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On 08-Feb-22 2:56 pm, Cydrome Leader wrote:
Sylvia Else <sylvia@email.invalid> wrote:
On 07-Feb-22 5:29 am, Cydrome Leader wrote:
Sylvia Else <sylvia@email.invalid> wrote:
On 03-Feb-22 4:47 pm, Sylvia Else wrote:
I bought this Arduino Relay Board.
https://www.dropbox.com/s/emgdcm33190unse/ArduinoRelayBoard.jpg?dl=0
It\'s about 33mm by 20mm.
The mains contacts are on the left, the control contacts on the right.
What bothers me is the trace from one of the control contacts that runs
across the isolation barrier, near to the mains contacts. It runs to a
diode, from which another traces runs back to the right.
The packaging carries a CE label, but I find it difficult to believe
that this is actually safe.
Sylvia.
I decided to sacrifice the relay itself to examine its construction:
https://www.dropbox.com/s/ly8wlfnkvpl1ea9/c_relay.jpg?dl=0
If the coil wire were to break off its pin there, it could get horribly
close to the mains connected (brass?) plate.
And? The cheapest of relays are cheapy made. If you need safety look up
intrinsically safe relays, and no don\'t then try buy buy fakes ones from
amazon or alibaba.
I salvaged four of these from my dead UPS:
https://au.element14.com/omron/g2r-1-e-12dc/relay-spdt-250vac-30vdc-16a/dp/9949410?st=g2r-1
They\'ve clearly been designed so that there\'s no credible failure mode
that would connect the load to the coil.
Sylvia.
Let me guess, one Omron relay costs the same as 5 chinese house-special relay boards.
I don\'t know about the law where you live, but where I am, products are
required to be safe, and the requirement is not relaxed just because the
product is cheap.
Sylvia.
Yeah, sure. Don\'t worry about those relay boards they\'re completely safe
and meet all safety specs. The law says so, therefor they do.
Not sure what you intend by that. Laws are human creations, and can be
breached. People who breach laws can be punished. It is not a defence to
say that the product was cheap.
Sylvia.
On 08/02/2022 09:44, Phil Allison wrote:
The issue then is whether a dangerous voltage from the MAINS SUPPLY can get across the gap from contacts to the coil.
For this, there are two questions:
Is the coil side wiring supply earthed ?
Can a user be in contact with the coil circuitry with no safely earth ?...
The only way that I can see this relay board could be used in a
compliant product is...
Given that the typical Arduino user won\'t know anything about this, it
is irresponsible to be selling this thing, particularly as it could have
been made safely for about the same cost.
The issue then is whether a dangerous voltage from the MAINS SUPPLY can get across the gap from contacts to the coil.
For this, there are two questions:
Is the coil side wiring supply earthed ?
Can a user be in contact with the coil circuitry with no safely earth ?...
The only way that I can see this relay board could be used in a
compliant product is...
Given that the typical Arduino user won\'t know anything about this, it
is irresponsible to be selling this thing, particularly as it could have
been made safely for about the same cost.
An Arduino is a test-bench bare board, not a consumer product.
The
sale of a \'thing\' which is a disembodied component is not at all consistent
with consumer product marketing, in terms of any safety considerations.
An Arduino is a test-bench bare board, not a consumer product.
** 100% IRRELEVANT !!!
The
sale of a \'thing\' which is a disembodied component is not at all consistent
with consumer product marketing, in terms of any safety considerations.
** ABSURD CRAP !!!
The relay board is being sold as a safety related device !
To SAFELY switch the AC supply ( on / off) from a popular hobby PCB controller.
Every AC rated relay I have ever bought and used could do that job well - isolation from coil pins to the AC carrying conductors is huge.
The one Sylvia \"sacrificed\" is not safe for that job.
An Arduino is a test-bench bare board, not a consumer product.
** 100% IRRELEVANT !!!
Imagination is required; open your mind and use some.
The
sale of a \'thing\' which is a disembodied component is not at all consistent
with consumer product marketing, in terms of any safety considerations.
** ABSURD CRAP !!!
The relay board is being sold as a safety related device !
To SAFELY switch the AC supply ( on / off) from a popular hobby PCB controller.
No, the relays don\'t come attached to any AC supply. That\'s a user decision,