PME PEN fault - Garo tripping out - Diverted Neutral Current....

Is this a PEN fault? Do we have diverted neutral current? Lets investigate!!!
This is a call out from today looking at an operating Garo PEN fault detector.
Lets take a look at what GN3 advises and how I approach it onsite. Please note I couldn't record everything due to safety while I work and privacy for the customer.
These faults can present danger to electricians and others trades/occupiers so its important to understand and be aware of them.
They have existed in the network since its inception but thankfully are very very rare.
But the question is did we find one here?
Some awesome content from ‪@jwflame‬ here kzbin.info?searc...
Plus my prior efforts on the same subject here • Broken PEN conductors ...
• Diverted Neutral Curre...

[@dominicboyle8652]

Thanks Mark, great video. Helpful fault find videos are always good.

[@adriatikkrasniqi1453]

Very impressive video Mark 👍

[@AGRElectrics]

Really interesting! still waiting to see it in the wild myself :D

[@electrician247]

I’ve seen it once or twice. Pre times I shared stuff on the internet lol. Both times a failed joint in the street and both detected and fixed without serious consequences. Always a head scratcher though lol

[@testinstrumentsolutions]

The TIS 859 also has a non contact indicator on it, hold the EF button down and take the black probe to any metal surface it will indicate live or dead 😉

[@electrician247]

Very true! I always forget how much that thing can do!

[@Big-T-]

Here's a situation for you, mate. I installed a 7.5kW Solax hybrid inverter with 2x 5.8kW batteries, performed a board change, and set up a renewables board for the PV. Testing the results for the PV CU are as follows: R1+R2 = 0.35 ohms IR = 999> L-N, L-E, N-E ZE = 0.18 ohms PFC = 876A ZS = 0.53 ohms RCD = x1 - 13ms, x5 - 13ms, Hager 40A RCBO, Type C. The circuit is a 3-core, 6mm SWA, 25m run through the loft into buried ducting leading to the barn. Ducting, SWA for AC, and Cat 5 were installed by the customer. While the system runs smoothly during the day, generating PV and charging the batteries and discharging to the property with no issues, there are tripping issues at night. Monitoring the system, I observed 'grid lost' and 'grid frequency fault' messages. The customer set charge times between 2-5 am, and the fault occurred at 2:01 am. I've looked into 411.3.3 in BS7671, which outlines RCD protection requirements. My interpretation suggests that we might not need it since we exceed 32A. Any advice on where to look for a solution would be much appreciated."

[@electrician247]

So long as your final circuits in the PV board are RCD protected as normal you don’t need one on the supply to the hybrid if you have used SWA. Lots of inverters will peak the 30mA on an RCD/rcbo. Although I’ve never had a problem of that on solax when the cable type has required an RCD. Is it possible the charge inverter on the AC side is damaged? The solax hybrids themselves don’t require RCD protection. Nor does Swa What size inverter are you using ? Is it possible you are seeing inrush on the MCB rather than earth leakage current.

[@Big-T-]

@@electrician247 The PV board is equipped with a 100A main switch and a C40 RCBO for the 7.5kW inverter, which is the only circuit within the board. There is an armored Cat 5 cable glanded into it, terminated with an RJ45 inside the CU connected to an RJ45 coupler for the CT. Initially, I thought the issue might be related to inrush currents, which led me to switch from a type B to a type C. However, it tripped again the following night under the exact same fault/conditions. Unfortunately, we don't have an earth leakage device, and the company is unwilling to invest in one. How can I check for a faulty inverter charge on the AC side? During the commissioning day, I was on the phone with Solax as the customer faced difficulties registering on the app. Solax suggested a forced discharge, which worked fine. Additionally, I performed a forced charge from the grid on 2 or 3 occasions, each lasting 30 minutes, without any trips. I recall seeing one of your previous videos where you left a monitoring PV device at a customer's property to data log for a few days, a method I would love to employ. However, I am hesitant to cover the expenses myself. Based on what you're saying, could I consider switching the RCBO to a C40 MCB? I'm only out my time 9 months ago, and it's the first time I've heard that you don't need an RCD for SWA. As my journeyman always told me, 'You only start learning properly once you're qualified,' haha. Thanks for the speedy rely.

[@electrician247]

@@Big-T- this is UK specific but SWAT doesn’t require RCD protection unless the earthing arrangement dictates otherwise. With the 7.5kW solax advise a 50A OCPD which has led me to adjust one or two installs we had set at 40A. Is the RCD/breaker tripping in the night? Or the inverter just reporting a fault? It could be the voltage is dropping under the minimum inverter limit over night of the DNO have tapped it down

[@Big-T-]

@@electrician247 The customer is reporting multiple breaker trips at night. He's a controls guy who works for Scottish Power, so he's very keen, haha.

[@electrician247]

@@Big-T- I would go for a fault on the inverter if so had to guess lol.

[@markpritchard5318]

Hi Mark I've just invested in a mft pro have you got a video on how to operate it please

[@anthonybragg]

Unusual call out, I'll be interested in part 2. Do you think in the future that with all these new devices eg PEN fault detection, AFDD that they will only last for a few years before having to be replaced or going faulty?

[@electrician247]

Seems to be how the world works when electronics are involved mate.

[@davideyres955]

This is one of the things that people who think they can do the job of an electrician don’t understand and don’t know how dangerous it is for EV charging.