Water heater element Amperage - Page 2 - Home Brew Forums
Home Brew Forums > Home Brewing Beer > Electric Brewing > Water heater element Amperage

Reply
 
Thread Tools
Old 09-25-2013, 04:43 PM   #11
stlbeer
Senior Member
HBT_SUPPORTER.png
 
stlbeer's Avatar
Recipes 
 
Jan 2008
Fenton, MO
Posts: 970
Liked 38 Times on 37 Posts


Quote:
Originally Posted by k_mcarthur View Post
why in the hell would anyone do that? I use 120v in my setup and I use 2000w, if I could get 2500w more heating power just by running a #10 home run and 30a breaker I would do it all day long.
The primary reason for doing this is to reduce the watt density of the element. Less power per square inch of element surface means lowering the likelihood of scorching the wort. This way you can take a high watt density element that's rater for 220v and run it at 110v and it will effectively be low or ultra low watt density.
__________________
My RIMS eBrewery build

 
Reply With Quote
Old 09-25-2013, 05:34 PM   #12
processhead
Recipes 
 
Oct 2007
Nebraska
Posts: 793
Liked 131 Times on 102 Posts


Quote:
Originally Posted by stlbeer View Post
The primary reason for doing this is to reduce the watt density of the element. Less power per square inch of element surface means lowering the likelihood of scorching the wort. This way you can take a high watt density element that's rater for 220v and run it at 110v and it will effectively be low or ultra low watt density.
Yes.
This is the only reason I know of for doing this.

Also, its way-easier to calculate the resistance of any given element from its published specifications rather than having to actually buy/borrow one and measuring the resistance.
__________________
How hard can it be?

 
Reply With Quote
Old 09-25-2013, 06:17 PM   #13
raouliii
HBT_SUPPORTER.png
 
raouliii's Avatar
Recipes 
 
Aug 2011
Ponchatoula, LA
Posts: 1,019
Liked 118 Times on 102 Posts


Quote:
Originally Posted by k_mcarthur View Post
..... An element that is meant for 220v can be run on 120v, but it would need to be on a 50a circuit using #8 lead conductors.....
This is false. A 240v element will draw half of its rated current with 120v applied. Unless, of course, its a 240v/100a/24000w element.
__________________
On Tap:
LeftOvers Amber
Rearranger IPA - Chinook, Simcoe, Cascade
Ponchy Pale Ale - Millennium and Willamette
NippleRub Ultra (Light Lager w/Mexican Lager yeast)

In the Chamber:
Nothing

Next Up:
A Light Lager

 
Reply With Quote
Old 09-25-2013, 06:31 PM   #14
k_mcarthur
Recipes 
 
Apr 2013
Atlanta, Georgia
Posts: 363
Liked 31 Times on 28 Posts


Quote:
Originally Posted by raouliii View Post
This is false. A 240v element will draw half of its rated current with 120v applied. Unless, of course, its a 240v/100a/24000w element.
Upon further reading about I understand now I was wrong. I was thinking that wattage stood alone from voltage. I am really trying to understand this, I am not electrical illiterate. I worked for an electrician for a couple of years, but in residential wiring you never use appliances outside if their giving ratings. To be fair, the math wasn't wrong. If you want a 120v element to run at 4500w it would take 37.5a, that just doesn't apply here. This is what I love about homebrewing, learn something new everyday.
__________________
Give a man a beer and he wastes an hour, teach a man to brew and he wastes a lifetime.

 
Reply With Quote
Old 09-25-2013, 07:52 PM   #15
atoughram
Recipes 
 
May 2013
Puyallup, Washington
Posts: 1,688
Liked 241 Times on 181 Posts


Quote:
Originally Posted by raouliii View Post
FWIW, in theory, a 4500W/240V (12.8ohms) element should draw about 18.8amps with 240V applied.

That same element should draw about 9.4amps with 120V applied, and provide about 1125w of heat.
My mistake - I havent looked at the element in ten years or so - it's a 5KW @220vac element.

5KW / 220vac = 22.72 amps

220Vac/22.72a = 9.7ohms

120vac/9.7ohms = 12.3amps - about what I was measuring

12.3amps X 120vac = 1476VA, approximately 1476 watts assuming a purely resistive load.
__________________
Clover Creek Brewery, Puyallup WA Home Brewers of Puget Sound
Planning - Something Sinister....
Fermenters - O2
On tap
Centennial Blonde OG 1.040, Carbon River Hefeweizen OG 1.054, SAMM I am IPA 1.069

 
Reply With Quote
Old 09-25-2013, 07:53 PM   #16
atoughram
Recipes 
 
May 2013
Puyallup, Washington
Posts: 1,688
Liked 241 Times on 181 Posts


Quote:
Originally Posted by raouliii View Post
This is false. A 240v element will draw half of its rated current with 120v applied. Unless, of course, its a 240v/100a/24000w element.
and the wattage will be closer to one quarter the 240V rating...
__________________
Clover Creek Brewery, Puyallup WA Home Brewers of Puget Sound
Planning - Something Sinister....
Fermenters - O2
On tap
Centennial Blonde OG 1.040, Carbon River Hefeweizen OG 1.054, SAMM I am IPA 1.069

Wynne-R Likes This 
Reply With Quote
Old 09-26-2013, 12:08 PM   #17
TheWortLord
Recipes 
 
Jun 2012
Phoenixville, Pennsylvania
Posts: 20
Liked 1 Times on 1 Posts


Thanks to everyone for this refresher course electrical engineering! The main reason I will be running a 240v element on 120v is that I and trying to fit my element in a much smaller vessel and the choices for 240v elements are much more varied. I also don't have a dedicated 240v line and I was very worried about overloading my 15A breaker.

 
Reply With Quote


Reply
Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Installing a water heater element thargrav Electric Brewing 29 06-15-2012 07:40 PM
Vertical hot water heater element? crazyirishman34 Electric Brewing 5 02-08-2012 06:00 PM
water heater element adapter Lucky_Chicken Electric Brewing 6 12-14-2011 11:12 PM
Short Water Heater Element? alowell Brew Stands 9 09-23-2010 07:05 PM
How to ground a water heater element torpshootr Equipment/Sanitation 11 01-12-2007 09:05 PM


Forum Jump