Sharing Knowledge, a little situation I encountered

[apprentice87]

Easy peasy,,

Metal framed tank, metal plate floor, metal chair, bond the lot together, end of problems!!!

[Joke] !!!!!!!!!!

john.

 

[NozSpark]

Transformer isolated supply??

 

[apprentice87]

Being sensible though, are all these pumps and heaters approved for use in fish tanks where people will stick their feet!!!!

I doubt VERY much that there would be a british standard for such frivolities, but presumably the stuff is not supposed to be used in this way. There is a bit in the regs about all equipment has to be suitable for the environment in which it is to be employed etc. Did the makers intend that their stuff would be used for this purpose?? If they did not, then i would certainly not be using it...

john..

 

[Sidewinder]

Sellers,

I can advise you more, but you would not like my fees mate.

I have not seen the install, I have no readings, I have no design calcs, I have no makers data, how can I advise you further?

You could be looking at IT supplies.

You could be looking at faulty kit from new, or by going defective.

You could be looking at a multitude of other situations.

I would suggest a read through 710 first.

 

[sellers]

I cannot advise on the pumps, as I did not install them nor the tanks. 710 is medical locations,

702.410.3.4.1 states that only SELV not exceeding 12vAC, or 30V ripple free DC, may be used. So it may be worth getting these tank installers back to install the correct equipment.

 

[Graham Lister]

Sellers,I can advise you more, but you would not like my fees mate.

Strange response for a forum where people tend to try and give advice. Will have to remember that line.

 

[Sidewinder]

Strange response for a forum where people tend to try and give advice. Will have to remember that line.

I forgot the smiley Graham!

If you read the post I did go on to try and suggest things, and I'm about to go on further.

It seems to me that, quite often these days you post to have a pop at me, do you have a problem with me?

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Sellers,

Yes 710, IS medical locations.

If the install was after 1/1/12 then this would apply.

If it is before then the requirements were only guidance.

You could equally apply the requirements of 702 by all means.

However, are the customers not undergoing cosmetic treatment?

I would suggest so, in which case it could be regarded as cosmetic surgery, thus 710 will apply.

How much actual leakage current is there?

You should be able to get this easily by clamping your additional earth.

It may need some communications with more than the manufacturer, I would suggest an enquiry with the ESC is in order, or at least your scam registrar, perhaps even Trading Standards.

If these units are this leaky after such a short time, or were they so when new?

Is it individual cumulative?

Which device is causing the leakage?

What will they be like in a few more weeks/months/years?

One would hope that your additional bond will keep the voltage down, however, one could loose the means of earthing, etc. etc.

How is the TN-S earth connected?

What is the Ze & the R2's on the circuits & bonding?

Remember that 30mA can kill!

As you have been called in as the competent person, I would suggest you take a long hard look at what is going on and prepare a detailed engineering report to your client as this could be a lethal situation.

 

[Steve3948]

As there are 12 sockets I assume its 12 tanks, so which tank had the 70V, shut it down and refer back to installer.

If it was across all 12 tanks, it's hard to imagine all the pumps or heaters have the same fault but possible.

Do the tanks have water feeds to them for top up or anything linking them all.

I must say the earth rod in each tank don't sound too good, under certain conditions could this not introduce a voltage.

 

[m4tty]

I badly wanna see a picture of this. Did you get any pix Tom?

 

[kme]

I had the "fish nibbling the feet" procedure.

But is was a sodding great tank (think its called a "sea"?) :slap

And it didn`t have a rod in it, as far as I could see.

sellers - me no like. Unless the kit is specifically designed for this purpose - and I think I may have specified a much lower leakage value for any residual current device - if RCDs are in fact the best solution to use, which I have doubts about too.

I`m with the slithery one on this..........dependant on situation, it may be an EDN scenario, TBH.

 

[wozz]

My feelings, you have done a installation all required by customer and installers of other equipment. From what i read thats about as far as you can go. Equipment is installed after no issues were raised by installers, so we assume all good as far as manuf instructions go. There is then a problem with the equipment installed, I think id be contacting the installers of the equipment before I go changing my install.

 

[remustered]

Learners thought... jacuzi, ponds etc all use electric pumps and people in close proximity...isn't the subject already protected for by manufacturers "fit for purpose" equipment.....???

 

[Sonor]

I think id be contacting the installers of the equipment before I go changing my install.

Had a similar problem with fish tanks. When the staff were putting their hands into a few of the tanks to do cleaning or catch fish, they were getting a little "tickle". They would lean on the metal framework which was earthed holding the glass tanks and put their hands in the water. It wasn't tripping the RCBO's. We spoke to the tank supplier and they said that the sump at the bottom occasionally leaked. As it was their equipment they came back and earthed it.