minuimum voltage required

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BobChiz

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hello,
we are at a conflict as to the miniuim voltage required for a coffee maker.
it is a curttis commerical unit the name plate says 220 volt @23 amps. we have 204 going to the unit.
my understanding is there is a +or- 10% voltage for the operation of equiptment with a UL lable.
thanks for the help :)
 
I would start by contacting the manufacturer's technical department. We've had a few situations where a specific piece of equipment was marked 240V but the service was 208Y/120V. About half the time, the manufacturer said it would work fine on a 208V circuit; for the other half we had to either find a 208V replacement or specify a small buck/boost transformer. I'm not familiar with specific UL testing requirements; maybe somebody else can chime in on that.
 
BobChiz said:
hello,
we are at a conflict as to the miniuim voltage required for a coffee maker.
it is a curttis commerical unit the name plate says 220 volt @23 amps. we have 204 going to the unit.
my understanding is there is a +or- 10% voltage for the operation of equiptment with a UL lable.
thanks for the help :)
Click to expand...

It is of my opinion that the rating of the coffee maker is based upon 240v. If it is a resistive loan then a lower voltage equates to lower amperes which equates to less heating watts which equates to a coffee makers which heats and makes coffee slower.
Are there any other thoughts in this regard?
 
templdl said:
It is of my opinion that the rating of the coffee maker is based upon 240v. If it is a resistive load then a lower voltage equates to lower amperes which equates to less heating watts which equates to a coffee maker which heats and makes coffee slower.
Are there any other thoughts in this regard?
Click to expand...
:thumbsup:
...............
 
templdl said:
It is of my opinion that the rating of the coffee maker is based upon 240v. If it is a resistive loan then a lower voltage equates to lower amperes which equates to less heating watts which equates to a coffee makers which heats and makes coffee slower.
Are there any other thoughts in this regard?
Click to expand...

Then in your opinion why would the label say 220 volts? Shouldn't the 23 amps be at the voltage indicated on the label and would you also assume that the 23 amps is incorrect?
 
130612-1539 EDT

Relative to the original post my answer for this product would be:
The minimum voltage would be the lowest voltage that would allow the product to perform its intended function, be safe, and not damage or shorten the life of any of the internal components.

The word intended covers many factors. One is how fast the coffee is made.

I ran experiments on a small hot pot, Rival 4071WN. Rated 1000 W 120 V 32 oz.

One quart of tap water, 32 oz, with an initial temperature of 75 F. Full power was applied (117 V 990 W) for 5 minutes to raise the temperature to 200 F. 0.08 kWh. If there were no heat losses the theoretical energy input would be 0.076 kWh. This was continuous excitation.

As an aside the purpose of the experiment was to show the use of a Kill-A-Watt meter. And a comparison of heating the same amount of water in a microwave. The microwave required 0.18 kWh of energy vs 0.08 kWh.

Different experiment. The thermostat was adjusted to maintain the temperature of the 1 quart of water at 180 F. At steady state conditions the average input power was about 100 W. Theoretically if we applied slightly more than 100 W when the water was cold, then ultimately a long time later the temperature would reach 180 F.

As pointed out in previous posts determine from the manufacturer if operation at the lower voltage is OK. Then determine if the customer will be satisfied with slower heating, or does the customer even realize that heating time is a function of voltage?

.
 
infinity said:
Then in your opinion why would the label say 220 volts? Shouldn't the 23 amps be at the voltage indicated on the label and would you also assume that the 23 amps is incorrect?
Click to expand...

Because that is the operating voltage in order to get the optimum performance.
When the resistance stays the same and you decrease the voltage amperes is reduced which reduces the heating watts.
It's really not going to damage the coffee maker but it will reduce its performance which will lengthen the time it takes to brew coffee. The voltage can be reduced to a point where you have a pot that can't even get hot enough to boil water.
 
templdl said:
Because that is the operating voltage in order to get the optimum performance.
When the resistance stays the same and you decrease the voltage amperes is reduced which reduces the heating watts.
It's really not going to damage the coffee maker but it will reduce its performance which will lengthen the time it takes to brew coffee. The voltage can be reduced to a point where you have a pot that can't even get hot enough to boil water.
Click to expand...
Another consideration is if the unit has electronic controls (as it seems almost everything does these days). While the heating element might only lose some efficiency, electronics can get mighty squirrely if the input voltage drops too low.
 
P (watts)= E x I or 220v x 23a = 5060w. By reducing the voltage you will reduce the amperes which will reduce the watts.
Should you want to keep the heating watts the same at the lower voltage you must increase the current. The only what to do that would be to redesign the coffeemaker by reducing its resistance for use with the lower voltage in order to increase the current in order to maintain the heating watts that are required.
 
jumper said:
One could go by this chart:

Click to expand...

Good chart for motors we which are inductive loads and not simply resistive loads as is a coffeemakers are. Motor do work. I order to produce the same amount of work at a lower voltage current will increase in order to produce the same amount of HP. With higher voltage the current decreases. Other motor characteristics also are affected such as starting, pull-up, breakdown torque, etc. The optimum performance is at its nameplate rating.
With a coffeemaker lower voltage equated to very simply less heating watts which means longer heating times.
 
JDBrown said:
Another consideration is if the unit has electronic controls (as it seems almost everything does these days). While the heating element might only lose some efficiency, electronics can get mighty squirrely if the input voltage drops too low.
Click to expand...

That is also a point to consider. It may depend upon if it has a switching powered supply that has the ability to function at a reduced voltage. My guess is that it would have an acceptable operating range as they operate with very little current.
I would opt for the lower voltage not having any affect on the control. Should the voltage be reduced to a point where the coffee maker does not even have the ability to heat water in a reasonable amount of time who cares if the electronic controls take a dump at that point.
Of course all of this is just making a guess. It's good to keep an open mind though.
 
petersonra said:
you already spent more than the $200 cost of putting in a buck boost transformer just talking about trying to avoid doing it.
Click to expand...

And I have a friend that owns a restaurant that bought a 208v 1ph blodget pizza oven that didn't know that he had 240v available. And he wonders why he burns out fan and drive motors. He's spent a lot of money for repair in addition to the Chinese fire drill required to get it repaired as one of their specialties is pizza. I located a couple of buck/boost transformers for $600 to buck the voltage back but in one ear out the other. It will work until the next time he fries a motor and he'll worry about that when that happens again.
Oh well.......
 
templdl said:
It is of my opinion that the rating of the coffee maker is based upon 240v. If it is a resistive loan then a lower voltage equates to lower amperes which equates to less heating watts which equates to a coffee makers which heats and makes coffee slower.
Are there any other thoughts in this regard?
Click to expand...

Other factors will come into play as far as how much or how fast it can make coffee.

Does it heat water as it is brewing or does it use preheated water for brewing - that may be one of biggest factors in quality of the finished product.

Also to consider is incoming water temperature, if it is 50 deg F it will require more input to reach desired temp than if it were 80 deg F regardless of input voltage.

It is not that same heater can not raise the media to a specific temperature as much as can it raise it at a rate that still achieves the desired results? Otherwise the element is not going to see any increased degrading if it only receives 204 volts vs 220 volts, but could degrade faster if rated for 220 volts and you actually input 250.
 
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