I agree with MarkT's assessment up the point that the leakage in not dangerous. While typically that probably true, when around water I believe things get more dangerous.
They don't seem to be too much more expensive and personally the peace of mind is worth a lot more. I would also purchase a supply from a more well known mfg. Keep in mind the danger is really with the failure modes. A medical rated supply is required to have more robust isolation so a failure is very unlikely to cause a safety concern.
You might also need to check your local building codes.
Interesting approach but...
I havent seen anything in the datasheet about medical applications.
Does it have anything to do with one of the standards it complies with ?
I will bet your insurance company will require certified equipment installed by a licensed electrician, and that may require electrical permits and inspections.
I'm definitely not an expert on this subject but I have seen references to "medical grade" power supplies and with a little help from google I found this:
I believe the key points are the AC leakage and the physical layout of the board and parts, with an eye on failure modes.
Regarding local codes, I believe no two are the same. Here in the US the NEC as a basis with local codes modified by some rules that I've never understood.
Also I've never heard of an insurance company denying a claim because the homeowner did their own work. Now lawyers..... that is a different story. Here in the US we are clearly litigation crazy
Watcher:
I am now inclined to raplace the transformer with a higher voltage one, ie 15V instead of 12V and then use a rectifier and a DC-DC back converter.
If it were only that easy. You must choose a transformer with a split bobbin to insure the windings are separate. A layered constructed transformer could short internally and connect the mains to the output.
Simply google "split bobbin transformer" and you will see numerous examples and offerings. Again, for my pool I would choose a name brand transformer.
I realize this is probably frustrating for you, a seemingly simple task turns complex but I'm sure its worth the extra effort.
You must choose a transformer with a split bobbin to insure the windings are separate. A layered constructed transformer could short internally and connect the mains to the output.
Yea..good point there.
Interestingly, the existing 12v transformer, installed by the original pool company, is not a split bobbin one!
Slightly off-topic but if your house has either 100mA or 300mA RCD protection then it effectively offers no personal protection against electrocution. These currents are far more than required to cause fatality.
jackrae:
Slightly off-topic but if your house has either 100mA or 300mA RCD protection then it effectively offers no personal protection against electrocution. These currents are far more than required to cause fatality.
True if these currents were to pass from the body. The 300mA RCD value is calculated based on the touch voltage which corresponds to around 50v if i am not mistaken.
Any use ? The problem will be that any third party inspection is going to look for approved equipment not home made , so he doesn’t have assess it and create personal liability for himself. ( inCourt -“why did you approve this “ A “ it’s marked as suitable and meeting approved standards”
Verses.. A” I considered it was safe “
Which is followed by “ I see , what is your experience with x,y,z..are you qualified in designing ABC .”)
Same would apply to yourself , if you kill anyone ... you are responsible for the design and test of whatever you put in, and need to have the correct ( provable ) expertise . There may also be an issue giving advice on forums on such matters , unsure.
Any use ? The problem will be that any third party inspection is going to look for approved equipment not home made
The curious thing about this topic is I could not find any information that would suggest what that approval might consist of. Suppose the installation used a Medical Grade power supply (or any power supply for that matter) which was UL, CE, etc approved; would that be considered "approved equipment".
The little research I did on this topic (NEC 2012 and UL 676) concentrated on bonding of metal parts and use of GFI / RCD devices.
Also the OP mentioned the original lighting (hopefully "approved") did not even have a split bobbin transformer.
jackrae:
Slightly off-topic but if your house has either 100mA or 300mA RCD protection then it effectively offers no personal protection against electrocution. These currents are far more than required to cause fatality.
Why would anyone install a 300mA RCD ?
My shed, built by me, was wired to the then current UK 'regulations' (not actually legal requirements) which specified 30mA RCDs. That was maybe 20 years ago.
Many years ago, I was manager of a video arcade. When the power supplies failed, we replaced them with generic switch mode power supplies.
However, I found out that without grounding, just the leakage from parasitic capacitance in the power supply was enough so that the chassis would float at 1/2 of the line voltage, 60V here, and with enough current to give you a palpable shock. I discovered this by touching the chassis of two games, one with a broken ground lug on the cord, the other properly grounded.
My shed, built by me, was wired to the then current UK 'regulations' (not actually legal requirements) which specified 30mA RCDs. That was maybe 20 years ago.
Maybe a "repossessed" one from an industrial site/employer in the mistaken belief that they were enhancing their home safety. That said, the original poster did state the RCDs in question were 100mA and 300mA.