New pot build, 220 vs 110

[USMC87]

I need a little input as to voltage for heatbands to use on a self build pot. Should I use 220 or 110 volt? Is one easier to adjust? Just need to see my options and what would best suit my needs. I'm using 5.5 inch outside diameter double wall pipe as a pot and will be using a pid control. Thanks ahead for the help.

[C.F.Plinker]

How many watts will you be drawing? If you are under 1000-1200 watts I would go with 120 volts. From there to 2000 watts you could use either. If the load is over 2000 watts you probably want to go with 240 volts.

If you build it for 240 volts you will probably be limited to using it in locations where there is a 240 volt circuit available. Most houses don't have 240 volts available in the garage or on the patio or back yard. Will you be installing a new circuit where you want it?

[Geppetto]

I've been getting rolling on a design for a home built pot, and decided to go with 220v due to a deal I found on a 1200 W heater. Also going to go with a PID controller. The one thing I ran into is that if you are planning on trying to incorporate any little bells or whistles like a cooling fan for the SSR or a indicator light, or over/under temperature lights, most of the pieces parts I have laying around are 110V lamps and fans, so to use those with the 220v input, I need to run 4 wire (2 hot, neutral and ground) 220v into the controller to get a 110V leg (as I understand it).

If you are just going to run the PID without messing around with other stuff, then all of the above doesn't really matter and you can run a 3 wire (2 hot, ground) 220v into the pot. BTW, all of this is based upon my reading of the various PID posts on this forum, so if I am blatantly incorrect about something, someone please clarify/correct me.

[Frozone]

Simple availability may make your choice for you.

It is far easier to find high wattage bands in 220 volt instead of 110.
Most of the more inexpensive bands you'll find are used in the plastic molding Industry.
There the machines that do the extruding, casting ect. run 220V (or in many cases 440) so that is the band voltage as well.

[boltaction308]

I am building a new pot and went with 220 because I got a good deal on ebay for a couple of heaters. There are more available and at $40 each, they are a good deal.

http://www.ebay.com/itm/IMS-HBA5-ICI65-6-1-2-TO-7-CAPACITY-CERAMIC-HEATER-HEATING-BAND-1650-WATTS-/290742972400?pt=LH_DefaultDomain_0&hash=item43b1a1aff0

They are 440/220 with 3 terminals.

Does anyone know how to wire the 3 terminals for 220. I am guessing the outer 2 get connect together but I am not sure.

Thanks

[wv109323]

I would think that two of the wires are the two "hot" legs of the 220V circuit and the third is the ground or common.

[wv109323]

Back to the original question. There should be no difference in adjusting between the two if they are of equal wattage. As already stated there is the inconvenience of supplying 220V to your casting area if that is your decision. Another thing to consider your existing 110 V circuitry. The 110V will draw twice the amperage as a 220V. You should consider and determine that the existing wiring is adequate for all the load you will have on that circuit.
Also the internal wiring and the supply cord to the pot will need to be sized to the voltage/amperage that you decide to use. Since the amperage of the 110V is twice the amperage of the 220V, the wiring will need to be of the proper(larger) size. That's not a "biggy" but the larger wire will cost more.

[USMC87]

I have both 220 and 110 close to my casting area but did'nt consider any of the other options. I guess it will be decided by which one is available at the build time. Does 220 adjust ok with the pid controller?

[Frozone]

PIDs read temp,and how much it changes. They couldn't care less what the heater voltage is.

[bgoff_ak]

Many of the PIDs are DC requiring a solid state switch to trip the heater bands. So either would work as you can pull dc easily from a rectifier from either 240 / 120 ( or at least the few I have )

[Dale in Louisiana]

Just remember that for a given wattage, a 120 unit is going to require twice the current as a 240-volt unit. Most common household receptacles are going to start having problems after fifteen amps, but that's 1800 watts, in other words, lot of heat.

If you choose to pull a lot of current through a wall outlet, make sure it's a GOOD receptacle. Believe me, there are cheap ones and good ones and they're both available at the same stores. Also make sure that it is wired in correctly. A lot of new construction uses some less than quality techniques. If you don't understand what this means, check with a trusted electrician.

Same goes with checking the receptacle when it's in use. Touch it. If it's warm to the touch, it needs attention. If it takes less of a pull or push on a plug, you have a problem. These things DO wear out. If you look and see signs of heat on the face of the receptacle or the plug you're using, investigate. It usually means something is worn out and needs changing.

The current difference will also make a difference when you're selecting on-off switches and thermostats. Most of them are rated for 250 volts, so voltage isn't a problem, but current might be. This applies to the control relays, too, if you're using a PID controller.

I 'play' with electric heaters all the time in my real job. They're used to keep the insides of high voltage switchgear and motors dry. A common trick we use is to use a 240-volt heater at 120 volts. At the lower voltage they last forever, a big plus for something you don't want to be digging into that NEEDS to keep warm. Of course, at half voltage, you only get a quarter of the heat, so a 1000 watt 240-volt strip will put out 250 watts at 120 volts.

Also remember that at 240 volts it's a lot easier to pump enough current through your tender carcass to produce fatal effects.

dale in Louisiana
(industrial electrical power all the way to 500,000 volts since 1977)

[Vinne]

I am building a new pot and went with 220 because I got a good deal on ebay for a couple of heaters. There are more available and at $40 each, they are a good deal.

http://www.ebay.com/itm/IMS-HBA5-ICI65-6-1-2-TO-7-CAPACITY-CERAMIC-HEATER-HEATING-BAND-1650-WATTS-/290742972400?pt=LH_DefaultDomain_0&hash=item43b1a1aff0

They are 440/220 with 3 terminals.

Does anyone know how to wire the 3 terminals for 220. I am guessing the outer 2 get connect together but I am not sure.

Thanks

You will need an ohm meter to check it. I you get three ohm readings that are the same then there is a change it could have a 220 volt 3 phase heater. Incorrect voltage at that point can damage the heater.

[Mal Paso]

I am building a new pot and went with 220 because I got a good deal on ebay for a couple of heaters. There are more available and at $40 each, they are a good deal.

http://www.ebay.com/itm/IMS-HBA5-ICI65-6-1-2-TO-7-CAPACITY-CERAMIC-HEATER-HEATING-BAND-1650-WATTS-/290742972400?pt=LH_DefaultDomain_0&hash=item43b1a1aff0

They are 440/220 with 3 terminals.

Does anyone know how to wire the 3 terminals for 220. I am guessing the outer 2 get connect together but I am not sure.

Thanks

If it is a 440 heater, to run on 220 the two ends get connected to one line and the Centertap to the other line.

The resistance (Ohms) between the two ends will be twice that between the centertap and either end
.

[Dale in Louisiana]

You will need an ohm meter to check it. I you get three ohm readings that are the same then there is a change it could have a 220 volt 3 phase heater. Incorrect voltage at that point can damage the heater.

Okay folks, three-phase and three terminals are NOT the same thing. Vinne is partially right.

Here's what you do:

Number the terminals 1, 2, 3 or A, B, C or whatever.

Take your ohmmeter and measure the ohmic values between the terminals 1-2, 2-3, and 3-1.

If your readings are, for instance 1-2=10 ohms, 2-3=10 ohms and 3-1=10 ohms, then you have a three-phase heater. Connect one leg of the correct three-phase voltage source to each terminal and you're good to go.

If you get 10 ohms, 10 ohms and 20 ohms, you have single-phase center-tapped heater. Connect rated voltage to the two terminals where you got 20 ohms. On some apparatus, the center terminal may be connected to your neutral conductor.

Additionally, if you have the 10-10-20 single phase heater, you can connect the two 10's together and feed half voltage to the heater between the two connected terminals and the single terminal. Remember, half the resistance, twice the current.

all this is pretty basic stuff to me, but if it's not your game, it can be confusing.

dale in Louisiana

[FLYCUTTER]

Very good on your explanation Dale but one important thing to do before you light this thing up. With the heater grounded check each terminal to ground with your ohm meter, and make sure its fused properly. If its 3 phase use a starter with overloads. Your electrical cord must be sized right for the current draw and use the green wire for grounding to the pot and source of electrical power, otherwise you might light up some day.