Was planning on 120V, now thinking 240V...

Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum

Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

kerklein2

Well-Known Member
Joined
Dec 30, 2008
Messages
393
Reaction score
20
Location
Austin
I was originally planning on building my system for 240V since my only outlet is in my utility closet and I'm in an apartment. Now I've decided I'll be brewing on the balcony and was going to have a 25ft. cable run for my 120V system anyway.

I have a couple concerns that I wanted to ask this board. First, for the 240V outlet I'd have to do a cable run of something like 32-35ft. With a 10-4 SOOW cable rated for 30A, is this too long? A calculator I found online comes up with .035 ohms for 35ft of 10AWG wire. At 240V that's 20W. I don't really have a frame of reference for how bad that is.

My 2nd concern is GFI. My dryer outlet does not currently have GFI protection at the breaker. Since it's an apartment, I don't think getting one installed is an option. Could I put one inside my control box and still get the safety I need? Are there any other options or should I stick to 120V?
 
You can get an inline GFI or something like a spa panel for the GFI issue. I dont have an answer for the cord length issue though
 
10-4 is fine for 35'. I have made runs quite a bit further than that with out any trouble with 10 gauge.
 
Thanks. I've just found those inline GFIs. Unfortunately they are not cheap at all. A spa panel at Home Depot is $50 but it's unclear what it's connection is. Are there connectors on it or do I run wire straight into it?
 
You run wire straight into it. Buy a dryer cord at the hardware store and strip the ends of the wires - insert these into the terminal blocks, tighten the screws to secure and you have the input side connected.
 
Thanks. I've just found those inline GFIs. Unfortunately they are not cheap at all. A spa panel at Home Depot is $50 but it's unclear what it's connection is. Are there connectors on it or do I run wire straight into it?
Is your dryer outlet a 4 prong or 3 prong outlet?

I've made drawings for both setups using the HomeDepot GE Spa Panel that might help you.

power-panel-5b.jpg



power-panel-6.jpg
 
Dryer outlet is 4 prong. On the power output side, is that just your cable exiting through a cable gland or something? Or did you put a panel mount outlet on the side?
 
In case you are interested I just did my second batch on my 120v system. I use two 2000w elements and a simple switch box to turn them on and off. I do all grain BIAB.

With both elements on its easy to get 6 or 7 gallons up to boil. I can keep it boiling with just one element. Or turn on both for an aggressive boil.

Scorching has not been a problem either.

Picture after yesterday's 90 minute boil...

image-2821071985.jpg
 
NO. You should not use a cable with a lower current capacity than the circuit breaker.

In general this is true. But since you've said that the dryer outlet that this is plugged into is a 30A breaker, you're fine using the 10AWG - although 100' is a long run, I'm not sure about that. You know how much 100' 10 gauge is going to cost you right?
 
boswell said:
Seatbelt, have a build thread anywhere? I'm leaning towards this route.

Good idea. I don't. I just built it two weeks ago. I will take some pics and post soon.

It was easy.
 
So I've just noticed that 10-4 rubber cord is only rated to 25A. Since this is less than the breaker AND really close to total system current (5500W element + pump + PIDs and such) it seems I should go up to 8-4 to get 35A correct? That stuff ain't cheap.
 
bruin_ale said:
In general this is true. But since you've said that the dryer outlet that this is plugged into is a 30A breaker, you're fine using the 10AWG - although 100' is a long run, I'm not sure about that. You know how much 100' 10 gauge is going to cost you right?

125 bucks. I already bought it!
 
Interesting.. from the above website:

"UL General-Use guidance for Ampacity of current-carrying conductors is contingent upon length (50 Feet or less) and number of current carrying conductors. Fifty Feet or less 30 amp with 2 hots and 25 amp with 3 hots. Over Fifty Feet 25 amp with 2 hots and 20 amp with 3 hots."
 
Dryer outlet is 4 prong. On the power output side, is that just your cable exiting through a cable gland or something? Or did you put a panel mount outlet on the side?
Here is a picture of the panel that someone set up with the outlet directly mounted in it. On his setup he used bx cable for the feed. I believe you will be using a plug and cord for the input power.

Spa-Panel.jpg



I hope this helps you.
 
If going from 3-wire 240V into spa panel as shown would I still get to use 120V off one of the 240V legs like I am now with 4-wire 240V? If so that would be awesome as I built my panel around 4-wire 240V then moved to older apartment where both dryer and range are 3-wire and I'm stuck with running extension cords for pump and power for BCS-460 controller.
 
If going from 3-wire 240V into spa panel as shown would I still get to use 120V off one of the 240V legs like I am now with 4-wire 240V? If so that would be awesome as I built my panel around 4-wire 240V then moved to older apartment where both dryer and range are 3-wire and I'm stuck with running extension cords for pump and power for BCS-460 controller.

It will work. You will be using an equipment ground as a neutral though. This was allowed in the past as a way around supplying a neutral to 120V control systems in 240V appliances. A bare ground wire is not intended to carry current. If you are using it that way it is "technically" not correct.
 
Well the stuff Home Depot has (Cerro Wire) is only 25A, as is anything McMaster has. But I just found this that is 30A as well as nice and cheap. I'll be going with it.

http://lockingpowercords.com/Products/513-104-soow-wire.aspx

The temperature rating is critical in the ampacity rating. Most wire/cable is rated at 90C. Most connectors and some cable is rated at 75C. Lower temp rating-->lower amp rating. You will be fine using #10 protected at 30A. Derating for length is generally only necessary over 100 feet.
 
Back
Top