the other eveil being not having internal drive transient protection at the risk of damaging the drive.

Why your post is important is that 'nuisance' tripping as people call it , is not so  nuisance after all , there's reasons for it. 

As I have said before ... people think this load shedding is just a nuisance ... but in reality it is costing companies a lot more than we know.

Another example ... lamps on printing machines @ R1000 a pop ... when you standing in the factory and you hear that R1000 clicking sound of the lamps as they break. 

I have some bad news ... I decided to connect a power quality analyser (fluke 435) to my house ... because my CBI earth leakage unit at home also trips every time the power switches on after load shedding ... I dont know of any other brand experiencing this problem ... please let me know if you have this problem and what brand of earth leakage. 

I was expecting to see a surge or spike as the power switch off and then another when it switched on  ... it is a lot worse than I thought. 

There is just about every event occurs ... from transient spikes above the wave form to spike within the wave form ... to distorted wave forms ... voltage ranging to as low as 115 VAC.

So there is no need to go looking for a problem in the electrical installation ... the problem is the grid cant seem to handle the load switching ... which results in literally every event possible happening at that point.

It would be interesting to seem what effect it is having on the electronics in the inverters.

 

 

 

 

 

 

 

My current EL is a CBI unit

I have misplaced the older one which was much older and a different brand but im not sure which.

I will try and locate it this weekend and update

What are the other options are there to use for EL though? from your post and tests changing the earth leakage wont solve the issue? But why is not more common then?

 

 

I am trying to determine if the CBI unit is more sensitive than all the other brands ... since the latest wave of load shedding ... all the complaints with regards to earth leakage tripping have been CBI units ... including the CBI unit installed at my house .. hence the reason for hooking up the PQA. 

I have had no complaints from any of my customers with brands like Chint ... Onesto ... ABB etc.

Looking at the event list and waveforms at the point where the power either switches off or on ... I am surprised all the brands are not experiencing the same tripping issue.

I am surprised more complaints about damaged electronic components are not being reported.

8 minutes ago, isetech said:

I am trying to determine if the CBI unit is more sensitive than all the other brands ... since the latest wave of load shedding ... all the complaints with regards to earth leakage tripping have been CBI units

I had a earth leakage problem about two years ago and it was a Onesto tripping. I have three ownestos but only one normally tripped. I replaced it with a ABB and no tripping after that, what I found out on deeper investigation was that my house have a continuous leakage current on the neutral to earth of about 7 to 14 mA. This is problematic because the average earth leakage trips between 22 to 24mA. It would give you a tolerance of 22mA minus the continuous loss of about 14ma = 8mA play for other real faults or transients. When Load-shedding ends and transformer type loads in your house take power they spike a bit and there drops the earth leakage. If you could find out what your continuous leakage is it could give you more answers. 

1 hour ago, Gerrie said:

I had a earth leakage problem about two years ago and it was a Onesto tripping. I have three ownestos but only one normally tripped. I replaced it with a ABB and no tripping after that, what I found out on deeper investigation was that my house have a continuous leakage current on the neutral to earth of about 7 to 14 mA. This is problematic because the average earth leakage trips between 22 to 24mA. It would give you a tolerance of 22mA minus the continuous loss of about 14ma = 8mA play for other real faults or transients. When Load-shedding ends and transformer type loads in your house take power they spike a bit and there drops the earth leakage. If you could find out what your continuous leakage is it could give you more answers. 

How did you find out what your continuous earth leakage is? What equipment did you use? 

56 minutes ago, PowerUser said:

How did you find out what your continuous earth leakage is? What equipment did you use? 

Don’t do this unless you are a qualified electrician. I use to have a Axpert off-grid inverter with a permanent earth/neutral bonding point. You can test the current flow in that bonding point by disconnecting the link and connect a multi meter that acts as the bonding link the meter must have a mA a/c range, the multi meter will now act as the earth/bonding link and current will start flowing if you have circuit breakers that is feeding loads.

Switch off all circuit breakers as well as inverter, connect multi meter and reading should be zero.

Step 1 - With all breakers switched off in DB (Reading should be zero if not something is still on)

Step 2 - Switch on supply to inverter (You might get small 1mA reading)

Step 3 - Switch on Main breaker and check reading (mA reading might be slightly higher like 2mA)

Step 4 - Switch on next breaker and check reading (carry on until all breakers are switched on, and keep checking reading.)The reading when all breakers is on will be the total leakage current. 

I digged up my notes when I tested my  system and the reading ended up on 15.4mA which is not far of 22-24mA tripping current.

Hope this makes sense

You can also test your leakage with a suitable clam current meter, by clamping around both the neutral and live from your RCD. It has to be big enough to fit both wires, and sensitive enough to measure mA accurately.

I might have found the problem ... waiting for the electricity department to arrive.

After the last lot of load shedding ... the earth leakage tripped again ... this time all the lights in the house were flickering.

I scanned the system with a thermal imager ... and spotted a hot connection on the neutral outside on the overhead power line ... reported it.

There have been over 900 voltage dip events recorded on the PQA.

Lets see if the problems goes away after they have replaced the airdac connector (where the hot spot was detected) ... now to try explain the issue to the electrician. 

 

 

Problem solved ... fuse and wiring on the pole replaced "again". 

1 hour ago, isetech said:

Problem solved ... fuse and wiring on the pole replaced "again". 

You are lucky they came so quick to solve the problem, in Alberton where I stay oh boy🙈🤣🤣

On 2021/11/19 at 9:04 AM, isetech said:

I might have found the problem ... waiting for the electricity department to arrive.

After the last lot of load shedding ... the earth leakage tripped again ... this time all the lights in the house were flickering.

I scanned the system with a thermal imager ... and spotted a hot connection on the neutral outside on the overhead power line ... reported it.

There have been over 900 voltage dip events recorded on the PQA.

Lets see if the problems goes away after they have replaced the airdac connector (where the hot spot was detected) ... now to try explain the issue to the electrician. 

 

 

Fascinating, but also advantageous that you have such a tool.

This may or may not be the same issue that the original poster has with his tripping earth leakage, for his and many others with the same problem.
But I think definitely low voltage surges (spikes?) are the cause of most issues.

Is my thinking correct in, say, an old fridge with compressor, a low voltage on startup (caused by return of load shedding) will cause a high spike in current to operate the fridge (to maintain the voltage/amperage balanced relationship, aka rated power or WATTS of the device)?

Thus the original "low leakage to earth" let's assume 10mA could spike as high as 20mA because of the increase in current?
 

16 minutes ago, jacquesretief said:

Fascinating, but also advantageous that you have such a tool.

This may or may not be the same issue that the original poster has with his tripping earth leakage, for his and many others with the same problem.
But I think definitely low voltage surges (spikes?) are the cause of most issues.

Is my thinking correct in, say, an old fridge with compressor, a low voltage on startup (caused by return of load shedding) will cause a high spike in current to operate the fridge (to maintain the voltage/amperage balanced relationship, aka rated power or WATTS of the device)?

Thus the original "low leakage to earth" let's assume 10mA could spike as high as 20mA because of the increase in current?
 

Thanks for bumping this thread, I have been meaning to reply as Im still looking for someone in the Centurion area to sort out this issue. But since there was no loadshedding since then it became less urgent.

My fridge was bought new in 2017 when we moved into the place, so I doubt it is the fridge. That said I just placed an order for an ellies fridge and tv safe units. That should then take the fridge out of the equation. I will let you know if anything changes.

 

Failing that I will still need someone to install a type of mains delay switch, where the power is restored a few minutes after load shedding. Or something like @Acuario posted, but I still cant find anything locally. Going to try in the UK as I have friend returning this month.

 

22 minutes ago, rodga said:

Thanks for bumping this thread, I have been meaning to reply as Im still looking for someone in the Centurion area to sort out this issue. But since there was no loadshedding since then it became less urgent.

My fridge was bought new in 2017 when we moved into the place, so I doubt it is the fridge. That said I just placed an order for an ellies fridge and tv safe units. That should then take the fridge out of the equation. I will let you know if anything changes.

 

Failing that I will still need someone to install a type of mains delay switch, where the power is restored a few minutes after load shedding. Or something like @Acuario posted, but I still cant find anything locally. Going to try in the UK as I have friend returning this month.

 

Cool, no problem. I am an electrician in Durban suffering with this problem with a customer, so trying to learn as much as I can before I try and resolve this repeating problem. The idea of measuring existing natural floating problem will be my first go to. I think it could be an age old watercooler fridge causing the sensitivity (over spike in current leakage).

So I will test first for existing current leakage to earth, and then isolate the circuits. I will then either isolate the machine/components and insulation test at 240v and see what low resistance is letting all this surplus current leak to earth. 

I had the same problem but never got clear feedback from the installer / electrician what the problem was and what caused.  What I do know is my month-old inverter was removed with burnt terminals and replaced with a brand spanking new unit. I can only suspect the inverter was damaged due to a wiring fault (like mains on the inverter output side?). When the new unit was installed it worked perfectly - not too sure if it was the replacement or yet another DB board rewire that fixed the problem for good.   

If your earth neutral bonding relay switches a bit too slow or fast couldn't it be a cause of the EL tripping? 

I was also told that a inverter prefer a very specific type of EL. I cannot remember the different types but the one have only a little "sine wave" inside a rectangular block, sign on, that model doesn't work so well on a inverter. Then you get the model with the "sine wave" sign but under the sign there are 2 little humps looks like boobs, also in a rectangular block. To the right of the block there is a type of quarter wave going down. Sound like these models works better with inverters.

My ELs are CBi 63A C2 OA17A and sounds like they work a bit better.

Hope it makes sense or google the part nr for the pictogram. 

On 2022/02/03 at 10:24 PM, Vaal said:

If your earth neutral bonding relay switches a bit too slow or fast couldn't it be a cause of the EL tripping? 

I was also told that a inverter prefer a very specific type of EL. I cannot remember the different types but the one have only a little "sine wave" inside a rectangular block, sign on, that model doesn't work so well on a inverter. Then you get the model with the "sine wave" sign but under the sign there are 2 little humps looks like boobs, also in a rectangular block. To the right of the block there is a type of quarter wave going down. Sound like these models works better with inverters.

My ELs are CBi 63A C2 OA17A and sounds like they work a bit better.

Hope it makes sense or google the part nr for the pictogram. 

And has anybody tried this EL  model yet? 

How many power surge plugs do you have? The red ones with the lights.