Green Coffee Buying Club
Coffee Discussion boards => Hardware & Equipment => Topic started by: 187 on June 04, 2008, 06:18:46 AM
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Last night before I started to roast I noticed that my Kill-A-Watt was showing 117.8V. This is on a very short run of #10 wire direct to the Behmor 1600.This line normally shows 122.6V. I called the electric company this morning and as I suspect the answer was "It's summertime" So all of you that think you have adequate power may all of a sudden have stalled roasts. I see a variac in my future.
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It would be interesting to do a actual bean temp vs. line voltage comparison, to see if a few volts translates into huge temp swings.
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I don't know that anyone has addressed the V vs temp issue but my guess last night was to roast 12ozs instead of 16ozs using the 1 pound P1 setting and I used the full time and only opened the door twice to stretch the 1C to 2C time.
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After the power company told me its summertime they must have had a change of heart and checked to see if there was a problem. Tonights roast gave me the following numbers 127.6V before I started and 124.4V under load. This voltage allowed me to draw 1711Watts under full load with the light on and 643W with only the afterburner and light on. Cooling drew 663W with the light on. At this level the small grid basket didn't make any difference. Anybody think this voltage is going to cause premature failure of anything, especially the motor?
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Time of day plays a huge role in what you have available. Electricty on the scale of power companies cannot be stored, powerplants have limtied capacities of production. that is why the electricity market is a real time commodity game.
relatives in germany trade electricity for Eon. (I don't speak with him much, but he explained this to me once.)
Large manufacturing operations buy contingents of electricity in futures and those contingents are time specific. (at least in europe)
So apart from running manufacturing plants 24/7 for machinery cost efficiency production cycles alter.
Smelting on induction ovens is preferentially done at night when the electricity batches are cheaper.
(porsche does final assembly of the cayenne in leipzig because the shared platform comes from eastern europe, they bought that electricity in such batches. The corporate event on test track had they explaining this to us no-nothings. The timing of manufacturing processes that is.)
Knowing this I can imagine that you might see better line voltage at night? The voltage you see is not directly related to the output of a powerplant, but certainly is related to how much they are giving that grid sector.
Can your module plot historic voltage trends over a day? That would be extremely fun to see.
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On a hot day when everyone is running their AC, my voltage during the day can be as low as 108VAC. In the Fall, at night say when there is very little demand for electricity, it can be 124VAC.
A Variac helps you get a handle on this problem, as long as you get the 15A or 20A version (don't try to be cheap by putting a 20A fuse in the 5A Variac). Sometimes it works, and sometimes you end up spending $$$ in fuses.
Any electric home roaster needs a Variac to get repeatable results IMO, regardless of what the manufacturers say.
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I should start playing w/ my Kill-A-Watt some more and plotting line voltage changes.
But I've never noticed a change in roasting times/temps, and maybe the fluctuation is more damaging to roasters that are more automated and less manual. With my SC/TO's, and their accurate bean mass thermometers, I believe I can modulate heat and adjust for changes.
Again, I'd need to see a measurement to see what the proportional difference is between line voltage and heat output. Having a variac would make that experiment a lot easier.
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The cooling is going to draw that kind of wattage because the 'smoke eliminator' element is burning away too to kill the smoke coming out. otherwise its just the fan and motor running.
I work for a power plant and can tell you that voltages can vary significantly from time of day, temperature, and even in your building depending on what you have on.
I can be supplying 125 volts to your weatherhead, but if your A/C is running, you got the coffee thing cooking, possibly cooking dinner, and maybe even the water heater and washer / dryer... guess what, your voltage house wide is going to be quite low. Nature of the beast there.
The age of the wiring in your house plays a big part, if you have aluminum wire plays a huge and most the times dangerous part....
Also, you plug the thing into a plug which is basically two pieces of brass that are springy together, so it's a pressure contact point, not really a hard contact, like bolted on or wire nutted or something difinitively making good solid contact. Over time that plug can corrode, or the springiness gets weak and the connection is not very good, its loose, voltage loss will happen there.... The kill a watt's I have one for a certain type of..... cooker i use, and the plugs in them are not the very best either, I burnt up more than one kill a watt on a mere thousand watts running through it for a few hours because of the loose springy plug thing. yep voltage loss there, almost 3 volts.
Yes the variac can correct the voltage at the cooker but it does not correct the problem... you get the higher voltage at the cost of extra amps... if your circuit is overloaded, or you have loose contacts causing poor connection and HEAT at that spot, pulling more amps through it is only going to make that problem worse. Before you go this route, please take a look and see if you can see what is causing the low voltage first, and be sure it's not a fault that could potentially turn into a fire.
Aaron
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thats why we need to leave the dark ages of 110V. 220V is ten times better in every way :( 110V is just pathetic.
But I don't think that will ever happen.
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thats why we need to leave the dark ages of 110V. 220V is ten times better in every way :( 110V is just pathetic.
But I don't think that will ever happen.
How true is this? I have been reading all over the net about coffee roasting and voltage issues and It has had me thinking
(A) If I get or make a construction site 220v to 110v break out box and plug it in to my 60A 220v outlet in the garage then I should have a very stable electrical source (at least as stable as Ascholten or his local counterpart can provide at the weather head)
(B) If I get the 220v Behmor roaster when it comes out and plug it into a 220v outlet then that too should beas stable as it gets?!?!
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a 220V power source (a true one), has the capability to deliver more energy than either a 15 ampere or 20A 110V power source. That is about as certain as the fact that displacement in a combustion engine is an irreplacable physical entity.
VIR, ohms law and that.
If energy is what you are after a greater voltage to start with is a deeper breath. That cannot be replaced.
I am not a pro at roasting. Many here know a hell of a lot more on that than me. I think once you get into the bigger league's of roasting you will quickly be able to outdo any electrical source even something like 14-50 or 10-50 will be done around there. That is about the most you get as residential lines.
In commercial you can have IEC lines up to 900 AMP, but then your running a induction smelting ove or a maxipress or something?
I am sure there are many reasons why gas is the preferred energy source on larger scales, but I would not doubt that economcis is one of them.
I run my espresso on 220V and I have to say the difference is night and day. It was a pain in the bottoms to get there, but I do not revert voluntarily.
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I am sure there are many reasons why gas is the preferred energy source on larger scales, but I would not doubt that economcis is one of them.
That's one of the reasons. Generation of electrical power from fossil fuels is roughly 25-40% efficient (and I am being generous); that is, only 25-40% of the heat energy generated by the fuel is converted into electrical energy. That's not even counting transmission losses. Taking electricity and turning it back into heat is economically silly.
Also, gas-fired stoves and roasters allow for more precise control of the applied heat--when the gas is off, there's no more heat addition (though there may continue to be heat added due to the heat in the drum).
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I was just talking about the air popper or the eventual ST/CO
I can't imagine using anything but gas for a roaster bigger than 5lbs... I have a gas stove in my kitchen because the heat response quicker than electric, I suspect that is true in the roasting drum.
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Yeah, your above explanations regarding gas make a lot of sense to me. I also subscribe to gas stoves. That brigns me toa question. I am under the impression that sometimes the residential gas pressure in the U.S. has been sso low for me that the gas stove was a joke (glorified camping stove). This happened to me in my last kitchen. So instead of the "chef d cuisine" bang boom bang experience I had the "wait for it" experience on that one. Are there tiered gas line levels for sfety? Should one assume that was the stove or maybe simply a girlish line?
Regards,
Felix
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Another thought occurs to me with regard to electric roasters; if a roaster has enough 'head-room' and can easily attain more than adequate heat, then voltage drops may be a non-issue.
I'm just thinking out loud, as my SC/TO's haven't given me any apparent slowness or lack of response in the 3? years I've used them. Perhaps roasters like the Behmor that have programmed temp/time don't/can't compensate for voltage drops, and don't have the 'head-room' either.
If a heating element has the ability to get the beans to say 475?, then if a voltage drop limits its potential to say 450?, it's no big deal. But if a heating element can only get beans to 450?, then it may be in trouble when power is lessened.
Thoughts of an unlearned man, but it seems to make sense.
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Another thought occurs to me with regard to electric roasters; if a roaster has enough 'head-room' and can easily attain more than adequate heat, then voltage drops may be a non-issue.
I'm just thinking out loud, as my SC/TO's haven't given me any apparent slowness or lack of response in the 3? years I've used them. Perhaps roasters like the Behmor that have programmed temp/time don't/can't compensate for voltage drops, and don't have the 'head-room' either.
If a heating element has the ability to get the beans to say 475?, then if a voltage drop limits its potential to say 450?, it's no big deal. But if a heating element can only get beans to 450?, then it may be in trouble when power is lessened.
Thoughts of an unlearned man, but it seems to make sense.
For me, the whole voltage issue affects repeatability, not really a roasters ability to get X ounces of beans to Y temp in Z time.
It is clear that a pound is about the max we can properly roast in an electric roaster on a single 120VAC/15A circuit, and that is usually adequate for most home roasters.
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I have been trying to get a great roast from my Behmor since Jan. My voltage is 122, and drops to 117.4 when the heating element kicks on. I think I finally compensated by using 12 oz. on P1 maxed out. Getting just to the edge of 2nd crack, and using all of the allowable time. I am going to install a dedicated outlet for roasting, hopefully that will give me better results.
Your Slow Learning Friend,
Doug
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I have been trying to get a great roast from my Behmor since Jan. My voltage is 122, and drops to 117.4 when the heating element kicks on. I think I finally compensated by using 12 oz. on P1 maxed out. Getting just to the edge of 2nd crack, and using all of the allowable time. I am going to install a dedicated outlet for roasting, hopefully that will give me better results.
Your Slow Learning Friend,
Doug
One word: Variac
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A Watt is a watt is a watt, whether you get it from 110 volts, 150 volts, 120 volts, whatever you call it in your area, or 220 volts.
hell if voltage is the key, using that logic why don't you just forego the stepdown transformer and get a cooker that will roast beans at 4160, or perhaps skip another transformer and do a 33.6K cooker? Aww hell, why not just take it right off the tap and go with a 220KV cooker, don't stand closer than 5 feet though or you might become involved in the cooking process.
The only REAL reason folks use 220 is because of the power needed, not because it's better or cleaner power, it all comes from the same transformer, from the same fusebox in your house. Household wires for 115, are limited to carrying about 15 amps, sure you can get a 115 volt 30 amp circuit put in, but you will pay for that extra copper. It will be stable as hell too.
Generally things at about 1800 - 2000 watts swap over to 220 so there is less current draw through the lines, it's the amps that cause the unwanted heat. Higher voltage = less amps for the watt hence less heat loss... all other things being equal.
why does the usa use 115. Umm good question, it is safer than 220 really... yes it does kill a lot of folks but if you get hit by it by mistake, your chances of getting back up, possibly cursing and walking away are a lot greater than getting swatted by 220, 277 or the likes.. Higher voltage pushes the amps, and the amps are what kills.
For home roasters, your residential 110 volts will work fine with a 110 volt coffee roaster if all else is good. If you get a voltage drop on the 115 you are going to get a bit of a drop on the 220 as well... if the drop is caused by insufficient wire load handling ability then that is a fault with the wiring, NOT with the electricity being supplied. BIG difference there.
Before we go running out to put in brand new dedicated circuits, spend hundreds extra on 240 volt stuff, etc... check that the existing wiring is not the fault. If you live in a 50 year old house with 50 year old wiring, umm guess what... the electrician who puts the 'new' stuff in is probably going to tell you the entire house needs rewiring to conform to code if you want the job done correctly, and might even refuse it....
Instead of 16 ounces of beans, try 14 or 13 ounces, ... sometimes little things are a lot easier and a lot less expensive of a fix.
aaron
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I think the power of a heating element directly describes the amount of energy it can dump into the bean mass. So a roaster starved for power will take LONGER to dump the same energy into the beans and if the rate of energy loss of the bean mass equals the rate of energy dumped in we are at max temp.
So my guess is that the first sign of trouble would be a longer timeframe to get toa usual spot.
I think one LOW COST approach to thisacute problem is to go with a slightly decreased batch size.
Less beans need less energy, so the rate of heat input issue can probably be combated a little bit?
Not a hot solution, obviously also throws of consistency and knowledge that one might have devloped for his roast profile with fixed variables (bean mass weight times and so on).
Lucky for me im such a bloody amateur i sit in front of the gene and twist those knobs by the seat of my pants and some rough road points (total time, end point , 350 and aroudn 1st crack...pretty modest goals)
Felix
PS: idea being that I think we would see a routine take longer before we see a roast stall at a lower temp?
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After the power company told me its summertime they must have had a change of heart and checked to see if there was a problem. Tonights roast gave me the following numbers 127.6V before I started and 124.4V under load. This voltage allowed me to draw 1711Watts under full load with the light on and 643W with only the afterburner and light on. Cooling drew 663W with the light on. At this level the small grid basket didn't make any difference. Anybody think this voltage is going to cause premature failure of anything, especially the motor?
The lowervoltage sounds like it should be within its ratings (they are usually +/- 10%, it will likely make your elements last a bit longer.
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sure a watt is a watt. A watt is just another word for power or energy.
However if you try to draw a large amount of energy from a low voltage line you have terrible inefficiency. That is why long distance lines are high voltage lines and why residential areas have local transformers. (and a similar reason makes AC the more efficient current to send over long distances)
Nonetheless it is not possible to cleanly deliver high wattages out of a 110V outlet. The 20 AMP circuits that arose are a patch covering the fact that 110V is a very low electromotive force. With less force you will always have a horrible time delivering great amounts of power. use thicker wires tolerating greater amperes, you have not solved your problem. You patched it...
You can drink fast through a straw, but you have to suck VERY hard.
Big gulp opening on gatorade bottles are pretty sweet.
(that analogy actually holds very well) all the way to likening the frictional loss of turbulent flow (reynolds nubmer and that) to the heat generated in thinner wires)
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While there are theoretical reasons why 220 is more efficient than 110, in the household it is usually not an issue.
And in fact, pulling 10 amps on 110 or 5 amps on 220, the Electric company will charge you the same since they bill you for Wattage (Killawatt-Hours), not Amps or Volts.
The truth is that 220 is often used so that new wire does not have to be run, since it is max amperage that determines the wire size (independent of voltage as I understand it). This means that the same wire that can handle 110V/15A, can also handle 220V/15A. And I can tell you that an appliance that can run at the latter, can do a lot more heating (or work) than the former.
The reality is that most homeowners in the US don't want to run new wiring, or re-do their breaker box, and so we live with the 110/15 in most cases, though many kitchens now get 110/20 circuits. I have managed to run several 110 espresso machines and roasters without problems on 1970's outlets (and with the help of a Kill-a-Watt & Variac).
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Yes running 220 volt appliances will help with the amp loading on the receptacles, but with that mindset...unfortunately you can't find too many 220 volt toasters, 220 volt can openers etc in the usa. It would be very easy indeed to redo your fuse box to put out 220 volts to each and every of your receptacles but you would also have to replace every 115 volt appliance in your house with a 220 volt one... unless you ran every one through a transformer at the plug... and here is the inefficiency / waste thing again.
Seriously though, if you are that adamant on putting 220 volts in, an electrician can run an isolated receptacle, or convert an old one already there for you fairly easily. It'll be on its own breaker and everything. One thing to keep in mind, if you have a water heater, dryer, stove etc, nearby, those run off 220 volts AC, you might have an easy source to tap into very nearby. If you want to get creative, you an jack a 220 volt receptacle into your stove, on top where the controls are and run your machine that way, it will save having to run an entire new line since the line is already run / and breakered for your stove, howver id install another inline breaker at say 10 amps or whatever you need to be safe. It doesn't have to be a hack job either, you can do this very easily and have it look very neat, and technically it will be very safe too... if you do it properly.
Aaron
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heh,
I did put 220V in my kicthen. That is what some of my things run on. See the pic of my espresso machine under that thread.
You are completely correct that 22oV/15 amps is the same as 110V 15amps in terms of current running. But 110V cannot run 30 Amps. That is the ballpark you need if you actually do want to run the heating elements in both tanks on something with boilers that are around a liter.
(brewtus... cannot actually run both heating elements simultaneously and deliver full wattage to them. Vivaldi in non economy mode has 5 extra ampere's that does not mean both elements now get the same the priority element got in 15 amp mode, it is a compromise maxed out at 20 ampere)
Just take a peak at the differences between the 110V Robur, 220V (3-phase 220V).
Mazzer Robur 110v: 7.5 seconds
Mazzer Robur 220v three phase: 4.5 seconds
The 220V runs at 900W you could draw that from a 110V line, but the picture is more complicated than that.
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heh,
I did put 220V in my kicthen. That is what some of my things run on. See the pic of my espresso machine under that thread.
You are completely correct that 22oV/15 amps is the same as 110V 15amps in terms of current running. But 110V cannot run 30 Amps. That is the ballpark you need if you actually do want to run the heating elements in both tanks on something with boilers that are around a liter.
(brewtus... cannot actually run both heating elements simultaneously and deliver full wattage to them. Vivaldi in non economy mode has 5 extra ampere's that does not mean both elements now get the same the priority element got in 15 amp mode, it is a compromise maxed out at 20 ampere)
Just take a peak at the differences between the 110V Robur, 220V (3-phase 220V).
Mazzer Robur 110v: 7.5 seconds
Mazzer Robur 220v three phase: 4.5 seconds
The 220V runs at 900W you could draw that from a 110V line, but the picture is more complicated than that.
You can install a 120V 30A circuit very easily, just use 10 gage wire.
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heh,
I did put 220V in my kicthen. That is what some of my things run on. See the pic of my espresso machine under that thread.
You are completely correct that 22oV/15 amps is the same as 110V 15amps in terms of current running. But 110V cannot run 30 Amps. That is the ballpark you need if you actually do want to run the heating elements in both tanks on something with boilers that are around a liter.
(brewtus... cannot actually run both heating elements simultaneously and deliver full wattage to them. Vivaldi in non economy mode has 5 extra ampere's that does not mean both elements now get the same the priority element got in 15 amp mode, it is a compromise maxed out at 20 ampere)
Just take a peak at the differences between the 110V Robur, 220V (3-phase 220V).
Mazzer Robur 110v: 7.5 seconds
Mazzer Robur 220v three phase: 4.5 seconds
The 220V runs at 900W you could draw that from a 110V line, but the picture is more complicated than that.
110V and 220V are not the same. Take a motor that pulls 12A 110V, that same motor wired 220V will pull 6A.
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yes you could indeed do that (30amp 110V circuit). However inside the machine the wires would have to be able to withstand the used current at the incoming voltage. That is a bit of a problem :p
Running 30 amp fused circuits and feeding multiple outlets is done pretty often in "special code" installations :p
I just don't know any appliances that need a lot of current that have taken this route. I would guess that some J-things must have that though.
They are running 100V aren't they?
110V and 220V are not the same. Take a motor that pulls 12A 110V, that same motor wired 220V will pull 6A.
That is (((())))
I was going to say that is completely correct, but this morning i thought for a second. Help me out here. V=IR
R= the motor and is a constant?
Now if we up the voltage from 110 to 220 we doubled the electromotive force. The current flow of electrons should also double if resistance stayed the same... not half.
yes, no???
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I (Amps) = E (Volts) / R (Ohms) (resistance of the motor) The resistance of the motor stays constant, double the voltage and you half the Amps.
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The resistance of the motor may necessarily NOT stay constant. You have impedance to play with too, CEMF, other issues, but probably diving deeper than most care to understand or even can. Go ahead and plug your 115 appliance into 220 volts. Ill stand by with the camera because yer gonna let the magic smoke out.
Aaron
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The resistance of the motor may necessarily NOT stay constant. You have impedance to play with too, CEMF, other issues, but probably diving deeper than most care to understand or even can. Go ahead and plug your 115 appliance into 220 volts. Ill stand by with the camera because yer gonna let the magic smoke out.
Aaron
I'm not saying you can run a 115V appliance on 230V, they have to be made to run on either and then generally there is a switch to change it or it has to be wired differently. I was commenting on kwksilvers comment that 110 and 220 were the same and also his comment that you can't have a 110V 30A circuit.
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let's say it stays constant for this purpose. consider it a theoretical exercise. ohm's law V=IR
or the way you stated it: I=E (orV)/ R notice the difference in the formula?
I know that for AC it is V=IZ but lets pretend we are DC the motor is a constant resistor and not some inductor style thingy in AC. because I need simple and dumb. undergrad physics was a looong time ago for me.
I think V= I x R no?
I know that the motor is not a perfect ohmic device and that the relationship is not linear when you go far along and that the heat changes the resistor and that the motor isn't a linear reistor anyways.
But should this resistor not have a direct relationship between current and potential rather than an inverse?
(i.e. if i double voltage from 110 to 220 I expect to have increased current runnign across this resistor NOT decreased it.)
Please feel free to correct me on this. I am no expert at all here, but if I did this wrong then I need to be corrected because I do want to be able to have a clear and correct understanding of basic things like ohm's law.
Felix
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I do want to be able to have a clear and correct understanding of basic things like ohm's law.
Felix...
Ohm's law means a Buddhist choir is near by.
B|Java, non-science major
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quote of the day made by BJ!!!!!!
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let's say it stays constant for this purpose. consider it a theoretical exercise. ohm's law V=IR
or the way you stated it: I=E (orV)/ R notice the difference in the formula?
But should this resistor not have a direct relationship between current and potential rather than an inverse?
(i.e. if i double voltage from 110 to 220 I expect to have increased current runnign across this resistor NOT decreased it.)
Yes Felix, your ohms law is absolutely correct. However, a 110v motor would not be run on 220v. It would be able to be configured for either 110v or 220v. In the 220v configuration, it would draw half the current that it would draw in the 110v configuration.
If you visualize 2 windings, at 110v the windings would be run in parallel, and at 220v the windings would be run in series.
When you first look at that, it seems like you are doubling the resistance, and doubling the voltage, so should have the same amps. But, a motor is not a resistor, and works differently.
assume that the motor is rated for 2200 watts (for simple math). 2200w/220v = 10 amps. 2200w/110v = 20 amps
Hope this helps,
Ray
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the problem here is. we are not worried about the motor... how did that take the lead in this topic.... the worry was the heating element not putting out enough heat to do the job. the motor was working fine unless i missed a post somewhere....
Yes you would think that 110 v 220 v current halves, .. if you have the correct elements yes, but if you put 220 through a 110 element you double the current, and double the watts, and the element goes poof.
Due to the way they are constructed etc... the actual heat / temperature output of most heating elements is NOT linear with voltage... or to put it another way, they have a pretty tight 'band of operation' volt wise where you wont cook them..
we are talking about line drop issues though...... yes if you wiring is good, but you are having voltage drop problems causing you heat transfer issues, 220 volts might solve the problem for you, but it's a pretty expensive fix to a variac if your wiring.. again is good... or just roasting 14 ounces instead of 16 ounces... as an example..
Aaron
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I get your explanation regarding the motor. let us go back to a plain resistor with a constant resistance. I think that makes a heating element. it is justa wire runnign hot on purpose.
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I think your are absolutely correct regarding the variac as the best real world pragmatic fix to the problem we may face.
The whole 220V thing is my theory/ dreamcraft regarding the cause of such woes.
If one has 220V in the kitchen or where it is needed and one has the choice of purchasing the corresponding appliance. We have a no brainer.
We have a gene or a Behmor at home (me=gene). We immediately have your variac as the fastest most efficient way of addressing a direct issue.
Does this put as all in the same opinion pot? I hope i did not shove anything into your motuh that you did not say.
PS: regarding AC motors. There i quickly meet my end. I understand simple DC motor principle and I have read to try to understand AC principles for motors.This was a long time ago when i was worried about heat dump of a pump into a hydraulic circuit. in either case I quickly met my master there. So I am not fit to dissect the details of how resistance of motors behave with variations in AC or DC vs. AC.
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Just for the record, a 110V/20A Variac costs about $125 shipped.
And it can be used on anything: Espresso Machine, Roaster 1, Roaster 2, etc., etc.
We all know you have spent a lot more on silly things like tampers, steaming pitchers, gloves, BBQs, and probably a flux capacitor (you know who you are).
While all this theoretical talk is very interesting, the fix for a home-grade electric roaster is easy (whether you have low voltage, or you just want consistency from roast to roast). It is called a Variac. And yes it has some limits (you could not provide 205 volts from a 110 line at the full 20 amps), yes we know that.
And yes, we know now that 220V is superior to 110V, and in the US 110 is the defacto standard. So you pay an electrician or buy a Variac.
Or do what I am going to do: Put a 880V/100A system in every outlet, and then step down as necessary. Does anyone know where I can get a Blu-Ray player that will accept 880V without blowing up?
>:D >:D >:D
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If you do get a variac, make sure you get one big enough to handle your equipment. It may cost a few bucks more but if you are running say 950 watts in your roaster, don't go with a variac that has a 1000 watt rating. Yes... technically it can take it, but running it at that close to 100 percent of its capacity is not the best method. Also as you boost the volts you will boost the watts you are using as well and can find yourself AT capacity or slightly over, again it can take a little overload but not the best way to do it.
Id get a 1200 watt or 1500 watt as a minimum...in this instance. Besides we all tend to end up upgrading eventually, let your machine grow into your variac and use the extra money youd have to spend on yet another bigger variac for your new rig ---pay for that new rig.
For the DC motor thing, I wont go there, there are actually many different ways to wind DC motors to make them behave differently as well. Series / shunt field/rotor etc etc. Don't feel bad that you don't have the savvy of knowing all this crap, those of us who do, didnt learn it overnight, we have worked with this stuff for years and years. Wasn't trying to insult you or anything, just point out that unfortunately, it's not just a simple thing .. that'd be too easy for us then ;D
Heating elements yes, are technically just resistors, but once you start heating something to the point it is turning colors, it can start getting tempermental at that point about many things. Too much voltage.. not by much, they go pop .... too little... not by much and they are just 'warmers' instead of heaters... touch the thing somewhere and cause a 'cold spot' and it goes crack, followed by pop.... you get the idea..
Heat essentially is caused by current flow, voltage pushes that current, yet higher voltage means less current needed to make that heat.... all this flows through wires... heat is a bad thing with wires.... current flow through wires, in a sense is a bad thing too... the less we can get away with, the better, less voltage drop... due to heating etc etc..so yes 220 would be better on that mindview because it's using less current however in the usa where we live in a 115 world.. this can be problematic.
Our main problems are not necessarily the current the device needs, but dragging that current through the wires to get it from your fuse box TO the coffee cooker...the wires are the problem. so unless you were there when they built your house and demanded 12 gauge or even 10 gauge wiring to all your receptacles.. they probably used 14... because its cheaper, and code let them do it.
Ill shut up and go lay over by my dish now.
Aaron
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Our main problems are not necessarily the current the device needs, but dragging that current through the wires to get it from your fuse box TO the coffee cooker...the wires are the problem. so unless you were there when they built your house and demanded 12 gauge or even 10 gauge wiring to all your receptacles.. they probably used 14... because its cheaper, and code let them do it.
Ill shut up and go lay over by my dish now.
Aaron
I hope I didn't cause some of this 110v 220v debate with my post earlier....
Aaron, correct me if I am wrong.. The 220v 60Amp outlet in my Garage for the ceramic kiln is two 110v lines and one neutral line.. If I were to wire a 110v outlet to each of those 110v lines and the neutral (this is a dramatization, do not try this at home) then plug in my coffee roasting omnibus wont it only draw the amps it needs? and wont that big 60amp line mean I have plenty of headroom even if my line voltage is a little low at the moment? I know it is not as sure as a variac but I presume it would be closer than the 20 amp kitchen outlet that runs everything in the kitchen :)
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Well, technically yes.
Every house is wired for 220.... through a center tapped transformer.... ie its split in two, so if you take one hot leg and the middle leg you get 110...half the entire 220 being sent to you.
The 110 volt loads, by far the most common in any household should ideally be split between both legs... in other words dont drag too much energy off one of the hot legs and ignore the other, it could cause problems..... another common nomenclature for the centertap /halfway point is called the neutral line, which again technically is supposed to be at ground (ie zero)potential... don't depend on tghat, a fault in your wiring will set you on your ass in a second if you automatically assume neutral = ground.
If you have a 60 amp breaker for your kiln and you want to take a bite off one leg, and the other through the neutral / ground and run your coffee pot, well that will work very well. Being 60 amps that wire is very thick probably 6 gauge or thicker, that will easily handle what your roaster / brewer will need any day. You can even hook another one up and tap off the other side of the 220 line into neutral .... and thensome.
What you are saying is pretty much what happens in any house... the 220, they take one line, and return it to the neutral for 115 volts... your setup will work fine.
As for your voltage, you should not have a voltage drop over that setup with your coffee pot, if you do, there is a serious wiring fault, which to be honest, your kiln should have started the fire in your walls long ago with its probably 40 to 50 amp draw... If the power company is giving you low voltage, there is nothing you can do to change that except a variac, which will allow you to boost it.... if your low voltage under load is caused by the wiring, then bigger wiring, as in your 60 amp rating will help..... or again a variac....
also, yes you are absolutely correct, your cooker will only draw what it needs.... the 60 amp rating is pertaining to the MAX amount that wire can safely handle, you can draw UP to 60 amps, and your roaster will draw whatever amps .. the thing you have plugged in needs. if it draws over 60, the circuit breaker will eventually trip.
Aaron