Completed Project How bad would it be if I get electrocuted from a 120V 300W UPS?

Thread Starter

Rahulk70

Joined Dec 16, 2016
498
I recently got an old APC BK300 UPS (Input:120VAC & Output:120VAC 300W) along with many other vintage electronics stuffs. So I tried opening the the UPS completely.I noticed that the battery a 12V 7Ah BB battery SLA was completely dead. Well I kinda added som edistilled water and revived it and it seems to be working fine now after a day of charging with a high power automotive charger and put it back on the UPS after resealing the SLA. I removed the UPS buzzer since it was kinda annoying. Connected the SLA and powered up the UPS and connected a 130V 100W bulb and it was glowing bright.I usually do some power electronics stuffs from mains and having been looking to replace the mains as source with an inverter or UPS(always feared getting electrocuted). So does a UPS has enough juice to kill me like power from mains 110V outlet? Also there are two transformers inside the UPS a really big one and a small one on the circuit board.Which one is the inverter transformer? I've posted some pics below.
Thanks in advance.
 

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MrChips

Joined Oct 2, 2009
20,912
It really doesn't matter because we wouldn't hear about it and wouldn't even get a chance to send condolences to your next of kin.
 

Thread Starter

Rahulk70

Joined Dec 16, 2016
498
It really doesn't matter because we wouldn't hear about it and wouldn't even get a chance to send condolences to your next of kin.
Once accidently touched the output of a small 30W 220V inverter but it did burn my skin there slightly thats all. But this one could be bad I had a feeling.
 

Dodgydave

Joined Jun 22, 2012
9,089
The one that is Yellow is the output transformer, follow the Output sockets to the transformer wires....

Yes you can get a shock from 120V ac, but its the Current that will kill you, if in doubt wear rubber gloves!
 

dl324

Joined Mar 30, 2015
10,533
How bad would it be if I get electrocuted from a 120V 300W UPS?
Electrocution is defined as "injure or kill someone by electric shock". For most people, that would be very bad...
does a UPS has enough juice to kill me like power from mains 110V outlet?
Yes.

If you don't know what you're doing, stay away from line voltage.
 

MaxHeadRoom

Joined Jul 18, 2013
20,454
The recognized standard in N.A. for non-lethal voltage is 55 volts.
Anything above, regulation and safety practices apply.
I did work with one fellow who would place the palm of his hand over 120vac source to see if it was live!
AFAIK he is still with us!
Max.
 

ian field

Joined Oct 27, 2012
6,539
I recently got an old APC BK300 UPS (Input:120VAC & Output:120VAC 300W) along with many other vintage electronics stuffs. So I tried opening the the UPS completely.I noticed that the battery a 12V 7Ah BB battery SLA was completely dead. Well I kinda added som edistilled water and revived it and it seems to be working fine now after a day of charging with a high power automotive charger and put it back on the UPS after resealing the SLA. I removed the UPS buzzer since it was kinda annoying. Connected the SLA and powered up the UPS and connected a 130V 100W bulb and it was glowing bright.I usually do some power electronics stuffs from mains and having been looking to replace the mains as source with an inverter or UPS(always feared getting electrocuted). So does a UPS has enough juice to kill me like power from mains 110V outlet? Also there are two transformers inside the UPS a really big one and a small one on the circuit board.Which one is the inverter transformer? I've posted some pics below.
Thanks in advance.
Its the current that kills, and you only need a few tens of mA to get the job done. The rest depends on having enough voltage to push the current and your skin resistance. If you're sweating or the contact point is a break in the skin - its probably curtains.

In the UK; we have 220V - I've survived a few mains shocks, but plenty of people didn't...........
 

Thread Starter

Rahulk70

Joined Dec 16, 2016
498
The one that is Yellow is the output transformer, follow the Output sockets to the transformer wires....

Yes you can get a shock from 120V ac, but its the Current that will kill you, if in doubt wear rubber gloves!
Yep I'm not going to touch it without rubber gloves after reading all these comments. Also those capacitors might have some surprise if I'm not careful I guess.
 

Thread Starter

Rahulk70

Joined Dec 16, 2016
498
Its the current that kills, and you only need a few tens of mA to get the job done. The rest depends on having enough voltage to push the current and your skin resistance. If you're sweating or the contact point is a break in the skin - its probably curtains.

In the UK; we have 220V - I've survived a few mains shocks, but plenty of people didn't...........
I'm glad you are fine. I too had a few bad experiences with 220V buts its much nasty compared to a 110V outlet. This one is capable of 2.5A at 120V so its bad right?
 

Thread Starter

Rahulk70

Joined Dec 16, 2016
498
The recognized standard in N.A. for non-lethal voltage is 55 volts.
Anything above, regulation and safety practices apply.
I did work with one fellow who would place the palm of his hand over 120vac source to see if it was live!
AFAIK he is still with us!
Max.
Haha. So there is a chance that I might live if I touch the UPS outlet! JK :D
 

ErnieM

Joined Apr 24, 2011
8,040
My Dad worked in the power division for a railroad running 600 VDC at enough current to run a train. Literally. Several trains in fact.

He had a trick to quick check cartridge fuses by tapping the ends with his index and small fingers as his hand flew past it. The moving hand kept the contact brief and his insulated shoes kept him ungrounded. If he felt a tingle the fuse was bad.

I yelled at him for quite a long time when I saw him do this in front of me. I was in my late teens (young enough to know some not all) when this happened.

I do not know if he stopped the practice after our talk.

Treet ALL electric power as if it can kill you and it never will.
 

MaxHeadRoom

Joined Jul 18, 2013
20,454
Seriously?? I've tried that multiple times when I was a kid. Maybe they had a weak heart. You never know what could happen with electricity.
Sounds like it could be an urban myth!;)
From OSWA records, the most severe industrial electrical injuries and death are from flash overs, rather than direct contact.
Max.
 

Thread Starter

Rahulk70

Joined Dec 16, 2016
498
My Dad worked in the power division for a railroad running 600 VDC at enough current to run a train. Literally. Several trains in fact.

He had a trick to quick check cartridge fuses by tapping the ends with his index and small fingers as his hand flew past it. The moving hand kept the contact brief and his insulated shoes kept him ungrounded. If he felt a tingle the fuse was bad.

I yelled at him for quite a long time when I saw him do this in front of me. I was in my late teens (young enough to know some not all) when this happened.

I do not know if he stopped the practice after our talk.

Treet ALL electric power as if it can kill you and it never will.
Once made a high voltage 450V circuit from stepping up DC 12V. Rectified the output and used it to charge a 400VDC cap ,acidentally touched the cap leads. Worst day in my life! It was the worst shock I had ever recieved!:(
 

Thread Starter

Rahulk70

Joined Dec 16, 2016
498
I think the highest one I has was from a Colour CRT HV, ~20/Kv!
This was with the set ON.
Max.
LOL! CRT transformer?? A noob question. Which one do you think is bad : a CRT flyback transformer or a microwave transformer to get electrocuted with? I know death is the end result but still. :D
 

MaxHeadRoom

Joined Jul 18, 2013
20,454
LOL! CRT transformer?? A noob question. Which one do you think is bad : a CRT flyback transformer or a microwave transformer to get electrocuted with? I know death is the end result but still. :D
Basically it is a question of if sufficient current flows through a vital organ, e.g. the 9v battery on the tongue the current only flows across the end of the muscular organ, which is not really a vital one!.:p
Max.
 
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