Bogus PIDs and SSRs?

[r8rphan]

A 50A GFCI breaker may not be such a bargain. You need to wire with 6AWG for 50A vs. 10AWG for 30A. To use 10AWG wiring with a 50A breaker, you need to have a 30A breaker upstream of the 50A'er (in which case the 50A device is only being used for the GFCI functionality.)

Brew on

Naw, you only need #8 THHN for a 50 amp protected load center... Remember, you size the 'wire' according to the load it will be supplying, which can only be 80% of the wire's rated ampacity... The breaker is only protecting the wire and has nothing to do with the load.. Size the wore to 125% of the load, and then size the breaker to the wire it is protecting..


The load center will be for bringing power out to the screened porch which will feed several outlets inside and outside the porch, the brew system, lighting for the porch and outside the porch and a feed out to the picnic area under the firs and cedars, where I'm working on slowly leveling it all out, putting in a big firepit, stone grill/smoker/pizza oven, a concrete picnic table with SS wells in the middle for ice and beverage, a water feature, lighting, and a sound system... Even running a 2" PVC line out there for a 24ch snake so I can set up my mixer out there and jam with friends on the deck I'm building outside the porch... more labor to do all this than money...

:rockin:

It's part of the 20 year plan.. lol... When you don't have a lot of money, you have to go so slow so you have a lot of time to plan (and collect rocks for the grill and stuff)...

It's all part of the master plan... Hope I live long enough to see it!

Just so you know, #8 THHN is rated for 45 amps.. When the wire ampacity does not correspond to available breaker sizes, you are allowed to use the next larger size breaker that does exist... in this case 50A.. The code lists all the sizes breakers come in...

Also, FYI, you are allowed to downsize the neutral on 3 wire 240v feeder circuits... actually, this is legal on 120/208 and 277/480v 3 and 4 wire feeder circuits too.... (not on branch circuits though), so I could even go with #10 there, but I probably won't do that as I have miles of scrap wire around here to use for the feeder...

I'll be putting a regular 30A 2P breaker in the load center on the porch to feed an outlet for the brew system... The 50A GFI will be in the panel in the house that feeds the load center...

 

[doug293cz]

You're missing the other hot in that circuit... It's a 230v system being supplied with 115.. Or is that what you were intending?

...

Here's the US version of the minimal DSPR110 control panel. Note the differences with the EU version here.



Brew on

 

[PeteNMA]

The 20% derating only applies to continuous loads which is a load applied for more than three hours.

 

[kal]

The 20% derating only applies to continuous loads which is a load applied for more than three hours.

True, but only part of the story.

This topic is a point of debate amongst electric brewers as it is somewhat open to individual interpretation of the electrical code (which may vary by region). The electrical code in the US and many other places states "the wiring for a continuously loaded appliance without a motor needs to be rated at 125% of the marked rating of that appliance". In other words, do not use more than 80% capacity. The electrical code defines a continuous load as "A load where the maximum current is expected to continue for 3 hours or more" and goes further to state that "A fixed storage-type water heater that has a capacity of 120 gal or less shall be considered a continuous load". That last part of the gotcha/confusion/grey area.

The arguments made for and against using more than 80% for a brewing setup typically revolve around whether someone thinks that the elements will be fired for more than 3 hours continuously and/or whether or not an electric brewing setup is classified as a "fixed storage-type water heater" (given that we use the electric heating elements found in hot water tanks and the functionality is somewhat similar).

So YMMV. Just something to keep in mind.

Kal

 

[doug293cz]

Naw, you only need #8 THHN for a 50 amp protected load center... Remember, you size the 'wire' according to the load it will be supplying, which can only be 80% of the wire's rated ampacity... The breaker is only protecting the wire and has nothing to do with the load.. Size the wore to 125% of the load, and then size the breaker to the wire it is protecting..

...

Just so you know, #8 THHN is rated for 45 amps.. When the wire ampacity does not correspond to available breaker sizes, you are allowed to use the next larger size breaker that does exist... in this case 50A.. The code lists all the sizes breakers come in...

I did some more checking, and THHN is 90˚C rated wire, and Cu 8AWG THHN is actually rated up to 55A. Whereas, the 60˚C rated 8AWG wires are only rated for 40A. Guess I need to look at more than just the sticky in the Electric Brewing forum.

Thanks, I learned something today.

Brew on

 

[r8rphan]

I did some more checking, and THHN is 90˚C rated wire, and Cu 8AWG THHN is actually rated up to 55A. Whereas, the 60˚C rated 8AWG wires are only rated for 40A. Guess I need to look at more than just the sticky in the Electric Brewing forum.

Thanks, I learned something today.

Brew on

You could be right, I knew it was somewhere in between breaker sizes, been a while since I looked.. I just know I use #8 to feed load centers with 50A breakers ahead of them all the time...

If I am in doubt, I just look it up..

And remember, if no breaker size corresponds to your wire ampacity, you are allowed to use the next larger size breaker..

 

[r8rphan]

The 20% derating only applies to continuous loads which is a load applied for more than three hours.

Not entirely true.. It's applied to things like receptacles, etc.. With each duplex receptacle counting as 150 watts, you are only allowed to hook up enough of them to go up to the 80% threshold... There are all kinds of things it is applied to..

As a 'general rule' you figure 80% as the max you want to load a circuit up... continuous or not...Then again, for our purposes it's not really an issue...

If you go out and stick an ammeter on the service drop to your house, you'll find it rarely is over 15-20A... They require overbuilding electrical systems like crazy for the end user... For the utility... not so much... They base it on that 15 or 20A... But the county makes you base it on 200A or whatever.. Like everything else involving the govt, there are two sets of rules.. lol

By the way, in the tables and examples of the NEC, when you have to go through load calcs for the entire residence/structure, you'll often find that you have to derate things to considerably more than 20%.... Then there are other factors that cause even more derating, like conduit fill, etc...

 

[SpentBrains]

...a point of debate amongst electric brewers as it is somewhat open to individual interpretation of the electrical code...

So true! For that reason I have piggy backed my GFCI "spa panel" like a plug in appliance. It is technically "removable". If I ever move, or take my entire rig to another location to brew (both doubtful), the whole kit & caboodle unplugs.

I drove a separate new ground rod outside, but near where I mounted my spa box which is secured to the wall on a quick detach mount plate. A short pigtail "inlet", plugs the spa box into, the previous homeowner installed 3 wire x 6 gauge 50 amp breaker protected wall outlet. I've used that successfully for a welder and plasma cutter in the shop for years. From the out line on the spa box, I have about 30' of drop cord that plugs into the recessed NEMA inlet, I built into the brew sculpture (thanks to Kal's online guidance).

If ever anybody with any real or self anointed authority... like a know it all real-estate agent, or one of his wanna-be otherwise unemployable son-in-law/home inspectors, or even god forbid a real local building inspector, ever wants to talk about "electrical codes", I'll just unplug my "portable device", GFCI, ground, brew-rig and all, thereby ending the argument.

 

[r8rphan]

I plan to do solar exactly the same way... on a trailer, hooked into the house via temp power cord, and I have even considered buying a couple old golf carts to use as battery storage... How many people can unhook their backup power system and drive it around?

As long as it is all kept on private property, then no governing authority has jurisdiction over it...