Extension Cords - what is enough?

4given · June 20, 2012, 12:01:50 PM

So.......

I just looked on the Bradley website and they indicate that my Bradley OBS (US Model) draws 5.5 amps. I assume this is at a full load. (Smoker box on high - smoke generator on)

A 50ft extension cord with mere 16ga wire is rated at 13 amps. Why is this not sufficient as many folks here on the board claim? :-\

Or maybe it is sufficient and anything else is just the product of a rumor started by the ECMRA (Extension Cord Manufacturers and Retailers Asscoiation) ;D :P

Opinions anyone?

How about you electricians, engineers, instrument techs and etc? Care to explain this all to me before I go dump $70.00 on a 12ga cord?

Kahunas · June 20, 2012, 01:26:41 PM

The longer the extension cord the more the loss you get. Think of it as water flow.....long skinny river vs. a short wide river.......16 guage vs. 12 guage. You will get a lot less current drop through a short (wide river) 12 guage wire than a long 16 guage. It is optimum to not even use an extension cord if possible but that is not always easy to do. I myself need a 15ft cord and use 12 guage. Hope this helps muddy the river so to speak..

Alanfromwis · June 20, 2012, 01:32:13 PM

4given,
16 gague is not enough for a long cord since that cause the cord to run warm and increase its voltage drop over time. That would not be good on a long smoke. Also your house or garage wiring probably has 12 gague to the outlets now. On a real short run you maybe ok with 14 gague, but I wouldn't use less.
alanfromwis

4given · June 20, 2012, 04:25:58 PM

Quote from: Kahunas on June 20, 2012, 01:26:41 PM
The longer the extension cord the more the loss you get. Think of it as water flow.....long skinny river vs. a short wide river.......16 guage vs. 12 guage. You will get a lot less current drop through a short (wide river) 12 guage wire than a long 16 guage. It is optimum to not even use an extension cord if possible but that is not always easy to do. I myself need a 15ft cord and use 12 guage. Hope this helps muddy the river so to speak..

Thanks for your reply! :)

I understand the water analogy when it comes to electricity. Amperage is flow (GPM) and wire size or guage is the size of the river, pipe or what ever conduit you choose for the analogy. Ohms is it's resistance to flow (TDH) . Voltage is pressure (PSI).

The larger the conduit, the less resistance to flow and the more flow you can get through it with the same pressure.

Since my 50 foot 16/3 cord is rated to carry 13 amps at 125 volts it should carry a mere 5.5 amps with ease! In other words my "river" or "pipe" is plenty big enough to carry the amount of flow required for my Bradley to operate at maximum efficency. My Bradley is only using 42% of this cord's flow carrying capacity!

A 50ft 12/3 cord is rated to carry 15 amps at 125 volts. Only 2 amps more. My Bradly is still only going to draw 5.5 amps MAX unless it malfuntions. So now with the 12/3 cord I am only sing 36.66% of the cords capacity.

So unless my 50ft 16/3 cord is damaged or I have another load on the circut I am plugged into, it should actually be of sufficent capacity to actually run not only ONE but TWO Bradleys at the same time at normal MAX amperage draw.

Am I right or am I wrong? If I am wrong.... how so and what am I not factoring in?
:)

Smokin Sparky · June 20, 2012, 05:45:15 PM

What I did was to make my own extention cord. Being an electrician, I deal with voltage drop on a regular basic. Basically, the longer the length of the conductor, the greater the voltage.drop. Also, as voltage decreases, current will in turn increase. To compensate for voltage drop, larger gauge wire must be used. That is why when I needed a 15 foot extention cord, I went and bought 15 feet of 10/3 SEOW cord and attached a plug and receptacle to it. Although at this length voltage drop would be negligible I am sure that any load would be easily handled.

4given · June 20, 2012, 08:28:19 PM

Quote from: Smokin Sparky on June 20, 2012, 05:45:15 PM
What I did was to make my own extention cord. Being an electrician, I deal with voltage drop on a regular basic. Basically, the longer the length of the conductor, the greater the voltage.drop. Also, as voltage decreases, current will in turn increase. To compensate for voltage drop, larger gauge wire must be used. That is why when I needed a 15 foot extention cord, I went and bought 15 feet of 10/3 SEOW cord and attached a plug and receptacle to it. Although at this length voltage drop would be negligible I am sure that any load would be easily handled.

I was hoping you would comment on this Sparky. So you are saying that in my 50ft 16/3 cord senario the issue is my voltage will drop below 120v? I thought the cord rating of 13 amps @125V ment that is what the conductor was capable of. How would we figure the voltage drop mathmatically?

4given · June 20, 2012, 09:15:16 PM

OK I found several voltage drop calculators on line. The results are a little different but close. Here is a link to the one I used that was easy to use: http://calculator.net/voltage-drop-calculator.html

It told me that a 50ft run of 16ga would result in a voltage drop of 2.21V
14 ga would be 1.39v drop
12 ga would be .87v drop and.........
10 ga would be .55v drop.

I am begining to understand..... are these voltage drops enough to significantly impact performance???? :-\

beefmann · June 21, 2012, 08:24:01 AM

good site to use as reference

3rensho · June 21, 2012, 08:47:24 AM

One could also get a 220v smoker (like we use here) ;D

4given · June 22, 2012, 06:06:38 AM

Well I talked to our electrician at work about all this. This morning he came in to work and gave me as a gift a 50 foot 10-3 cord! :)

Guess who is getting a gift of smoked meat and cheese? ;)

The Lord is good! ;D

Alanfromwis · June 22, 2012, 08:05:53 AM

Quote from: 4given on June 22, 2012, 06:06:38 AM
Well I talked to our electrician at work about all this. This morning he came in to work and gave me as a gift a 50 foot 10-3 cord! :)

Guess who is getting a gift of smoked meat and cheese? ;)

The Lord is good! ;D
4given
Sounds like you got your question answered with a very nice gesture on your electrician's part. Glad to hear it & happy smoking.
alanfromwis
quote]

4given · June 22, 2012, 11:33:00 AM

He said it was overkill but he wanted me to be confident. Great guy!

Quarlow · June 22, 2012, 10:01:08 PM

10 GA is overkill but what does it hurt. I like to think like this, try to fill a 5 gal. bucket with a 1 inch hose at 10 psi and then try with a 1/4 inch hose at the same 10 psi. You know which will take longer. Nice gift and he should be rewarded handsomely.

Extension Cords - what is enough?

beefmann