multiple UPS in series

[Chiropteran]

Take 3 fully charged UPSes (uninterrupted power supply), call them A, B, and C.

Plug A into the wall outlet.

Plug B into one of the protected sockets on A.

Plug C into one of the protected sockets on B.

Plug a light into C and turn it on.

Unplug A from the wall, and plug A into a protected socket on C.



The solution to our energy crisis!




I realize it will stop working when the UPS batteries run out, but how exactly would that occur? Which UPS would switch to battery first, and why? Would it stay on battery until it ran out, or would it switch back off battery because it's getting enough power from the other UPS it is plugged into?

 

[amdhunter]

lol, I've wondered this too, but never tried it.

EDIT: I predict A would go out first since it lost power, then B, then lastly C.

 

[sswingle]

My guess is they would all go crazy, randomly switching back and forth.

 

[Zim Hosein]

Originally posted by: Chiropteran
Take 3 fully charged UPSes (uninterrupted power supply), call them A, B, and C.

Plug A into the wall outlet.

Plug B into one of the protected sockets on A.

Plug C into one of the protected sockets on B.

Plug a light into C and turn it on.

Unplug A from the wall, and plug A into a protected socket on C.

The solution to our energy crisis!

I realize it will stop working when the UPS batteries run out, but how exactly would that occur? Which UPS would switch to battery first, and why? Would it stay on battery until it ran out, or would it switch back off battery because it's getting enough power from the other UPS it is plugged into?

I'm not doing your homework Chiropteran! 😛

 

[SoulAssassin]

Originally posted by: amdhunter
lol, I've wondered this too, but never tried it.

EDIT: I predict A would go out first since it lost power, then B, then lastly C.

This is the obvious solution but as sswingle said they will probably all start going crazy because they're getting dirty power.

 

[Jeff7]

A regular UPS outputs square wave AC, which will cause problems in the filtering circuitry of a UPS or surge suppressor plugged into it. They're meant to pass through a good 60Hz sine wave signal. A square wave would appear to them as very significant noise, and the circuitry could overheat as it tries to filter it.


That matter aside, how would this play out...(assuming some kind of superbly high-quality pure sine-wave UPS units)
The UPS connected to the wall would of course switch to battery power immediately upon sensing that it had lost power.

- B remains powered, thanks to A's battery.
- C and the light remain powered, thanks to the power from A, passing through B.
- Thus far, B, C, and the lamp are oblivious to any problem.
- A is plugged into C.
- A thinks power is restored, and switches back to AC input, which was in fact coming from itself.
- Since A was the source of power in the loop, and it has switched its battery off, the entire loop de-energizes.
- All 3 UPSes switch over to battery power.
- All 3 UPSes sense that power has come back, and switch back to AC.
- Lots of relay clicking commences until the batteries exhaust, with A petering out first, as it was unpowered first, and was powering the other units.
- B dies out next as it was powering both the circuitry of C and the lamp.


Meanwhile, the lamp is all WTF and flashes the hell out of the room for awhile, until it says "Ok, fuck all y'all!" and leaves, hurrying to catch a flight on an airplane waiting on a conveyor belt outside.

 

[Perknose]

Originally posted by: Jeff7
A regular UPS outputs square wave AC, which will cause problems in the filtering circuitry of a UPS or surge suppressor plugged into it. They're meant to pass through a good 60Hz sine wave signal. A square wave would appear to them as very significant noise, and the circuitry could overheat as it tries to filter it.


That matter aside, how would this play out...(assuming some kind of superbly high-quality pure sine-wave UPS units)
The UPS connected to the wall would of course switch to battery power immediately upon sensing that it had lost power.

- B remains powered, thanks to A's battery.
- C and the light remain powered, thanks to the power from A, passing through B.
- Thus far, B, C, and the lamp are oblivious to any problem.
- A is plugged into C.
- A thinks power is restored, and switches back to AC input, which was in fact coming from itself.
- Since A was the source of power in the loop, and it has switched its battery off, the entire loop de-energizes.
- All 3 UPSes switch over to battery power.
- All 3 UPSes sense that power has come back, and switch back to AC.
- Lots of relay clicking commences until the batteries exhaust, with A petering out first, as it was unpowered first, and was powering the other units.
- B dies out next as it was powering both the circuitry of C and the lamp.


Meanwhile, the lamp is all WTF and flashes the hell out of the room for awhile, until it says "Ok, fuck all y'all!" and leaves, hurrying to catch a flight on an airplane waiting on a conveyor belt outside.

:heart: :thumbsup:

 

[Newbian]

I think a black hole would just open up and consume us all.

 

[bobdole369]

Long story short - they eventually discharge each other.