I’m planning on installing a cove heater, those up by the ceiling, so my 8 month old will not burn herself on the current plug-in oil finned one.
Here’s the conflicting info: the electric company says 240 at 4 amps is no cheaper than 120 at 8 amps. The place where I’m going to buy the heater says I’ll use twice as much juice with the 120. Mathematically, they seem the same.
Who’s right?
I’d prefer the 120 as then I don’t have to buy all that 240 wire which is nearly as much as the heater itself for the run I need.
Thanks.
Replies
Watts are watts, as far as the cost of electricity is concerned. If you run the heater at 120v or 240v it will cost the same.
The main advantage of 240v is the heater will draw half the current, and depending on the size of the heater it can save you some money since you can use smaller wire. However, for a heater that small it won't make any difference either way, so you may as well get the 120v one.
I am a little confused by what you said about having to buy all that 240v wire...it doesn't really cost any more to wire a 240v device than a 120v device, unless you mean you can just plug the 120v heater into a nearby existing receptacle.
Likely they are refering to using something like 14/2 for 120V and 14/3 for 240V - a significant cost difference
"Likely they are refering to using something like 14/2 for 120V and 14/3 for 240V - a significant cost difference"Not if they know what they are talking about.14/2 is perfectly fine for use on 240.It only where you need BOTH 120 and 240 that you need the 3rd wire.In home that is almost alwasy only dryers and stoves.A/C, water heaters, and other electrical heaters only use 240.
You are right about needing only 14/2 in this case. However, I can assure you that on water heaters, HVAC equpment on the like, the neutral wire is required in many cases due to the need for 120V control power. Relays in the HVAC and Water heaters require 120. I wasn't thinking that there were no relays with the cove heater. THanks for the correction
Water heaters don't use relays.And A/C relays usually use 24v.
I have wired many heat pumps and never had need for a neutral. Indoor or outdoor units. 6/2, 8/2, 10/2, 12/2, 14/2 have all been used. The only time I ran 10/3 is when I had it on a job site and was out of 10/2. Built in control transformer changes 240 to 24 volts for relays & thermostat circuits. Water heaters get 10/2 even if the current model I'm installing could get by with 12/2, as the heater may be upgraded at a replacement time. Gas furnaces need a neutral, but they are only 120 volts, so only one hot wire.But, some manufacturer could sell a unit that needed a neutral, so always check the wiring diagram just in case....Frank DuVal You can never make something foolproof because fools are so ingenious.
Ok, to reveal the full depths of my ignorance (as if many of you had not already guessed), how do you complete a circuit without a neutral?
You just need two wires. One of them doesn't have to be at ground potential.
Seven blunders of the world that lead to violence: wealth without work, pleasure without conscience, knowledge without character, commerce without morality, science without humanity, worship without sacrifice, politics without principle. --Mahatma Gandhi
The two "hot" legs are the current path.
Each leg is 120 volts to neutral; each leg is "out of phase" or the location of the alternating peaks are essentially opposite allowing current to flow.
Fascinating. I had not thought about the phase difference.
You mean the third plus the ground, right?
"I cut this piece four times and it's still too short."
thanks.12/3 w ground is more that 12/2 with ground
P(watts)= I(current)x E(voltage). It ends up being the same. 240x4 and 120x8 both equal 960 W. If the wiring runs aren't long, the cost difference will be slight but it's up to you, ultimately. The 240 uses 1/2 as much current on each leg but the same total wattage.
Depending on the wattage of the heater you may not need to run a larger gauge wire at all. Is the heater in the room currently on its own circuit? If so you could run up to a 3600 watt 240 volt heater on 14/2.
If the existing heater is on a circuit with other heaters you would need to do some investigating to see what their voltages are and such.
thanks. the existing heater is a "plug-in" so I need to make a new run.