50 amp twist lock connectors are crazy expensive (not like the 30 amp are not)... right now I am building a 30 amp control panel, I don't foresee a reason to ever need more than one element on at a time but who knows. One 4500W element and 2 chugger pumps is just under 20amps. Think it would be safe to use the L14-30 at 35-40 amps? If I ever upgraded to 50amp service?
NEMA L14-30 >30amps
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if you are building a 30 amp panel, why are you concerned with drawing 35-40 amps? or is it a typo and you are building a 50 amp control panel?
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If you did decide to upgrade then no. The ratings of the plugs/wires are not rated for the event of a 50amp load traveling through them.
iijakii
Well-Known Member
Size your wires and components for 30A, and if you ever decide to step-up to a back-to-back setup then sell your current panel at a slight profit (assuming you do decent work) and build a new 50A one.
Just look at the price of wire alone, going unnecessarily larger is incredibly expensive.
Just look at the price of wire alone, going unnecessarily larger is incredibly expensive.
or you could tweak the existing panel. not sure how complicated the op panel is but it might be as simple as swapping out the incoming receptacle, a contactor and some internal wiring. wiring for the elements, pumps, controllers, lights, etc. should mainly remain unchanged.
of course, the big cost could be the branch circuit to the panel itself. upgrading from #10 to #6 can be expensive, especially if walls are finished, etc.
Guys I am only talking about the physical power-in connectors. No single component is going to draw more then 20 amps so inside of my panel 10awg will be fine. I am only curious about the physical connector for the main power coming in. Assume that the wire coming from the breaker to the panel is the appropriate gauge for the run length and 80% draw.
The panel has 1 power input and 2 outputs for 2 elements but a 3-way prevents both from firing in its current configuration. I am just curious what would happen if I pushed 40amp though a L14-30 twistlock main power in connector with appropriate wires.
The panel has 1 power input and 2 outputs for 2 elements but a 3-way prevents both from firing in its current configuration. I am just curious what would happen if I pushed 40amp though a L14-30 twistlock main power in connector with appropriate wires.
iijakii
Well-Known Member
Maybe nothing. Maybe it melts. Maybe your panel catches on fire.
FuzzeWuzze
I Love DIY
The short answer, No.
If its a possibility, just make sure any wiring that will hold the full load is rated correctly as others said. This means at least one 50A contactor and proper size wiring going to it. Then as others said you can just swap the connector later.
If its a possibility, just make sure any wiring that will hold the full load is rated correctly as others said. This means at least one 50A contactor and proper size wiring going to it. Then as others said you can just swap the connector later.
dyqik
Well-Known Member
I can report that NEMA 14-30 twist locks plugs can melt with about 24A passing through them if the receptacle they are plugged into starts to get loose or corroded contacts. One of my helium compressors for a cryostat at work failed like this last year.
It might work fine for a short while, and then fail (possibly catastrophically) at some point in time.
that is an installation issue, a properly installed 14-30 plug can carry 30 amps continuously. but to the poster's original question, pushing more than 30 amps through the plug might cause a problem, might not. it is only tested and listed for up to 30 amps of operation so anything beyond that is a crapshoot.
it is like a rope rated for 50 pounds. will it break if i put 55 pounds on it? maybe, maybe not but for me personally, i would get a bigger rope. same with the panel...
dyqik
Well-Known Member
Yes, that's an installation issue, but it was an installation issue that tested out and operated fine for several years before failing, and it failed even while well within ratings. Even if everything is built to rating, you still need to inspect and check regularly. And if you decide to try and exceed ratings (there is, after all, a safety factor in any engineering), then just because it doesn't fail immediately, that doesn't make it safe. The chances of it failing catastrophically due to general degradation is significantly higher than for something within ratings.
My two cents...No I am not an electrician, but I do try to follow code, usually going above an beyond.
the L14-30 is rated at 30 amps, stay below that. Now what I would do is plan for going larger in the panel. The Feed cord should be 6-8 gauge, the the feed from the internal connection to the various phase break outs should also be 6-8 from there you can drop down to 10-14 through breakers depending on what you are suppling. Not sure why others called for 50 amp contactors, see this drawing "50a 5500 3 Element 3 outlet BCS 460 RIMS" under List of "PJ Electrical Diagrams."
Of course the inlet to the panel would have to changed if you do decide to run 50 Amp, unless you attaching the cord straight to the phase break outs.
See post below for more info.
Martin
the L14-30 is rated at 30 amps, stay below that. Now what I would do is plan for going larger in the panel. The Feed cord should be 6-8 gauge, the the feed from the internal connection to the various phase break outs should also be 6-8 from there you can drop down to 10-14 through breakers depending on what you are suppling. Not sure why others called for 50 amp contactors, see this drawing "50a 5500 3 Element 3 outlet BCS 460 RIMS" under List of "PJ Electrical Diagrams."
Of course the inlet to the panel would have to changed if you do decide to run 50 Amp, unless you attaching the cord straight to the phase break outs.
See post below for more info.
Martin
if the panel design includes a main power contactor, it will need to be rated for 50 amp. if there is no main power contactor in the panel, no worries!
and for the incoming branch circuit, it will need to be #6 if romex to meet code. it can be #8 if it is thhn/thwn and the upstream circuit breaker and 14-30 plug/receptacle has 75 degree c rated terminals.
augiedoggy
Well-Known Member
except the componets would be wired differently and as mentioned the main wiring and incoming power wire would have to support 50 amps... it makes more sense to just ues the correct size components for the current size and replace the whole panel or upgrade the connectors with the wiring later. especially since the need for 50a just isnt there unless someone is operating a nanobrewery and needs 2 elements at once or if they cant wait the extra 30 minutes on back to back brews.
Its just another one of these what ifs and "while im at it" things that will likely just cost the owner money now rather than save him anything on an upgrade he likely wont do and honestly would have to pull everything apart to rewire anyway if he did...
augiedoggy
Well-Known Member
I agree here... it would have been about $150 more for me to go 50 amps and im my case im glad I didnt.
augiedoggy
Well-Known Member
wouldnt that be the case for ANY connector? I mean the poor connection point and damaged receptacle was the cause of the problem not the properly rated connector right? the poor connection increased resistance and heated the metal beyond what the plastic was designed for... The outlet was likely abused or misused. outlets dont normally get loose with normal usage.
How many times do you plan on unplugging and plugging this control panel in? is it portable?
i think we are saying the same thing, build the panel now for exactly what you need and upgrade components in the panel later if you want to go bigger. someone suggested a completely new panel when going to 50 amps and that isn't necessary.
the big one is that main incoming circuit. the differential cost is relatively small. if using romex, it is only about 40 cents or so more per foot for #6 vs #10.
augiedoggy
Well-Known Member
Its not necessary but I see his point too... Often there are a lot of things one learns once they have used their setup for a while... this turns into a list of "upgrades" and things to rearrange so in that respect I could see that a new panel could be more cost effective in many cases... Look at how many people build a second or even third revisions of a panel as their process evolves... I upgraded my existing panel and it was tough to fit everything... I have the benefit of just being able to replace my front panel cover but most dont. I ended up adding a third element and multiple float/flow switched safety cutouts as well as a third pump and better alarm setup.
augiedoggy
Well-Known Member
For me the cost would have been about double for the #6 and dont forget its much harder to fish through existing walls and run...
I have a 60amp hot tube and remamber the joys of running the #6 for that all too well...This was another reason I did not go with 50 amp since my 100 amp main service is basically tapped out now between the reef tank and hot tube and the rest of the house.
I built my panel with this in mind. If I ever go to 50amps, all I have to do is buy the larger receptacle and one more 25amp DIN breaker and some 6 gauge wire. All the changes would be isolated to a single corner of my panel.
yep, lots of different ways to skin a cat, everyone will have a different situation. i would caution if folks are even thinking about 50 amp, might as well do the 'hard part' up front (the incoming branch circuit).
i'm with you, can't conceive of a situation where i will need 50 amps. back-to back 10 gallon batches? 30 gallons at once? not gonna happen.*
*famous last words
Lots of people seemed to miss the point of this post. A 5500W element draws at most 22amps at 240V meaning 10awg is fine everywhere inside the panel except for the wire coming from the power in socket to the main contactor. All my contactors are rated for 40amp right now so besides needing to upgrade the contactor in the future the only other component I was concerned about was the power in outlet. Pretty much getting the answer I expected out of it but I didn't know if anyone had any real insight into how they are made. I know in a lot of industries the cost to certify stuff with UL is expensive so even if they might sell 2 products with different ratings, they might actually be tested to go higher with no problem, only difference is the labeling.
augiedoggy
Well-Known Member
5500w element can draw 23 amps since you will find your 240v will fluctuate and dip down in the 230's...
When it comes to contactors there would be no benefit to advertise a 40a contactor as a lower rated one Since you can always use a higher rated contactor for smaller loads without concern.. if anything its safer. it would be foolish to do so in this case.
Usually its when something is made and marketed for something else that its not rated for another application where it may be fine... this is sometimes the case with wire when the insulation is approved for a specific application... automotive wire for example. depending on the application it may be fine or it may break down with strong AC current so I've been told.
the wiring kit I bought from harbor frieght is apparently for decorative purposes only since I found no ratings or certifications on it or its packaging at all... Its been fine for 3 years in my panel now though... I used the coreect sized wire for each application and didnt waste time worrying.
and 10awg is rated for 30 amps...a 5500w element and even multiple pumps wont draw that much so you could use that for your main power wire especially if its SJ or SO insulated wire which can be used for higher amounts of draw.... the 12/2 I use for my elements is rated for 25a because of the insulation and application.
I didn't think this would be the case with the contactors but it seemed like it was in the realm of possibilities for the plug/outlet components.
There is a reason (probably more than one) that it's rated 30A. Just because the reason may not be immediately obvious doesn't mean the reason is invalid. Do yourself a favor, stay within the published ratings.
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I agree with whoareu. I don't understand why, electrical thread after electrical thread, people wax poetic about why and how they can ignore ratings and code. What is the real justification: to save a few pennies or because they don't want to put the time in do proper research?
50A / 240V is a lot of juice, which can do a lot of damage quickly. Use the right wire, the right connectors, the right devices, and the right tools. And live in the world of the uneventful. If you want to see fire, smoke, and explosions - it's easily found on YouTube.
Ok, rant over, time for a homebrew!
-BD
50A / 240V is a lot of juice, which can do a lot of damage quickly. Use the right wire, the right connectors, the right devices, and the right tools. And live in the world of the uneventful. If you want to see fire, smoke, and explosions - it's easily found on YouTube.
Ok, rant over, time for a homebrew!
-BD
Augie your statement is inaccurate. A heating element has constant resistance regardless of applied voltage. It is not true to say I=5500W/230V=23.91A, here's why:
(1) Power = Current * Voltage
(2) Current = Voltage / Resistance (Ohm's law)
Put them together and you get Power = V^2/R, or R=V^2/P.
Thus your 5500W/240V element has an R of 240^2/5500 = 10.47 ohm.
If you apply 230V to 10.47ohm you get I=21.967A.
If your voltage goes up to 250V though, you can get I=23.88A.
Schematix your math is correct but input is not. The element is rated 240VAC / 5500W. 5500 / 240 = 22.9 A. Downrate that by multiplying by 230/240 (=~22A) and update by multiplying by 250/240 (=~24A).
-BD
-BD
I don't get what you're saying about the "input is not" because it appears you both came up with the same numbers (albeit yours rounded to one decimal point).
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My less practical concern than can it handle it is when I want to move from 30 to 50 amp plug on the enclosure... How hard will it be to resize the whole and maintain my industrial decay aesthetic?
augiedoggy
Well-Known Member
Yes your correct, I was thinking backwards... My point was that the amp draw varies with voltage although its unlikely the home voltage will hit 250... in reality the 5500w element will likely draw around 20-21 amps as most are weaker than advertised.
The10mmKid
Well-Known Member
Safe, probably. The right thing to do, definitely NOT.
Physically, you'll have a difficult time working 50A cord into the connector.
Amazon has connectors for $100 per set. For $20 more, you can get a 50A 15' cord set and have pigtails on each end of your setup. I.E., couple feet out of the SPA panel, 13' on your control panel. (or vise-versa)
'da Kid
You are correct amp draw does vary with voltage. The power can vary significantly with voltage.
Using that 5500W/240V=10.47ohm heating element as an example:
@230V = 230^2/10.47 = 5053W = 91.8% rated power
@250V = 250^2/10.47 = 5969W = 108.5% rated power
BD I'm not sure what you're taking issue with here. Augie said a 5500W/240V element will draw 23A at 230V. That isn't true.
Your numbers are correct (although rounded) too, which also agrees with my original reply.
Yes, my bad. I misread and reacted. Apologies!!
Just getting bent when people say it's ok to ignore ratings and standards. With high power electricity inside your home, around liquids, and serious heating elements, standards should be strictly followed IMO.
-BD
Just getting bent when people say it's ok to ignore ratings and standards. With high power electricity inside your home, around liquids, and serious heating elements, standards should be strictly followed IMO.
-BD
No problem.
In most regards electrical standards are extremely conservative. In marginal cases it may be ok to bend the 'rules' if you know what you're doing, but in the case of the OP, I think he's trying to push the limits too far.
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