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urbanfarmer
l'estranger
Registered: 12/22/08
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all-american sterilizers: 120V or 240V?
#14444755 - 05/13/11 10:36 AM (12 years, 8 months ago) |
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Any opinions?
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Cryogenicz
what?


Registered: 07/01/04
Posts: 2,421
Loc: Oregon
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Re: all-american sterilizers: 120V or 240V? [Re: urbanfarmer]
#14445953 - 05/13/11 02:55 PM (12 years, 8 months ago) |
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Depends on what you have.
Do you have more 115v outlets, or 240v outlets?
-Graham
-------------------- www.MycoPath.com Mushroom Spawn, Cultures, Fungi Bags, Casings, Master Grain Jars, Bags for In-vitro, Laboratory supplies, and much more! Mushroom Supplies. Fast Turnaround Times. Great Service. orders@mycopath.com enter code shroomery for 10% off product. www.FungiForum.com
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Doc_T
Random Dude




Registered: 03/06/09
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Loc: Colorado
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Re: all-american sterilizers: 120V or 240V? [Re: Cryogenicz]
#14445972 - 05/13/11 02:59 PM (12 years, 8 months ago) |
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If I had a 240 outlet or could have one installed properly, that would be my choice. But the only one I have isn't near where I PC things.
-------------------- You make it all possible. Doesn't it feel good?
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fungus_tao
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Re: all-american sterilizers: 120V or 240V? [Re: Doc_T]
#14446026 - 05/13/11 03:15 PM (12 years, 8 months ago) |
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I'm perfectly happy with my 120v 75x. I let it warm up while I'm mixing substrates and it gets up to 15psi in less than 30 minutes. I consider it highly efficient.
-------------------- Follow the light The Light is your guide.
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mycoelf
Agent Of Chaos



Registered: 06/26/09
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Loc: hyperspace
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Re: all-american sterilizers: 120V or 240V? [Re: fungus_tao]
#14446081 - 05/13/11 03:27 PM (12 years, 8 months ago) |
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240 is a more efficient way to move power and the transformation between electricity and heat is more efficient, thereby reducing your overhead. If your service box is code it can easily handle the juice. Highly encouraged.
-------------------- Mycoelf Sterility is a process that can be likened unto infinity, which is a long walk, the closer to the end you start before beginning, the more achievable the goal of infinity becomes. Remember, cleanliness in next to goddessness
      
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Mike711
friend


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Re: all-american sterilizers: 120V or 240V? [Re: mycoelf]
#14450589 - 05/14/11 11:05 AM (12 years, 8 months ago) |
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Quote:
mycoelf said: 240 is a more efficient way to move power and the transformation between electricity and heat is more efficient, thereby reducing your overhead. If your service box is code it can easily handle the juice. Highly encouraged.
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RogerRabbit
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Re: all-american sterilizers: 120V or 240V? [Re: Mike711]
#14450970 - 05/14/11 12:12 PM (12 years, 8 months ago) |
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If the elements are the same wattage, the only savings in using 240 volts is less losses due to heat buildup in the power cord. This is because for the same wattage elements, the current is double when used on 120 volts, compared to 240 volts. RR
-------------------- Download Let's Grow Mushrooms semper in excretia sumus solim profundum variat "I've never had a failed experiment. I've only discovered 10,000 methods which do not work." Thomas Edison
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mycoelf
Agent Of Chaos



Registered: 06/26/09
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Re: all-american sterilizers: 120V or 240V? [Re: RogerRabbit]
#14451540 - 05/14/11 02:03 PM (12 years, 8 months ago) |
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in 240 current the negative and positive switch directions 60 times per second, so both sides are both negative and positive 60 time per second, large amounts of power are more efficiently transferred as a result, and when you are transforming power into heat the resistance coil is more effectively run in the 240 V set up, this is why electric water heaters are run on 220/240 V, it is simply more efficient. There is no such thing as a 120 V water heater. Line loss has little consideration in the equation. Goddess help me if we have to get out the charts and graphs.
-------------------- Mycoelf Sterility is a process that can be likened unto infinity, which is a long walk, the closer to the end you start before beginning, the more achievable the goal of infinity becomes. Remember, cleanliness in next to goddessness
      
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RogerRabbit
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Re: all-american sterilizers: 120V or 240V? [Re: mycoelf]
#14451893 - 05/14/11 03:20 PM (12 years, 8 months ago) |
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Then you better get out the charts and graphs, because you're mistaken. It's all about line losses and nothing else. 120V is also 60 hz. There are 120 volt water heaters. Most are 240 volt because it allows for smaller wires for the supply current. A 240 volt water heater at 5kw will pull half the current of a 120 volt 5kw water heater. This allows for much smaller supply wires.
There is no difference in heat exchange capability from the element to the water, based on supply voltage. Industrial water heaters and boilers are often 480 volt, three phase for the same reason-much higher kw loads can be fed with smaller wires and breakers, thus lowering cost. The formula for voltage drop is I2R, thus the higher the current through the same resistance(ie lower voltage), results in much more line losses, which show up as heat in the power cord and plug. This is also the reason power lines operate at such high voltages. The high voltage results in much less current, thus they can run smaller transmission lines. RR
-------------------- Download Let's Grow Mushrooms semper in excretia sumus solim profundum variat "I've never had a failed experiment. I've only discovered 10,000 methods which do not work." Thomas Edison
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urbanfarmer
l'estranger
Registered: 12/22/08
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Re: all-american sterilizers: 120V or 240V? [Re: RogerRabbit]
#14451945 - 05/14/11 03:29 PM (12 years, 8 months ago) |
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Both of you are right -- 120V is one leg of 3-phase, 240V is two legs of it. So the 240V heating element is drawing current off two legs.
The open question is: there's clearly a 2/1 factor in heating speed (by joules transferred, not by delta temp). But is there a *cost* difference -- do I pay more somehow with 120V? Or is it just time to heat up?
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RogerRabbit
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Re: all-american sterilizers: 120V or 240V? [Re: urbanfarmer]
#14452047 - 05/14/11 03:53 PM (12 years, 8 months ago) |
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Quote:
urbanfarmer said: Both of you are right -- 120V is one leg of 3-phase, 240V is two legs of it. So the 240V heating element is drawing current off two legs.
Actually, no. Those old 240V 3 phase delta systems with a 'high leg' are obsolete and I haven't seen one go in for over 30 years. I'm sure that's not the system you have in your house.
The power company runs three phase high voltage down the power line, and then grab two legs of it to reduce to 240 volt. A center tap on the secondary of the transformer is grounded, and this is where the 'neutral' on a 120 volt system is generated.
Quote:
urbanfarmer said:The open question is: there's clearly a 2/1 factor in heating speed (by joules transferred, not by delta temp). But is there a *cost* difference -- do I pay more somehow with 120V? Or is it just time to heat up?
Again, not correct. There is zero increase in heating speed, because both the 240 volt and 120 volt all american elements are rated 1650 watt. The same power is being used regardless of supply voltage. The difference is if you have a 240 volt outlet to use, your power cord won't get as hot, provided they give you the same size cord with a 240 volt unit. With a 120 volt cord, it will get hot, and this heat is wasted electricity, and wasted money. I've already had two of my four AA-75X factory cord caps fail. I replaced them with industrial grade, Hubbel 20 amp male plug ends and they don't get nearly as hot as the factory ones did. RR
-------------------- Download Let's Grow Mushrooms semper in excretia sumus solim profundum variat "I've never had a failed experiment. I've only discovered 10,000 methods which do not work." Thomas Edison
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Qultivator
Fungi Farmer


Registered: 01/11/11
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Re: all-american sterilizers: 120V or 240V? [Re: RogerRabbit]
#14453004 - 05/14/11 06:59 PM (12 years, 8 months ago) |
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This was something I too had to consider when building and wiring my farm. The 120V model of the 75X draws around 13A, but the 240V model only pulls about 7A. As RR said, the wattage for both is exactly the same, so the performance (speed of heating) is the same. However, if the number of amps you are going to be drawing is of concern (say, for example, your sub-panel in your lab only has a 30 amp feeder), then you might decide that the 240V is the way to go.
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