Can a 120 volt item be used in SA?

[adrianh]

Modelling sounds similar to electronics in some respects. I don't have a problem with working with tiny discreet components because I have the appropriate tools, holders, magnifier and lighting, it's just when I have to use my enormous pork sausage fingers direct without tools I sometimes struggle.

Attachment 6479

I designed numerous PCBs and spent many hours with tweezers and magnifying glasses soldering 0805 resistors. I went through a (That pcb should be frigging small (for no real reason) phase.

[Boeriemore]

You HAVE TO buy a suitable transformer otherwise your device will blow up!

That said, suitable transformers are available so it is not really a big deal. I actually have one because one of my printers was only ever manufactured to run on 120V

My power heads are up and running. However, I am concerned that the 120v converter gets hot and I can even smell “burning” heat.
I worry that it can cause a fire so if someone can confirm that this is normal then my mind would be put at ease.

[adrianh]

It will get hot if you are drawing more current than what the convertor is designed for.

[AndyD]

Can you attach a couple of photos of your setup? Power supplies can run quite warm but if it smells like burning that's not a good sign. Same as Adrian I'd suggest you might need a larger more capable power supply.

[Boeriemore]

It will get hot if you are drawing more current than what the convertor is designed for.

Converter is rated at 50w. The power heads are drawing a total of 12w.
I have disconnected one power head and now the converter no longer gets hot, only warm. Strange.

[AndyD]

50Watts might be the input power of the converter, not the output power. If it's no longer overheating with one of the power heads disconnected it's pretty certainly overloaded.

[Boeriemore]

50Watts might be the input power of the converter, not the output power. If it's no longer overheating with one of the power heads disconnected it's pretty certainly overloaded.

Now that is weird. Converter is rated at 50 watt input yet connecting only 12 watts and it is then overloaded?
This just does not make sense. I assume that the fact that the converter's frequency is 50 hz and the power heads are 60 hz is not a factor.

[HR Solutions]

I put up 12v lights(only 6) ....... the ones on two wires that run across the room. I replaced the transformer twice because it overheated and burnt out - I eventually got a big bugger, drilled holes in the box that it is housed in for ventilation and no more problems

[AndyD]

Now that is weird. Converter is rated at 50 watt input yet connecting only 12 watts and it is then overloaded?
This just does not make sense. I assume that the fact that the converter's frequency is 50 hz and the power heads are 60 hz is not a factor.

The numbers can be deceiving unless you know exactly what they refer to.

I've no idea what these things are that you're running but if they have motors in them the 12 watts rating on them may refer to the motor power. Here's the rub, motors are rated by their mechanical output ability, not their electrical power consumption. Small/fractional horsepower motors are notoriously innefficient at the best of times so to do 12watts of mechanical work the motor could easily be consuming double that in electrical power (24watts). You've got 2 motors so there could be nearly 50 watts of electrical power required to run them.

But wait, there's more.... The 50 watt rating of the power supply could be referring to the load it places on the electrical supply (input power) in which case the output power that's available to run your two thingamabobs will be far less. Realistically it's often 20-25% less than the rating stated so you could have a load that's close to 50watts running on a power supply that can only deliver about 37 watts.

It's not unknown for some of the less scrupulous power supply manufacturers to tell blatant lies about the performance of their products, I've come across descrepencies of up to 50% between real life performance and the fairy tale figures given in the product data sheet.

The nature of the load can also be important, often you can get away with overloading a power supply if it's only for a short run period followed by a substantial off period but obviously if your wave thingies are running continuously this won't help. The fact it's a 60 Hz load on a 50Hz supply is also stacking things against you, this could cause them to consume even more power (and run hotter than they were designed to). Motors are also an inductive load which can distort the phase angle of the power supply which causes inefficiencies and losses so that won't help either.

Without a few pictures this is all guesswork but there is a good possibility you're overloading the power supply even though the figures at face value might not suggest so.

[Boeriemore]

The numbers can be deceiving unless you know exactly what they refer to.

I've no idea what these things are that you're running but if they have motors in them the 12 watts rating on them may refer to the motor power. Here's the rub, motors are rated by their mechanical output ability, not their electrical power consumption. Small/fractional horsepower motors are notoriously innefficient at the best of times so to do 12watts of mechanical work the motor could easily be consuming double that in electrical power (24watts). You've got 2 motors so there could be nearly 50 watts of electrical power required to run them.

But wait, there's more.... The 50 watt rating of the power supply could be referring to the load it places on the electrical supply (input power) in which case the output power that's available to run your two thingamabobs will be far less. Realistically it's often 20-25% less than the rating stated so you could have a load that's close to 50watts running on a power supply that can only deliver about 37 watts.

It's not unknown for some of the less scrupulous power supply manufacturers to tell blatant lies about the performance of their products, I've come across descrepencies of up to 50% between real life performance and the fairy tale figures given in the product data sheet.

The nature of the load can also be important, often you can get away with overloading a power supply if it's only for a short run period followed by a substantial off period but obviously if your wave thingies are running continuously this won't help. The fact it's a 60 Hz load on a 50Hz supply is also stacking things against you, this could cause them to consume even more power (and run hotter than they were designed to). Motors are also an inductive load which can distort the phase angle of the power supply which causes inefficiencies and losses so that won't help either.

Without a few pictures this is all guesswork but there is a good possibility you're overloading the power supply even though the figures at face value might not suggest so.

Thank you. Very informative (and technical)
As my camera is faulty all I can do is quote what the converter and the wave maker (power head) states.
Converter: Dowa DW - 50
Step down converter
Input 220v AC 50w 50hz
output 110v AC 60hz

Sunsun JVP-101 wave maker
Voltage 110-120v / 60hz
Power 6w
output 3000 liters per hour.