Aussiedistiller, Home Distilling, Moonshine, Home Brew

Hi Guys

Electricity is not my strong point. I just wired up a watt meter into my boiler heating element. Its a 2400 watt element from 5star. The reading is coming out at 2000 watt. There is a 10 meter extension cord though. Would 400 watt loss be normal or have I wired the meter wrong??

Im not an electrician but I think there is something to do with the "power factor" which can change the wattage and this will change as the element heats up?

I'm sure a learned sparky will be along soon to clear it up :handgestures-thumbupleft:

Firstly, do you know the volts and the amps you are drawing? 240 volts is 2400 watts at 10 amps. However voltage supply can go either way above or below which will affect the watts output.

I routinely get 250 (and sometimes higher) where I live, and I have a solar feed in to the grid with a Fronius Inverter that corroborates the grid voltage I measure, however a higher voltage means a higher watts output.

Having said that, such a voltage drop over the distance you mention seems like a lot. I wouldn't expect it to be that much. Can you test while hooked up to a shorter extension cable / different extension cable / no extension cable and see if there is a difference?

If you can confirm that your voltage is correct, next steps are to check your wiring and the element itself.

Thanks GSX I will check the volts next time I run her. Might get a shorter extension cord and see if it makes a difference

Some of the ads I've read for elements claim that the international standards for elements are allowed to be +5% to -10% of its claimed rating, dunno how true that is, but a combination of that and voltage fluctuations from the grid would easily cover 400w, we don't get a constant 240v, it's often well below that

Have you tried the meter on anything else?

Was the extension cord sitting in the sun? Heat will add a heap of resistance to the cord

10m... is it a white household cord? They can be made of pretty thin wire and shouldn't be used for constant heavy use

Can you try the boiler plugged directly into the socket?

Just a word of warning when using extension leads, NEVER leave them coiled up when using them to power an element as they can easily overheat and catch fire. Today with cheap extension leads made in China are a big worry when drawing 10 amps or more for an extended period of time as heating will occur and the risk of fire is ever greater.

Cheers Bryan

Hi There

The voltage drop along the extension cord will be negligible unless it is very long and very thin.
I would suggest a 15amp cord ( 1.5mm2 cores) minimum.
I would think it is your in-coming voltage.
The electricity net work is supposed to provide 240v +- 5%
I routinely see 221v at my place which is well outside the spec
Are you also using a phase controller (ssr) on the elements as a lot of those will not go to full 100% if you are then a simple bypass on the controller should give you more power.
Does Your watt meter give you voltge and current readings?
If you are using phase controller then the meter needs to be installed before the controller as they do not like a distorted sine wave.
The voltage will then show you incoming voltage and the current flow but will not make sense if you try to work out the power from those measurements only.
It will also depend on where you are connected on the network and the size of your mains cables into the house and if your running in a shed then the size of the feed to the shed.
I have a 50lt keg with 2 x 2400w elements and it will almost always show a max power if 4200w.
Hope this helps.
Cheers
Dave

Dave, if you were trying to work out the efficiency of the ssr, with the watts meter hooked up, would you be able to use either a voltage or amp meter accurately after the ssr to look for differences? Pretty pointless I realize, but I like numbers :smile:

Yes - what is the core size of your extension cord? I hope its at a minimum of 1mm2 (Its written on the cable itself), otherwise I don't recommend using it - safety first.

I've used a 25m 1mm2 extension with a 2400W load and didn't get a power drop like that. I'll admit, that I'm now replacing with a 10m 1.5mm2 (Rated to 15A) for safety and lower power drop (Increase efficiency).

Also - heating elements will draw less when cold, and more as they heat up.

RC Al wrote:Dave, if you were trying to work out the efficiency of the ssr, with the watts meter hooked up, would you be able to use either a voltage or amp meter accurately after the ssr to look for differences? Pretty pointless I realize, but I like numbers :smile:

Yes but you need a special volt meter to measure a chopped sine wave as well.
Even a true rms quality meter will sometimes not measure a voltage output from the phase controller, the same as trying to measure the output from a variable speed drive.
I use fluke 87 mk 5 meters at work.

The watt meter installed before the phase controller will give you a very accurate wattage being consumed but the voltage will not be correct.
The current will be constant throughout the circuit though.
Untill you drop below 50% output from the phase controller you are still feeding a full 240v but not a full sine wave so you get less power.