how safe is 60VAC?

[grifftech]

I purchased a 240 to 120volt stepdown transformer and replaced the input cord to convert it to a 120 to 60 volt unit. How safe is this voltage? It is not isolated, also what can I use it for.

[Monkeh]

As safe as the person using it.

If you don't know what you can use it for, why did you buy it and rewire it?

[BillB]

If you don't know what you can use it for, why did you buy it and rewire it?

Since when does that matter?   

[grifftech]

As safe as the person using it.

If you don't know what you can use it for, why did you buy it and rewire it?

mostly to run incandecent bulbs dim, with no interferance

[helius]

As far as touch-safety, earth-referenced 60VAC is obviously safer than 120VAC, but not actually safe in situations where the user may be casually exposed.
https://en.wikipedia.org/wiki/Extra-low_voltage describes the limit for touch-safety to be 50VAC to earth or any other circuit.

[Gyro]

Yes comes under ELV - Probably SELV depending on the quality of the transformer.

Remember though that 'safe' also includes current capability, you can still start a fire with 60VAC just as easily (probably easier) than you can with mains.

[calexanian]

The non isolated part is more of a concern. you will feel 60 volts if you are in a relatively low impedance state (Skin moisture content elevated)

[Monkeh]

Yes comes under ELV - Probably SELV depending on the quality of the transformer.

Remember though that 'safe' also includes current capability, you can still start a fire with 60VAC just as easily (probably easier) than you can with mains.

Err - no, 60VAC is not ELV.

[Gyro]

Err - no, 60VAC is not ELV.

Damn, yes you're right, sorry. I can't remember what happens if you have a groundable secondary center tap available - similar to building site 55-0-55V.

[Benta]

"It is not isolated"... meaning that depending on how you plug it in, you might have 120 V (to ground) on the output. Not safe at all.

[Monkeh]

Err - no, 60VAC is not ELV.

Damn, yes you're right, sorry. I can't remember what happens if you have a groundable secondary center tap available - similar to building site 55-0-55V.

That's RLV which is a UK specific thing. It's basically treated as LV with a reduced risk which looks good on the paperwork for building sites.

[Gyro]

Sure, I was just wondering if you could [Edit: achieve SELV] with 30-0-30. Depends on the transformer of course.

[Monkeh]

Sure, I was just wondering if you could achieve a 30-0-30. Depends on the transformer of course.

Sure. But that's still LV, not ELV. Voltage between any two conductors in the circuit or any conductor and ground.

[Gyro]

"It is not isolated"... meaning that depending on how you plug it in, you might have 120 V (to ground) on the output. Not safe at all.

I completely missed the "it's not isolated" in the OP  - No, it's a non starter!

[grifftech]

I meant that it is grounded

[Brumby]

So - just clarifying - the primary and secondary are fully isolated from each other and the case/body is grounded ... right?

[Zero999]

As far as touch-safety, earth-referenced 60VAC is obviously safer than 120VAC, but not actually safe in situations where the user may be casually exposed.
https://en.wikipedia.org/wiki/Extra-low_voltage describes the limit for touch-safety to be 50VAC to earth or any other circuit.

That doesn't mean that it's fine to build a device with 50VAC on live parts, uninsulated from the user.

The touch voltage of 50VAC on exposed conductive surfaces, is what's acceptable under fault conditions, not normal operation.

The user still needs to be insulated from 50VAC or 120VDC and below, by at least basic insulation. The voltage has to be below 25VAC (EU), 30VAC (US) or 60VDC, before the circuit no longer requires insulation from the user. This is only true for dry conditions: damp areas have even lower voltage limits, before basic insulation from the user is no longer required.

[Yellofriend]

"Deadly" starts at 50mA and 60VAC can qualify for that.

So in the ol' days in Germany they wanted to set the deadly voltage at 60V, but raised to to 62V because German Telekom (then still state owned) used 60V for their phone network and that would have meant all the wiring to the enduser would have to be up to VDE standard. That 60V only applied while ringing though. No idea how it is nowadays.

[Red Squirrel]

Depending on skin condition. I was once shocked by 36V AC. I was also knocked out by 90V AC (from telephone ringing signal) once. Those were when my skin was sweaty. When my skin is dry, I think I can handle 60V AC easily.

Felt that many times.    It's a really weird low frequency AC feel. 

[Horusaem]

Some ppl can withstand higher currents and voltages that would kill the "table" person , but such tables are maid to ensure that the product is safe for everyones use  . To go offtopic one of my teachers that had some Soviet background ( for real he was russian ) could withstand a 220 ( back than ) Volt from the main but his hands were dry as a diamond .
 
Transformers are always dangrous things , if you`ll be unlucky in touching those at the moment you didn`t chose the situation might be fatal. It`s not the voltage that kills but the current or more likely how it messes muscle tension around in your body . One of the things I was told a thousand times was to never grab unsealed wires and when I do I beter use my right hand only. As hear is on left if the current goes from the hand to the leg you`ll be shocked but might live with a valuable lesson if it goes from right hand to the left hand the shortest way is throygh the chest and via heart muscle and that would be end of the class for you

Use CAT III or Burn Baby

PS: We used to make a Legend that that teacher would drink so much vodka in his youth that the voltage is his body was higher than the mains voltage and the electric company should pay him for giving away free energy when he touched mains line  ( loses a little in translation but I hope you get the joke )

[jmelson]

Depending on skin condition. I was once shocked by 36V AC. I was also knocked out by 90V AC (from telephone ringing signal) once. Those were when my skin was sweaty. When my skin is dry, I think I can handle 60V AC easily.

I grabbed a PC board with through hole connectors on it once.  It only had 12 V DC available.  I got a pretty "shocking" shock from something that I thought couldn't possibly do that.  The tail of one of the connector pins must have pierced my skin enough to contact the live layer beneath.  It never bled, so must have just reached the live tissue.

Jon

[GlennSprigg]

"Deadly" starts at 50mA and 60VAC can qualify for that.......

'Yellofriend'....  You are not quite right mate.  Yes, people generally forget that it is not
the Voltage that kills you, but the Current !  Someone may have wet fingers, and be standing
on a wet floor in bare feet, in circuit with say 60/80/90 Volts and receive a lethal dose! through
the heart, resulting in uncorrected Ventricular fibrillation. 

 Someone else way be in a relatively 'dry' environment, and have very dry skin, and not be adversely
affected by 'brushing' their fingers or hand (hands) over 'those' voltages, or even 110-V (in the U.S.),
and/or in my case even 240-V (in Australia).  Yes... we feel it !!!!!........

(NOTE:  I've been an Industrial Electrician, and Special Class Technician for 40 years, and I know what
I am doing, and do NOT expect others to copy what is/was standard practice to me !).

(BACK to CURRENT for now...)
Generally these days, we have power switchboards that rely on either 'ELCBS', or 'RCDs'....
(Earth Leakage Circuit Breakers, and Residual Current Devices/Detectors).
VERY ROUGHLY, (and many types work in many ways!!!), they can detect an imbalance in the
current flow in the Active & Neutral, and 'surmise' that the 'extra' is flowing through YOU, if you
touch something 'live', and you are in some way or partially 'Earthed'.....

Now USUALLY these devices are set to 'Trip', between 25mA & 30mA, and can do so in a small
fraction of a second!   AT THAT current, and above, you may be killed....  However, if you have
an isolating 'transformer', especially where neither output wires are 'REF'd' to Neutral/Earth, then
it may not protect you !   (This subject is too big to explain simply....... sigh....)

Then we can get into 'Auto-Transformers' where there is no elect isolation from Primary to Sec.
And the 'Centre-Tapped' Secondary windings which throw a whole 'nother curve ball......
Basically..... 36V should never be anything to worry about.....

B.T.W.  Just for interest !!!!!
You have a BETTER chance of surviving an 8,000V or 10,000V shock, for 1 or 2 seconds, than
a 240v shock for say 3 to 5 seconds !!!     Why?.....
Lower voltages can leave the heart in that state I mentioned, being "Ventricular Fibrillation".
This is a useless 'quivering' action by the heart, leading to death, without using a "Defibrillator" !
Very HIGH voltages, although leading to physical BURNS, (and subsequent death if prolonged),
initially cause the Heart to electro-muscularly clamp so tightly, that it can't get into that State !!
So when the 'shock' is removed, it basically goes back to normal !!!!!     (Survive but burnt  )

[Iwanushka]

No idea about new regulations and the other things that changed but long time ago anything above 24VAC in some conditions was asummed dangerous and in others even deadly.
P.S.  actuality under "right conditions" you can die from 9VDC battery that you have in your dmm, but this one is very rare only know one case of this in my country.

[Red Squirrel]

We have a 48v battery plant at work, 1,600a normal draw, it's capable of much more.  You can touch bus bar and not have issues.  The voltage still needs to be high enough to drive current through you. So voltage does play a big role.

Drop a wrench across the terminals on the other hand.....      Boom.   Even across a single 2v cell would probably be disastrous.  4800ah per cell to give an idea of the size of these. 

[Zero999]

We have a 48v battery plant at work, 1,600a normal draw, it's capable of much more.  You can touch bus bar and not have issues.  The voltage still needs to be high enough to drive current through you. So voltage does play a big role.

Drop a wrench across the terminals on the other hand.....      Boom.   Even across a single 2v cell would probably be disastrous.  4800ah per cell to give an idea of the size of these.

48VDC is less likely to case a shock, than the same AC voltage. The peak voltage of 48VAC is nealry 68V and the mains frequency is more likely to interfere with the nervous system and the rhythm of the heart, than a steady current.

Depending on skin condition. I was once shocked by 36V AC. I was also knocked out by 90V AC (from telephone ringing signal) once. Those were when my skin was sweaty. When my skin is dry, I think I can handle 60V AC easily.

Yes even relatively low AC voltages heart like hell. I've had a similar experience with a transformer outputting 30VAC but with 70VDC I hardly feel anything, at worst a slight sensation when I touch and let go of the conductors, which makes sense: it's the change in current which my nerves respond to, more than when it's steady DC.