15:51 Oct 27, 2011 

Found this presentation, might be of use, slide 28 explains it in a little more detail:
http://www.slideshare.net/saulsalas/3-electrico-presentation

I would maybe be more inclined to use break instead of open, as in circuit breaker, if you know what I mean. Just a thought ;)

15:45 Oct 27, 2011 

Hi, I'd definitely use voltage, we translate a lot of electrical installations type texts here in my office and tensión is pretty much always translated as voltage. MV, medium voltage, is media tensión in Spanish. Hope that helps a little ;)

14:34 Oct 27, 2011 

Why don´t you post your suggestion as an answer? :)

14:10 Oct 27, 2011 

Well, I looked up 'fuentes de tensión' in the Proz glossary and that was a suggestion given, and then I checked the term in Google and it seems to be viable. I don´t really know anything about this particular area but it's just a small part of a larger text I'm translating.

13:56 Oct 27, 2011 

Looks good to me. Voltage or tension are both ok. Just out of interest why did you go for voltage?

13:32 Oct 27, 2011 

Thanks Matt.
For 'fuentes de tensión' I'm considering using 'voltage sources' so your suggestion would fit in as follows: "Open all voltage sources by means of a visible break switch / visible load-break switch...."?

12:07 Oct 27, 2011 

... in full view, so you can see that the tension is cut before any intervention.