Maximum Voltage / Current to be deemed hazardous and require electric safety approval

[Jester]

This question is only with respect to electrical safety (shock, fire etc), not FCC or anything else. Assume the device does not contain a battery.

From what I understand products and devices that operate from or generate hazardous voltages or current must comply with the appropriate electrical safety standards for that class of device. So for example a computer that is powered from 120V MAINS must meet the requirements spelled out in the IEC 60950 standard when used in the USA.

Now lets say you develop a device that requires 5Vdc @ 0.1A, that relies on a certified wall-plug adapter as its power source. The maximum voltage present in the device is 5Vdc so there is no apparent shock or electrical safety hazard because of the low voltage. If one were to want to either sell this device to the public or provide it to someone as part of a demonstration or proof of concept device, is there any requirement inspection or approval wise for the electrical safety aspect?

Assuming the answer to the previous question is no, then at what voltage, current or power level does electrical safety approval or inspection become mandatory in the USA?

I have read some links that imply anything over 48Vrms requires safety approval.

Can anyone provide any insight?

Thank you.

 

[barry]

Not sure if this is still true, but it used to be in the US that nothing absolutely HAS to have approval. The purpose of approval is liability protection. So, if someone gets hurt from your product and it has UL approval, that offers you some legal protection; whereas if you didn't have approval you could be presumed to be negligent. (I am not a lawyer).

You've touched on an good point, though. If you purchase a 120VAC-5VDC adapter that is approved, your product that connects to it DOES NOT have to be approved, since it operates at less than 35V (or 48, or whatever it is).

 

[marce]

UL is mandatory I believe and its not just a fine you will get a prison sentence...
**broken link removed**
UK its law and UI believe the same is in the USA...

**broken link removed**

 

[Jester]

marce,

Thanks for the two documents, very concise (much easier to digest than the actual standards).

So it appears that the maximum voltage not requiring approval from an electrical shock hazard perspective is 30Vrms or 60Vdc. Energy, flammability etc. is another issue.

I have also read that the 30Vrms may be reduced to 0V in future versions of the standard, I'm not sure if or when this will occur?

Cheers

 

[clearspark]

Hi just gonna paste a passage I've written before about this. The only mandatory safety testing in the US is for equipment that will be sold into OHSA regulated workplaces.

NRTL
One other aspect you may want to consider is the "NRTL" (National Registered Testing Lab) program in the US which was created by the OHSA (Occupational Health and Safety Administration) to "assure as far as possible every working man and woman in the nation safe and healthful working conditions." It generally applies to the majority of private and federal workplaces in the US. Even if the employer is not mandated to adhere to OHSA rules, they may still choose to purchase only NRTL approved products.
OHSA authority is limited to employers, not manufacturers. There is usually no legal requirement for the manufacturer or distributor of the product to seek NRTL approval (ask an NRTL for confirmation of the requirements for your specific product). However, if the employer (be it a private company workplace, or government facility) requires NRTL approved equipment, then you will limit your sales if the product doesn't have it.
Any product that "utilizes electric energy for electronic, electromechanical, chemical heating, lighting or similar purposes" is classified as "Electric Utilization Equipment" and is subject to the requirements of Subpart S of the Occupational Safety and Health Act (i.e. is destined for a workplace) which requires equipment to be "acceptable" to the Assistant Secretary of Labour. The term "acceptable" is defined in 29 CFR 1910.399, and for most electrical products, that means certification by an NRTL. There are exceptions for custom made equipment, or products which no NRTL will test. The regulations do not specify a low voltage exception, since low voltage products can still pose a safety risk.
A list of product categories requiring NRTL approval can be found here and here. Examples of electrical products that need NRTL approval for use in the workplace are: printers, copiers, desktop computers, telephones, employee alarms, water coolers, Christmas lights, electric heaters, air conditioners, electric generators, surveillance cameras, electrical conduits, conductors and electric motors.
You can find a list of NTRLs here.

Note that safety testing in the EU is different story, because they have the LVD (low voltage directive) and GPSD.