Standy generator control panel issues

[Navaraj]

Control panel attached to the standby diesel generator gets frequently damage despite of earthing of the body and separate grounding of the generator.What might be the causes to damage the control panel of the generator frequently during lightning sound and light rain condition?
only backup generator are effected like control panel issues only .

 

[marconi]

Navaraj: Hello. Your first message is interesting. But to help the Electricians' Forum will need more description by you of the problem, drawings, details of the generator and panel and some photographs of the installation.

 

[Strima]

Any surge protection installed?

 

[Navaraj]

Any surge protection installed?

Navaraj: Hello. Your first message is interesting. But to help the Electricians' Forum will need more description by you of the problem, drawings, details of the generator and panel and some photographs of the installation.

I shall send you details after i reached to site

 

[Strima]

This is what the OP sent me:

Surge protection device (SPD) is installed at the main utility side.My concern is why only AMF controller panel gets damage during lightning and light rain?
i have attached the picture of the installed SPD.



And my response:

Those look like type 2 surge protectors, at the main incoming supply should be type 1. The manufacturer might be able to provide replacement modules that do both type 1 & 2 in one unit.

Might also be worth looking at installing a type 3 at the AMF. There's some options to choose from here: https://www.dehn.co.uk/en-gb/surge-protection-for-power-supply-systems/type-3-surge-arresters

I'll also post this on the main forum as it may help others.

 

[pc1966]

Are there any external control cables to the generator, such as those from an ATS?
If so some appropriately rated SPD on them would help!

 

[marconi]

Navaraj: Could you provide a detailed diagram which shows grounding, bonding and position of surge protection similar to this one:

https://cpower.com/PDF/InfoSheets/44.pdf

Is your installation 'separately derived' or 'non-separately derived' with regards to the neutral neutral?

Is the utility supply overhead from strung overhead bare wires between poles or are the wires insulated and combined into a cable?

 

[Navaraj]

Generator is separately driven system with separate neutral earthing system. I I shall provide you some photos of generator AMF panel. 
[automerge]1584454030[/automerge]

Navaraj: Could you provide a detailed diagram which shows grounding, bonding and position of surge protection similar to this one:

https://cpower.com/PDF/InfoSheets/44.pdf

Is your installation 'separately derived' or 'non-separately derived' with regards to the neutral neutral?

Is the utility supply overhead from strung overhead bare wires between poles or are the wires insulated and combined into a cable?

View attachment 56398

View attachment 56399

The installation of SPD at the main supply

 

[marconi]

What is the line to line voltage of the three phase supply?

Is any surge suppression fitted to the generator supply? If there is please provide a drawing or some pictures.

Some pictures of the changeover switch between utility and generator too please.

Which component in the AMF controller panel is being damaged by lightning?

Last - for now - please post some pictures of the earth/ground electrode(s) - what kind of soil?

 

[marconi]

Sorry, I forgot to ask you what is the type of earthing system used on the utility supply?

Earthing system - Wikipedia - https://en.wikipedia.org/wiki/Earthing_system

 

[Navaraj]

The line to line voaltge is around 389volt.The surge protection is not used in the standy generator.amf controller damage during lightning condition ,i couldnit identify the damage ,display doesnot work and geneeator doesnot start
Both rod earthing and copper plate earthing is carried out which have an average value of 30- 60ohm per earthing , the soil here present at the side is rocky and soil are not favourable.
Will you please suggest the best earthing ,its type for the worst soil conditon where lightning occur more freqently .
At the main utility site ,transformer neutral earthing is done separately

 

[marconi]

I will have a think today and get back to you.


M

 

[marconi]

Are your earth electrodes dry - by which I mean simply put into the ground and the original soil and rocks tamped around them? Or has chemical earthing been used which improves the conductivity of the region immediately surrounding the rod or above and below the plates. In Nepal can you buy Bentonite or Marconite ? See:

Marconite | Earthing Compound | Marconite Supplier | Earthing Systems - https://www.powerandcables.com/marconite/

Bentonite | Bentonite, Earthing | AN Wallis - https://www.an-wallis.co.uk/products/earthing/bentonite/bentonite

Are you able to tell me how the utility supply is earthed? TT, TNCS, TNS as explained in the wiki I sent you a link to? I need this information to advise on the Continuous Operating Voltage Uc of the surge suppressors; at the moment they have a Uc of 335V for the Line to Neutral SPs and 260V for the N to PEN.

If Uc = Us the the line to line voltage and one added a safety factor of 10% then Uc would be 1.01 x 389 = 392V which indicates the Uc of the current 'red' SPs is too low at 335V. But until you tell me the earthing system I cannot be more precise.

 

[marconi]

As I said I have been thinking on your problem so more questions for you.

Do you have a transfer switch to connect the installation between utility supply and generator supply? Is it manual or automatic?

What are the approximate lengths of cables - perhaps you could provide a one-line layout drawing which shows the electrical items and the cabling between them. This is relevant because for a short interconnection one surge suppressor could be effective but for a longer length - which can pick up lightning pulses like an antenna - a surge suppressor at each end of the interconnection is probably required.

Similarly all the earth/ground/bonding need to be short and have a high surface area - a low surge impedance; otherwise they present a high impedance to short high intensity lightning pulses which means they are less effective at conducting short-lived high currents to ground and thereby reducing overvoltages occurring at places in the installation where there are sensitive electrical components.

Does the building itself have lightning protection installed?

 

[marconi]

From where does the Control Panel obtain its 'Aux 8-35V dc' supply?

 

[Navaraj]

As I said I have been thinking on your problem so more questions for you.

Do you have a transfer switch to connect the installation between utility supply and generator supply? Is it manual or automatic?

What are the approximate lengths of cables - perhaps you could provide a one-line layout drawing which shows the electrical items and the cabling between them. This is relevant because for a short interconnection one surge suppressor could be effective but for a longer length - which can pick up lightning pulses like an antenna - a surge suppressor at each end of the interconnection is probably required.

Similarly all the earth/ground/bonding need to be short and have a high surface area - a low surge impedance; otherwise they present a high impedance to short high intensity lightning pulses which means they are less effective at conducting short-lived high currents to ground and thereby reducing overvoltages occurring at places in the installation where there are sensitive electrical components.

Does the building itself have lightning protection installed?

4 pole manual change over switch is present with type 2 spd conncetion and then 3 phase and a neutral of length(35m) is then connected to volatge stabilizer,stabilizer output is connected to standby generator ( generator has contactors which are not damage so far ) then its output is then connected to online UPS (three phase in and single phase out )
Volatge stabiliser and ups are grounded too
But problem is that only generator control panel and stabiliser display panel get damage which do not pass the line ,generator do not self start) and during normal lightning ,main utility line is cut off from manual change over and generator is operated under lightning condition ) and normal lightning ,generator was operating smoothly for three days lightning .after heavy lightning which was high enough to shake earth structure ( as per source ) ,control panel was badly burnt .(generator works perfectly great after controller replacement)
If possible , will you please send me your email id ?
[automerge]1584597466[/automerge]

As I said I have been thinking on your problem so more questions for you.

Do you have a transfer switch to connect the installation between utility supply and generator supply? Is it manual or automatic?

What are the approximate lengths of cables - perhaps you could provide a one-line layout drawing which shows the electrical items and the cabling between them. This is relevant because for a short interconnection one surge suppressor could be effective but for a longer length - which can pick up lightning pulses like an antenna - a surge suppressor at each end of the interconnection is probably required.

Similarly all the earth/ground/bonding need to be short and have a high surface area - a low surge impedance; otherwise they present a high impedance to short high intensity lightning pulses which means they are less effective at conducting short-lived high currents to ground and thereby reducing overvoltages occurring at places in the installation where there are sensitive electrical components.

Does the building itself have lightning protection installed?

4 pole manual change over switch is present with type 2 spd conncetion and then 3 phase and a neutral of length(35m) is then connected to volatge stabilizer,stabilizer output is connected to standby generator ( generator has contactors which are not damage so far ) then its output is then connected to online UPS (three phase in and single phase out )
Volatge stabiliser and ups are grounded too
But problem is that only generator control panel and stabiliser display panel get damage which do not pass the line ,generator do not self start) and during normal lightning ,main utility line is cut off from manual change over and generator is operated under lightning condition ) and normal lightning ,generator was operating smoothly for three days lightning .after heavy lightning which was high enough to shake earth structure ( as per source ) ,control panel was badly burnt .(generator works perfectly great after controller replacement)
If possible , will you please send me your email id ?
[automerge]1584597468[/automerge]

As I said I have been thinking on your problem so more questions for you.

Do you have a transfer switch to connect the installation between utility supply and generator supply? Is it manual or automatic?

What are the approximate lengths of cables - perhaps you could provide a one-line layout drawing which shows the electrical items and the cabling between them. This is relevant because for a short interconnection one surge suppressor could be effective but for a longer length - which can pick up lightning pulses like an antenna - a surge suppressor at each end of the interconnection is probably required.

Similarly all the earth/ground/bonding need to be short and have a high surface area - a low surge impedance; otherwise they present a high impedance to short high intensity lightning pulses which means they are less effective at conducting short-lived high currents to ground and thereby reducing overvoltages occurring at places in the installation where there are sensitive electrical components.

Does the building itself have lightning protection installed?

4 pole manual change over switch is present with type 2 spd conncetion and then 3 phase and a neutral of length(35m) is then connected to volatge stabilizer,stabilizer output is connected to standby generator ( generator has contactors which are not damage so far ) then its output is then connected to online UPS (three phase in and single phase out )
Volatge stabiliser and ups are grounded too
But problem is that only generator control panel and stabiliser display panel get damage which do not pass the line ,generator do not self start) and during normal lightning ,main utility line is cut off from manual change over and generator is operated under lightning condition ) and normal lightning ,generator was operating smoothly for three days lightning .after heavy lightning which was high enough to shake earth structure ( as per source ) ,control panel was badly burnt .(generator works perfectly great after controller replacement)
If possible , will you please send me your email id ?

 

[marconi]

I have sent you in a private message an email address for me.

In your post #8, the third picture shows a bunch of wires. What was the damage and was it all internal to the bunch or did arcing occur to surrounding metalwork?

Does the generator control panel share the same low voltage dc supply as the voltage stabiliser (whose panel also fails)?

From where does the dc power supply for the generator control panel come from? Is it a battery which is trickle charged by a mains battery charger?
[automerge]1584601837[/automerge]
Is the 35m cable a steel wire armoured cable?

Is it practical to co-locate all the electrical equipment (ie Generator,Stabiliser, UPS, COS) inside an earthed metal shielded container (Faraday cage)?

I am researching low voltage dc lightning/surge suppressor technology for the Aux Power supply and sensor inputs.
[automerge]1584602902[/automerge]
https://library.e.abb.com/public/ec...se Electronic systems protection brochure.pdf

Please take a look at the link and turn to page 7/12. This is a nice diagram which shows the way to protect sensitive electronic/electrical equipment from lightning. Could you compare your installation to it and report back to me please?

My thinking at the moment is along the lines that at the moment everything is too dispersed, your grounding is inadequate and not single point, cable lengths are too long and thus acting as antennae, and some simple low voltage dc surge suppression is missing from the power and sensor inputs to the AMF controller.

 

[marconi]

Navaraj: I am in contact with a company in Sheffield, United Kingdom which supplies circuit protection products from the CIRPROTEC range to the telecommunications and energy industries to avoid damage from lightning surges in low voltage applications.

Cirprotec · Protection contre la foudre et les surtensions - http://www.cirprotec.com/

Do you have a budget to spend money on such items? You would buy them not me. If you have not then it is pointless me investigating further - (apart from keeping me amused )

 

[Navaraj]

Navaraj: I am in contact with a company in Sheffield, United Kingdom which supplies circuit protection products from the CIRPROTEC range to the telecommunications and energy industries to avoid damage from lightning surges in low voltage applications.

Cirprotec · Protection contre la foudre et les surtensions - http://www.cirprotec.com/

Do you have a budget to spend money on such items? You would buy them not me. If you have not then it is pointless me investigating further - (apart from keeping me amused )

Sorry i am not trying to amuse you or waste your time ,i will keep it touch with you ,i have lots of queries to ask you.i will chat you after i got free time.

 

[marconi]

Oh - my sense of humour has misfired - I love these types of problems and understand the challenges of dealing with them and you over the distance between us, the language and different time zones. Please tell me more about your qualifications and experience and fluency in English so I can talk to you in the right way.



M