Electrical current flow after a spark

[xeshu]

Hi all,
I have a question regarding the flow of electrical current. I have an inverter or UPS if u will, that has an input and an output. The input comes from the mains supply and the output goes to different rooms powering up fans and lights.

Now here's my query: If there are sparks coming from joints or due to any other reason on the OUTPUT wire, is it possible that DUE to this spark, my ups get busted? Basically, can current flow backwards through the output in the ups circitry and damage it or if there's an output fuse, bust the fuse then?

I am no electrical engineer, so my little knowledge tells me that current flows in a specific direction, not
both ways on the same wire. So if theres a spark in the wire of the output, it should effect the applications attached TO the output wire, and not effect the ups which is generating the out put. Unlike the input, if there's an input surge, natrually it will effect the ups as thats input to it.

Am i Wrong? Try to imagine i am mixing wires in the output to develop the spark, should it effect the ups. In my view, the spark should effect the application attached to output as thats the direction of output, flowing OUTWORDS rather then ups (inwards). Please help! My friend who i am arguing with says otherwise, he is of the opinion that regardless of direction, a spark will cause aulfunction either way. I disagree.

Please clearify! Many Thanks

Xeshu

 

[Doomed]

Depends on what is causing the spark.
If it is an earth fault and the oupput of the ups is not fused then the excessive current draw could damage the unit.
I would be very surprised if the output side is unfused though.
It may be an internal fuse in the UPS that protects the output, or (looking at the UPS under my desk) it may have a trip that needs reseting with a small push button.
(and I bashed my head on my desk to bring you this information)

 

[xeshu]

Hmm now this is interesting to know.....cheers for the info doomed, but I am still a bit confused. Basically what I wanted to know was that any electrical appliance connected from the output of the UPS, if that appliance has a short circut or spark in the wire, could that damage the unit. From your answer, it seems that it could.

Therefor in simple terms, anything that is connected from the OUTPUT can possibly damage the unit. Now I was of the view that since its OUTPUT, that is current flowing outwards, it would be impossible for the current to flow back inwards to cause damage to the UPS. (unless ofcourse i hook the output to the mains in which case it will blow it to kingdom kom hehe).

What makes this even more interesting is that if theres an electrical shortage in my house wireing, technically it could send the current back to the meter and blow the meter fuse? According to my logic, the current flows from the meter and the fuse is their to protect the INPUT, it seems i am incredibly WRONG in my logic.

Okay scratch what i said earlier. I seem to be stuck on the linear flow of current and am thinking logically not intelligently. If you imagine, a straight line with four points.

Point A is where the UPS is. Point B is the wire that goes from the output of the UPS, hooked up to a light. Point C is further from B on the same wire hooked up to a fan. Point D is hooked up to the computer.

Now that we have a linear imaginary diagram, lets say point C generates the spark, according to my knowledge of current flow, the current is flowing from A-B-C-D, so point C has the spark it should further go down to D and blow the fuse of D-Appliance. But you mention the term 'excessive current', it seems that the spark could cause the UPS to believe it needs to output more, hence the output fuse blows. So logically, the current hasnt flown backwards into the output, its just that the UPS had to generate excessive output which made the fuse go bust.

Or should i forget it all and just accept the fact that if point C develops a spark, REGARDLESS if current flow is A-B-C-D, all points to and from point C WILL BE EFFECTED. Am I correct in this notion?

 

[DPG]

In your UPS will be an electronic inverter powered from the standby batteries. This will provide the 240VAC out, and it will have electronic components providing the output. Any voltage spikes on the output line of the UPS could damage these electronic components.

Hope this helps, Daz