Stuck on a underpinning knowledge question!

[rugbylad]

Hello Folks.

Situation is I'm doing the online 2356 and have to do some underpinning knowledge questions, but I feel I may be over thinking this one....

"Why would an induced overvoltage occur and what damage may occur if this happened while working on an un protected computer?"

Now is it as simple as a lightning strike say, or tripped circuit breakers, and that excessive current will severely weaken or destroy the computer...or is it much deeper and complex like my brain is telling me?

Thanks

 

[Richard Burns]

The question as you have written it is very vague and not very easy to answer as "unprotected" could mean an awful lot of things and "induced overvoltage" is also not a likely sort of statement.

The question is asking about overvoltage not current.
It is asking about an induced voltage not an applied voltage so this would be imposed in some way from outside the circuit (which is odd).

I think if you ignore the unprotected and induced parts of the questions then you could reword it to say what damage can be caused by an over voltage on a computer, possibly both to a user and the computer.

 

[Darkwood]

Yes a bit ambiguous question .... an induced voltage as above Mr Burns already says is not a transient bred over-voltage through the power supply but a non related circuit inducing a voltage maybe because it runs in parallel with a unscreened computer data cable etc (Although lightning can induce massive transients on the supply hence the ambiguity of the question) ...this can damage the electronics and render the computer as scrap.... the supply to a computer is usually given a level of protection already from mains transients but can still be damaged with excessive spikes so anti-surge protection is recommended for critical systems as well as UPS set ups.

 

[Silly Sausage]

Some good reading to be had here...
BEAMA Publishes Surge Protection Guide - BEAMA | News

 

[Simonslimline]

Hello Folks.

Situation is I'm doing the online 2356 and have to do some underpinning knowledge questions, but I feel I may be over thinking this one....

"Why would an induced overvoltage occur and what damage may occur if this happened while working on an un protected computer?"

Now is it as simple as a lightning strike say, or tripped circuit breakers, and that excessive current will severely weaken or destroy the computer...or is it much deeper and complex like my brain is telling me?

Thanks

Is this word for word how the question reads?

My advice would be to get access to the trainee forum on here. A few of us have just completed all these units and can help you out a bit.

PM one of the mods on here for access mate.

 

[rugbylad]

Thanks for your replies guys, yeah that's how it's worded, a lot of the questions seem quite vague.
I'll have a gander at the trainee section cheers

 

[amckay]

Induced overvolage sounds like it could be data cable run with power cables (230v) and the voltage has been transfered by magnetic field and the damage caused by it being some it systems work on 12v so fried circuits?
I may be well of the mark tho.
Good luck with 2356 tho, I've yet to start mine mid august

 

[malcolmsanford]

Normally data cable such as Cat 5 would be rated 600v which would allow it to be run with low voltage cables. Have a read of reg 528.1 and it tells you what I wrote and other methods

 

[Darkwood]

Normally data cable such as Cat 5 would be rated 600v which would allow it to be run with low voltage cables. Have a read of reg 528.1 and it tells you what I wrote and other methods

We are discussing induced voltage, this has no reflection on the insulation value between different categories of cables but lack of screening on the Cat 5 getting induced voltages from the adjacent LV cable which can damage the electronics of any data system.... think you are missing the meaning of induction here Malcolm.

 

[amckay]

Normally data cable such as Cat 5 would be rated 600v which would allow it to be run with low voltage cables. Have a read of reg 528.1 and it tells you what I wrote and other methods

We are discussing induced voltage, this has no reflection on the insulation value between different categories of cables but lack of screening on the Cat 5 getting induced voltages from the adjacent LV cable which can damage the electronics of any data system.... think you are missing the meaning of induction here Malcolm.

I think that was my fault in miss interoperating the meaning. But that was the point I was getting too. I didn't realise cat5 was rated so high

 

[malcolmsanford]

I never re answered Dark because I read it that you were thinking along the lines I was and worried about eddies

No Cat cable has a pretty high voltage rating

 

[Leesparkykent]

An induced voltage is caused by electro magnetic induction from switching on or off inductive loads or when Zero crossing circuitry is not used. Induced voltage can be from natural causes as well e.g lightning strikes causing transient pulses in to equipment e.g. Computers. Whilst working on unprotected circuit this could cause shock or personal injury also damage to the computer PCB and circuitry causing un rectifibale damage.

 

[Leesparkykent]

If you are stuck on any more questions, I have the lot

 

[Silly Sausage]

An induced voltage is caused by electro magnetic induction from switching on or off inductive loads or when Zero crossing circuitry is not used. Induced voltage can be from natural causes as well e.g lightning strikes causing transient pulses in to equipment e.g. Computers. Whilst working on unprotected circuit this could cause shock or personal injury also damage to the computer PCB and circuitry causing un rectifibale damage.

Don't forget about capacitive coupling as well!