Power supply safety ?

Take your average .5 amp 5v wallwart how safe are they ? i mean would you be happy to leave one plugged in all day 24/7 whilst at work if it was supplying say 3/4 of allowable current all the time and had good ventilation?


Which is a safer option in terms of being less likely to catch fire nimh or nicad or alkalines cells or a wallwart ?

In Canada, electrical products are certified to be safe.
Some extremely poor quality electrical products are not certified and are not safe but are sold in other countries.

In Europe, CE marking should signify electrical safety. See eg https://www.businesslink.gov.uk/bdotg/action/detail?itemId=1084696957&type=RESOURCES

alec_t said:

In Europe, CE marking should signify electrical safety. See eg https://www.businesslink.gov.uk/bdotg/action/detail?itemId=1084696957&type=RESOURCES

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Unfortunately, just as in Canada, the Chinese don't really care about safety standards.

However, any Wallwart 'should' be perfectly safe if used within it's specifications.

....if you can believe the specifications

Nigel Goodwin said:

Unfortunately, just as in Canada, the Chinese don't really care about safety standards.

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What do you mean?
Canada has had CSA (Canadian Standards Association) certifying electrical products for many years. Most products in Canada also have Americal UL certification.
Some cheap poor quality junk that is not certified sneaks in somehow.

My electrical utility company gave away compact fluorescent light bulbs for free so that people who never tried them would buy more. Then our electricity consumption will be less.
Guess what? They were all recalled and replaced because the Chinese manufacturer STOLE the certification number from a competitor so they were never actually certified. There were photos of them dripping flaming plastic.

Even if it was certified safe with a sticker on it would you still trust it wouldn't burn your house down ?

Wall warts on my printer, scanner and my WiFi router. Then we have the phones in the house (3 EA) with wall warts. Can't think of much else off the top but they have been doing just fine for years. Then too, I keep the home owners insurance up to date.

There are likely millions and millions of wall warts out there running 24/7/365 and seldom if ever do I hear of a wall wart being the root cause of a house or business burning down.

Just My Take
Ron

The certification "label" is not a paper sticker. It is part of the housing of the wall-wart.
I have many wall-warts. All except one have the CSA and UL logos on them. They are safe.
The "different one" is Chinese (the charger for a model airplane sold in a store that imports junk) and it gets extremely hot even when it has no load. I betcha it will burn my house down.

I guess the risk would depend too on whether a wall-wart is an SMPS or not. From what I read in the press (a totally reliable info source, of course ) the vast majority of house fires attributed to electrical equipment are the result of overloaded mains adapters or extension cables, or appliances such as clothes driers having an obvious heat source. I don't recall reading about any fire due to a wall-wart.

My furnace had its electric fan motor seize up. It filled the house with smoke and the fire department had a difficult time seeing that it was from the furnace.

Another time my house was filled with smoke when a permanently wired electric heater had its thermostat stick in the ON position.

Hi Guys,

Audioguru, if I send you some herrings maybe you could make some kippers You sure seem to have a bit of a smoke problem. Bet you are on first name terms with the fire guys. Seriously though I just hope none of the fires have caused any real damage or injury to anyone.

Nigel, I agree %100 with you about the Chinese! I deal with a lot of laptops and when people have had a replacement power supply, sometimes an un-named one from China they are often very poorly made and can be quite dangerous.

I have seen cases where they actually melted or set alight, even sometimes when not being plugged in to the laptop. One certain lot I saw came with UK 3 pin mains plugs that were NOT fused and another lot had mains leads that were made from the type of flex usually only found in audio cables, they were made of that fluffy cored carbon fibre like material and I personally saw 2 of them that had broken and arked through the insulation!

So as to the O/P question, is a wall wart safe? Depends who made it and if its abused, usually if it looks and feels well made they are ok. Just have a good luck at them before you bet your life on them!

Al

The wall wart-things on 24/7:

1. printer
2. router
3. Two switches
4. access point
5. repeater
6. Serial server
7. USB hub
8 two antenna amplifiers
9. 4 phones and one base station/ans machine
10. Co2/Methane alarm system
11. Wireless water alarm system
12. Laptop power supply - Nearly 24/7
13. Cell phone charger, even when not connected
14. Timer for electric blanket

Plan
Small Automation Webserver
---Interfaces to X-10, Insteon and UPB
---Will eventually allow control of some stuff via cellphone browser
Wireless DXS Receiver
--- for wireless Doorbell interface
--- for Motion Detector, two wireless push-buttons to interface for water circulator
Power for relay module for the DXS receiver


Intermittent wall wart stuff:
Calculator charger
Cell phone charger
HDMI to Composite video converter

So, that's the current and future plans.

Hell, KISS got me to thinking of the ones I never thought to list. It's amazing how many of the little buggers are running 24/7 in this house I never give any thought to. Many of them running for years just doing their thing. I never give them a thought.

Ron

It's a pity the various manufacturers of kit can't get their act together and introduce a few standards for supplies so that half a dozen or so ratings of wall-wart would do, rather than the myriad that's out there. Less landfill. I've heard rumours that smart mass-market supplies are just round the corner, that can talk to appliances and negotiate the correct voltage/current. Anytime soon?

I heard that rumor too. USB, comes pretty close but everything is proprietary. Nearly 3A is possible out of a USB dedicated charging port courtesy of Apple.

assuming a competent person designed and made them.

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That's the assumption that's being challenged in this thread