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Safe electrics?

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DaOld Man:
A lot of areas in the UK (United Kingdom, not University of Kentucky, sorry Wildcat fans!), use 220 volts on the appliances. If this is the case, then it is perfectly ok to swap the two mains leads. (But keep the ground straight).
Also, be sure your PC power supply is switched to 220 volts on the little red switch close to the power plug.
That is, of course, if your system is in fact 220 volts.
If you are not 100% sure, look at the labels on some of your kitchen appliances (small apps, IE toaster), see if they require 220 volts.

Also, 3KW is more than enough to sufficiently kill you. It only takes around 50 MA. (Just to give you an eye opener, 50 MA at 120 volts is around 6 watts, at 220 volts it is around 11 watts. 3KW is 3000 watts.)
So be careful, unplug your cab before doing any work inside.

One more edit, my first statement about the two 220 volt wires being interchangeable on UK systems may not be true. If one of the phases is grounded (as we do one of our 120 wires), then one of the 220 volt mains will be "neutral" to ground. If that is the case then the two phases are not interchangeable.
Its always best to call a qualified local electrician or the power company to find out for sure.

MonMotha:

--- Quote from: lilshawn on November 15, 2012, 06:56:15 pm ---okay, it seems everything there is "double insulated"

--- End quote ---

They're either double insulated (a "Class II" appliance), or they have a conductive chassis which is grounded ("Earthed" in Europe - this would be a "Class I" appliance).

In fact, the only time live and neutral really matters is with old "Class 0" equipment where some exposed element of the circuit, such as the return shield on an audio connector, is directly attached to the AC line or where sufficient measures are not taken to prevent this from occurring in typical fault scenarios.  The classic example is an old radio where no transformer was used - things such as tube heaters were just strung together and placed directly on the AC line or a guitar amp that, either by design or due to trivial fault, references its circuitry directly to one of the utility lines.  Not exactly the safest design, and designs like this have generally been prohibited for sale for quite some time in most countries.  In this case, it is important that the neutral be the exposed reference since it's the only thing generally "touch safe".  Modern designs would use "safety ground" aka "protective earth" for this purpose and only use the AC neutral for returning actual power current.  Polarized outlets are somewhat of a legacy from an earlier era in electrical safety that stick around mostly for backward compatibility.  Lamp sockets in the USA still use the safety features, but do not strictly rely on them.

As a fun little tidbit, if you want to place a capacitor from neutral to ground (e.g. for EMI filtering), despite the fact that this should be a near-zero voltage difference, you actually have to buy special "Y rated" safety capacitors.  If you want to place a capacitor from an isolated low voltage system ("SELV" in standards parlance) like that commonly found on a laptop supply to pretty much anything coming out of the wall (there are various reasons for this), you again need to use Y-rated safety capacitors, but you have to either put two of them in series or get a special "Y2-rated" one that will preserve that isolation.

In general, if you have a system that preserves the difference between live and neutral, you should preserve it during any modifications you make.  Your building codes also probably require that be done in the building wiring if you have any means of polarizing plugs (i.e. plugs that can only be fitted one way).  Check your local building and electrical codes, of course.  If a system shipped with a non-polarizing plug, then it's probably OK to disregard live/neutral differences (assuming it was shipped with the right plug!).

wcndave:
Thought wildcats was Arizona...

In the UK we use 220/230/240 v as it is variously labelled based on the method of measurement.  but all plugs only go in one way.  apart from shavers probably.  I am using all UK plugged equipment.

but I am now IN Italy, and here ALL plugs (domestic) are symmetrical, and therefore the lines must be interchangeable.

I didn't want to get into a huge debate, obviously there are significant differences that mean one should not mess around between countries thinking they know how it all works...

I don't turn off my cab, in the same way that i don't turn off my computer to plug in a USB device.  I guess that warning comes from the decased CRT screens that many "hard core" arcaders use.  I just have a computer with speakers and LCD screen, so working in cabinet is safe as working at my desk ;-)

yotsuya:

--- Quote from: wcndave on November 16, 2012, 01:15:22 pm ---Thought wildcats was Arizona...

--- End quote ---

They are. ---fudgesicle--- the Wildcats!

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