What is meant with "MAINS supply cord" in the EN61010-1 ? - Page 1
Forum section: electronics / projects

author: Sarah
author_rank: Newbie
timestamp: May 05, 2020, 08:16:33 pm
content: Hi folks,i'm a bit stuck with the EN61010-1 and the term "MAINS supply cord" in my usecase.I have a box which's doing some stuff and a solar module that powers this box. Both are connected via a fixed cable (user has no access to any terminals) and are bolted to a carrier. The maximum voltage from the module is about 20V, so i'm waay below the limits described in 6.3.1 and 6.3.2.Now I'm stuck with chapter 6.10 and the definition of "MAINS supply cord". Does my cable between box and solar module count as "Mains supply cord"?In my opinion the whole thing (box + cable + module) is one piece of equipment (and i can skip this chapter) but I'm not 100% sure about this.:-) Sarah

author: TomS_
author_rank: Frequent Contributor
timestamp: May 05, 2020, 09:12:22 pm
content: Can you show a screenshot or copy/paste the text that is unclear?Mains tends to be the 1x0/2x0v AC electricity supply. I don't think I've ever heard it used to refer to anything else.

author: Sarah
author_rank: Newbie
timestamp: May 05, 2020, 10:03:04 pm
content: That's the paragraph.So, "Box <-> Solar panel" and Umax = 20V.

author: themadhippy
author_rank: Super Contributor
timestamp: May 05, 2020, 10:26:45 pm
content: Is there a list of definitions at the start of the standard?

author: Sarah
author_rank: Newbie
timestamp: May 05, 2020, 11:30:38 pm
content: Sort of."3.5.4:MAINSlow-voltage electricity supply system to which the equipment concerned is designed to be connected for the purpose of powering the equipment."On one hand i see the panel as kinda mains, but on the other hand it's a sub-part of the whole mechanical unit.:-) Sarah

author: TimNJ
author_rank: Super Contributor
timestamp: May 07, 2020, 09:18:35 pm
content: Well. I don't have a precise answer, but mains can be a low voltage, and can also be DC. Generally, I'd say the biggest requirement of a "mains supply" is a low source impedance, meaning, there's a lot of available energy behind it. That's usually why safety standards are so concerned with mains circuits. 220V from a high impedance source won't kill you, but 220V from a 100KVA distribution transformer definitely can.It's not totally clear to me (either) what constitutes mains and what is not.However, you may want to take a look at IEC62368-1 and check whether your solar supply circuit meets the ES1/PS1 limits for voltage and touch current. I would detach the solar panel from the system and run it standalone. Just taking a guess, but apply a really bright light source(??) and measure the touch current? The requirements are 60VDC (max) and 2mA (max) through a 2K resistor tied from one wire to earth. Now that I'm writing it, I can't imagine that your panel has remotely enough parasitic resistance back to earth to get anywhere close to 2mA.But my point is, if you can justify that your supply system is compliant with IEC62368-1 ES1/PS1 then it can't be considered mains.

author: themadhippy
author_rank: Super Contributor
timestamp: May 07, 2020, 09:32:08 pm
content: QuoteAnd the definition of low voltage?Quote20V isn't low voltage according to the EN definitions,they call it extra low voltage,so it isn't mains

author: TimNJ
author_rank: Super Contributor
timestamp: May 07, 2020, 09:52:42 pm
content: From IEC61010-1, here it's talking about how to determine appropriate mains spacing. You can see for voltages between 12.5 and 48V, they are saying to comply with the 50V spacing requirements.Again, it's not 100% concrete, but they are definitely saying a supply between 12.5 and 48V is mains, even though its technically less than the SELV requirements.

author: TomS_
author_rank: Frequent Contributor
timestamp: May 07, 2020, 10:07:25 pm
content: Well, IEC60320 are your typical "jug/kettle" power cables, the kind you find powering your PC, monitor, servers, some network devices, electronics test kit etc.So I think in this case mains definitely refers to your utility electricity supply.I've also heard of this referred to as low voltage. E.g. in the streets around my parents house the electrical distribution pillars are referred to as "low voltage pillars".In many years gone past when I had an ISDN telephone service, the -48V supply from the exchange which came over there copper pair was referred to as SELV, with the ELV bit standing for "extra low voltage".

author: Neilm
author_rank: Super Contributor
timestamp: May 09, 2020, 04:42:53 pm
content: Please note that everything I am putting in this reply is my interpretation (putting that in as I do know people on that committee)I have enboldened the part in your quote that contains your answerQuote from: Sarah on May 05, 2020, 11:30:38 pmFrom what you have said your box connects to a solar panel that is supplying your power. This panel is part of the equipment that you are suppling.The mains as referred to in the standard is anexternalsupply system for getting power into your unit - generally an AC source. For the purposes of how I understand you are making the connection to the panel would be part of the system you are designing.If you are in doubt ask yourself a question - if you did touch any of the conductive bits would you get hurt? If they shorted, would they start a fire? Are you liable to get a transient on the connections if it came disconnected while curent flows? If you do, would it contain enough energy to be a short hazard (as defined in section 6, there are couple of nice graphs that show the hazard levels although the hazard levels have been reduced in amendment 1)From that you should at a minimum be able to construct a technical argument to justify what you are doing.Also, remember that as far as you know I am just some shmuck on the internet and there are a lot of people out there who will give advice that is not necessarily any good. Fortunatley this forum is generally free of those and when they do appear they get corrected by more knowledgable people. However if you are still concerned then you can seek advice from a notified body or test house.

author: Sarah
author_rank: Newbie
timestamp: May 20, 2020, 10:59:36 pm
content: Guys,thanks for Your input. Going along the standard I came to the conclusion that my 20W panel does not count as mains. The voltage level and impedance are way to low for the standard to cause any hazard, the panel is mounted to one unit together with the device itself and has a fixed wiring. Nothing can be done by an operator, it's sort of an 'inert' device which's just put somewhere where it does it's thing.:-) Sarah

author: elektrolitr
author_rank: Contributor
timestamp: May 21, 2020, 10:10:09 am
content: Quote from: TomS_ on May 07, 2020, 10:07:25 pmIn an electric power world, everything below 1000VAC is considered "low voltage" (not to be misinterpreted as "safe voltage", it's just higher is even more dangerous)Then, usually (but not always, depending on country), 1kV<v<100kV is "medium voltage" and everything above 100kV is "high voltage".