240V Residential Circuit into 347 Baseboard Heater

No!

This might be possible, but some rewiring and/or redesign of the safety and resistance factor of the elements might be necessary....a qualified electrician could make it work but it might cost more than just buying a new heater designed for the voltage present....then again it might be a simple fix...it all depends on the design of the heater...

http://electrical-engineering-portal.com/resistive-heating-explained-in-details

Thanks. i will look at the configeration and see what it looks like.

What exactly is a "347 Baseboard Heater" Do you mean a baseboard heater designed for operation from 347 Volts? (That seems to be what all the other posts have assumed) I've not come across 347 Volts as a standard voltage, but of course there are lots of places I haven't visited.

Or is this a heater with two elements in a 3, 4 ratio to give a total of 7?

Or is 347 a model number?

Or something else?

More specific information will usually lead to a more appropriate answer.

347 Volts is common for baseboard heaters. Don't ask me why.

I think the rating is 277-347V, among other more common voltages.

Thanks. All of my industrial experience has been with 480 Volt systems or lower. 347 V* √3 = 601 V, so one leg of a 600 V 3Ø system to neutral would produce that voltage.

In Canada 600Y/347 V is a common three phase voltage. It is very common for 347 V to be used for lighting in large industrial facilities and for baseboard heaters in large apartment buildings.

Thanks! Obviously I had not experienced that system... Now I know!

Yes it will work but at about half power.

While I ignore you most of the time (ignorance is bliss) I'm with you on this one.

Nof60 has a point about nameplate information and money grabbing insurance companies and their lawyers.

Follow the instructions that came with it.

If in doubt, consult a qualified Electrician. Make sure the installation is documented for domestic insurance reasons.

I'm curious to know what bona fide safety issue would occur from running a heater at less than rated voltage.

Of course, lawyers and insurance companies can readily confabulate phony issues.

And also, of course, motors are different, because subnormal voltage can lead to overcurrent.

If there are any safety mechanisms in the heater and they require the full voltage to trip, it may not trip if there is some sort of electrical fault.

Tornado... I did not say there was a safety issue, only a possible legal one. As an inspector I would have to fail this installation unless the unit had a slash voltage rating of 347/240 V.

I agree with your comment.

When I was a General building Contractor, I would not short cut anything and if the electrical baseboard specified 347 VAC then I would feed it 347 VAC not 220 VAC or 240 VAC because I know the inspector would most likely red tag that item and possibly shut me down until it was rectified and the proper voltage applied!

Also, if there was an issue with the heater and it fried or caused a fire, I'm not going to put my company or insurance on the line for a rookie short cut!

Phew just what I was going to write saved me the time and typing so GA :-)

Resistance heating is just about the resistance. There is no "347V heater" except that the RATING of watts and resultant BTUs of heat is based on applying 347V. You can apply any voltage to is BELOW that value, as long as you accept that it will NOT produce the same amount of heat. Ohm's Law: P (watts) = V²/R . So if you have a heater rated for 1000W at 347V, that means R = V²/P, so 120.409 ohms. If you reduce the voltage to 240V, R is still 120.409ohms, so then P = 487.37w. That's the "roughly half" mentioned earlier.

There is absolutely NOTHING unsafe about this, it is done ALL THE TIME. One major reason in the heating element world is to reduce the watt density of a heater element, meaning if I have an element that must fit in a specific spot, but puts out too much heat and will scorch the product being heated, I use a higher voltage rating on the heater so that the watts / square inch is lower and thereby the surface temperature is lower. The watts and total heat is lower as well of course, so it takes longer for the product to heat up, but it doesn't scorch it. Pasteurizing milk is a prime example of this..

Whether right or wrong... the electrical safety system in place in North America (at least in Canada and the USA), consists of 3 parts.

1) The installation codes...

2) The product standards...

3) The 3rd party product certifiers...

The premise is that when, equipment that is certified to the correct product standard by a registered and qualified 3rd party certifier is installed by a trained and qualified installer to the adopted installation code, an inherently safe installation is the result.

This system has served NA very well for many many years and is IMHO the best system for regulating electrical safety in the world. When one component of the three is missing... all bets are off.

Doing less than this enters into the realm of risk management.