3 phase 100A power supply - voltage at each phase goes up to 250+ Volts should I be worried?

FaeLLe:

AJJewsbury:

[2] Broken PEN has been something I was paranoid about so I got an ABB device that monitors earth and neutral breaks, I think it is called RC223.

Basically have it to protect the outdoor EV charging point to comply with 18th edition amendment 1; did not want to have someone wandering around touch the car when it is wet and get electrocuted.

Broken PENs are nasty things - not only is there the shock hazard from things that should be earthed, but there's the general issue of anything up to 400+ volts appearing between L & N - which tends to do permanent damage to a lot of equipment. SPD don't help much in that event either - they can only really deal with very short pulses of over voltages - not something that might last for hours or days.

This is why I got the Earth Neutral break monitoring device to disconnect power supply to my EV if there is a break in neutral.

I also considered converting the PME supply to something like TT with an earth rod but then decided that I did not have the resources to maintain the seperate earth connection infrastructure!

The electricity substation is less than 12 feet from my distribution box! So less chances of someone digging the street up between me and the LV board..

I know the regs say it is based on risk assessment but what does that really involve?

Just plugging numbers into a formula and see if you get an answer above or below 1000. The numbers come from whether your situation is rural/suburban or urban, lightning flash density your location (the regs supply a map for the UK), and the features of the last 1km of the network that supplies you (whether underground or overhead and how much of that 1km is HV or LV). I can dig out the details if you're interested.

Hi Andy I would be interested to read up and learn a bit more on this if you can point me to some documentation.


Also keen to understand what my lightning flash density is as I have now installed outdoor WiFi access points all around my land but conveniantly ignored the advise to get a lightnight surge protection device fitted in line with the Ethernet cable.


   - Andy.

 

 

So my situation has evolved slightly and I will now now be getting a lightning conductor for a 10m antenna as per my post - https://communities.theiet.org/discussions/viewtopic/1037/26122


Would appreciate any feedback on relevance of my SPD to the installation. Should I be making a TT island for the ametur radio unit (like a ham) connected to the antenna and putting the TT island behind a Type 1 SPD?

FaeLLe:

AJJewsbury:

[2] Broken PEN has been something I was paranoid about so I got an ABB device that monitors earth and neutral breaks, I think it is called RC223.

Basically have it to protect the outdoor EV charging point to comply with 18th edition amendment 1; did not want to have someone wandering around touch the car when it is wet and get electrocuted.

Broken PENs are nasty things - not only is there the shock hazard from things that should be earthed, but there's the general issue of anything up to 400+ volts appearing between L & N - which tends to do permanent damage to a lot of equipment. SPD don't help much in that event either - they can only really deal with very short pulses of over voltages - not something that might last for hours or days.

This is why I got the Earth Neutral break monitoring device to disconnect power supply to my EV if there is a break in neutral.

I also considered converting the PME supply to something like TT with an earth rod but then decided that I did not have the resources to maintain the seperate earth connection infrastructure!

The electricity substation is less than 12 feet from my distribution box! So less chances of someone digging the street up between me and the LV board..

I know the regs say it is based on risk assessment but what does that really involve?

Just plugging numbers into a formula and see if you get an answer above or below 1000. The numbers come from whether your situation is rural/suburban or urban, lightning flash density your location (the regs supply a map for the UK), and the features of the last 1km of the network that supplies you (whether underground or overhead and how much of that 1km is HV or LV). I can dig out the details if you're interested.

Hi Andy I would be interested to read up and learn a bit more on this if you can point me to some documentation.


Also keen to understand what my lightning flash density is as I have now installed outdoor WiFi access points all around my land but conveniantly ignored the advise to get a lightnight surge protection device fitted in line with the Ethernet cable.


   - Andy.

 

 

So my situation has evolved slightly and I will now now be getting a lightning conductor for a 10m antenna as per my post - https://communities.theiet.org/discussions/viewtopic/1037/26122


Would appreciate any feedback on relevance of my SPD to the installation. Should I be making a TT island for the ametur radio unit (like a ham) connected to the antenna and putting the TT island behind a Type 1 SPD?