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Comment by cpascal | Hacker News Reader

> There are several points here that probably don't comply with code. The fact that an extension cord has been brought into a permanent circuit is probably one of them.

If you wanted to do this up to code, how would you do it?

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No matter how much better some things might be, it's whether it's in the code or not that dictates if your house wouldn't pass an inspection.

One of the things I think would be most likely to throw up a red flag and immediate fail would be the "suicide plugs".

Even though they're not energized (but rather, used to deliver power to the remote end), most electricians and inspectors wouldn't sit around waiting for you to explain your brilliant power delivery scheme.

The only real way to do this stuff code-compliant would be to purchase and install a real hard-wired UPS system, use properly-installed Romex (or other suitable code-compliant wiring), and get things inspected by the local authorities.

Usually if it's not installed by a licensed electrician, the inspectors will be even more stringent.

Those are not suicide plugs and what is there is code compliant.

Suicide plugs refers to extension cords which have been built (or modified) so they are male/male. One in which the far end will be exposed while energized. In this system, the male plugs will never be energized while exposed.

I understand that, what I'm saying is you'll have to spend some time explaining to the inspector how this system works, and they'll give an immediate fail (unless they're pretty lax—I know in the midwest they are not) unless you're a licensed electrician.

Mostly because 'sparkies' often wire things up like this and use random extension cords in walls and create fun fire hazards.

I agree that the installation is in 'the spirit of the code', but there are enough little variances that I would take a bet that a random inspector would not pass it on first glance.

Live in Midwest. Current home had an exemption cord running in a ceiling through a hole drilled to outside powering a light. My inspector said it was “interesting” and could cut and cap the cord if I was worried.

Not sure where all this worry of code when selling a house comes from. Code changes. No 20 year old house is up to current code, doesn’t mean you can’t sell it.

Those plugs are legal, and commonly installed for generators. The only part the inspector sould question is why they are not connected to a breaker to protect the wiring.

I was wondering if those would require an ED of some sort in line of sight. I know that permanently wired things like HVAC or Water heaters do, but I've never read up on that sort of connector.

I was wondering if those would require an ED of some sort in line of sight.

NEC 400.7(A) Flexible Cords point 11 would seem to allow it so long as it was 1-to-1 inlet to outlet.

Flexible cords and cables shall be used only for the following...(11) Between an existing receptacle outlet and an inlet, where the inlet provides power to an additional single receptacle outlet. The wiring interconnecting [...] shall be a Chapter 3 wiring method. [...]

I don't know what Chapter 3 is though, and in the below study guide link it seems to show a double outlet in the graphic.

https://www.electricallicenserenewal.com/Electrical-Continui...

thats old code, nec is now 2020. i dont have an nec codebook...but pretty sure you cant use extension cord connected to the ups connected to another receptacle...the section of the relevant code would be labeled something like 'uses not permitted.'

the code you referenced states 'Between an existing receptacle outlet and an inlet'

the circuit is also unlikely to be arc fault protected, which would mostly likely be required.

also how the romex is run, is not to code.

Thanks for digging that up, it looks like I am actually golden then

I think the biggest problem is that an energized in-wall circuit must have an upstream circuit breaker. His new circuits do not, and rely on the source power supply being connected to a breaker. Because the power supply is a UPS, turning all the breakers off will not cut power to that circuit.

I agree with this, and adding a breaker between the UPS and load is probably the solution. The trouble is many UPS units have a set of controlled output banks and the ideal solution is extending controlled output to the wall breakers downstream of the UPS.

The UPS does have breakers though

This is the problem. You cannot rely on the circuit interruption capabilities of whatever devices happen to be installed on that circuit at a given point in time. If these were permanently installed, you might have an argument that it is passable.

The situation that is dangerous here is if a power source were to be connected to one of these inlets and it did not have a sufficiently-sized breaker and the other side has a dead short, you are looking at a fire inside your walls.

I just installed a 50 amp generator inlet on my main panel, and even though my generator has a matching 50 amp circuit breaker, I installed a separate matching 2-pole 50a breaker on the inlet circuit. This protects the electrical system from even the most screwed up of generators being connected to the panel.

Surely that could be said for anything though? There is nothing stopping me from getting an adapter to plug a space heater with a cheap 16awg cord with an adapter into a 30a outlet

Here there is a breaker, and if the UPS is disconnected, there is no power. Of course someone could go and plug this into a 30a outlet, however that's something that I wouldn't do, so its not really my issue

In the case of a cheap 16awg cord, yes you have created a dangerous situation, but it is not one that is considered part of a larger structure in terms of code. This is the electrical equivalent of spraying gasoline around at the gas station and acting surprised when it turns out poorly for everyone.

> however that's something that I wouldn't do, so its not really my issue

Electrical code is designed so that even an incompetent operator cannot produce a dangerous situation inside a building's electrical system. OSHA, USCSB, et. al. would be the first to tell you that relying on a specific individual to interlock a dangerous situation can result in extremely adverse outcomes.

>There is nothing stopping me from getting an adapter to plug a space heater with a cheap 16awg cord with an adapter into a 30a outlet

That would be against code.

There's nothing stopping you from running bare wire through your walls.

There's nothing stopping you from not bothering to ground any outlets.

There's nothing stopping you from using 14AWG romex on a 50 amp breaker.

Etc., Etc.

All of that is against code, and I've personally seen all of that in the wild at people's homes, offices, etc.

If you wanted to do things the #rightway, you'd most likely need a subpanel for the UPS to feed.

A breaker panel isn't just used for overcurrent protection, though—it's also a standard point to disconnect power when needed. The possibility of house wiring being energized even when all power to the house is cut is dangerous for anyone not familiar with the setup. This could be lethal if work needs to be done on it and OP isn't around to explain how it's wired up.

True, but signs that there is more than on disconnect are common in industrial settings. They are rare in house situations, but putting a sign on the main breaker box is probably enough to meet code. Though it would surprise the inspector.

This is common in home systems where you have a second power source like solar. Mine has markings like this: https://www.jadelearning.com/blog/pv-system-marking-and-labe...

For starters, when I looked into doing this I found everyone disagreeing if it was code. I personally think it might be up to code actually

If they sell those power inlets which are NEC approved, how can you use them without breaking code? So it MUST be code. But then you ask 10 people and get 10 answers

There are larger UPS's designed for hard-wiring, but they are almost always VERY large. I think that might be the only way to avoid an inlet cord like this

Its definitely not up to code, but that is not really a problem unless you plan to do a larger (permitted) project in the future or when you sell the house and are getting it inspected. The one thing to watch out for is that if your house does burn down (presumably due to reasons not related specifically to the non-code-compliant wiring) the insurance company will try likely try to deny your claim.

At least in my jurisdiction (America) the only way to achieve what you are trying to achieve is by installing a dedicated subpanel fed by the UPS with appropriate breakers. I believe that such an installation would only be code compliant with a UPS that was designed for such an application (with a hard wired output connection, and appropriately designed disconnects), but a lenient inspector might let you get away with feeding a subpanel from an extension cord as long as as of the breakers and capacity factors work out correctly and the grounding meets code.

The biggest issue I see is that the system is not labeled correctly (at all?). That is a pretty serious issue because if, for example, an emergency worker were to come into the house under the expectation that the power to the house was cut (at the service disconnect) but the house would have live outlets that are otherwise unmarked. See https://www.mikeholt.com/download.php?file=PDF/11_Generators... for more information (the relevant section for your system starts at page 16)

As other commenters have pointed out, just because you can buy something that says NEC approved on the sticker does not mean that it is approved for your application. A good example mentioned elsewhere is using a 16awg SJTW extension cord to power a 15a load--all of the connectors will plug together but the combined solution is obviously not code compliant and even if it doesn't melt/catch fire it will not supply the load with clean power.

Electrical code is complex, but more importantly there is not one unified electrical code. Your municipal, county, or state government determines what the electrical code is in your location. Usually it will be the National Electrical Code (NEC) but inclusion, but probably an older version, and then most governments have implemented various changes on top of that.

So the first question to answer is what NEC allows, but you will then need to double-check for your specific context.

Further, the power inlets are NEC approved but that in no way means that they are approved for this use. I'm far from an expert on the NEC but I can pretty confidently assert that it allows such inlets only for specific uses, and you would need to check carefully that what you propose is one of those uses. A very rough rule of thumb is that you are not normally allowed to have more than one "user-removable plug" on the path to a device. There are a number of exceptions to this, but any time you're plugging into something that plugs into something else, you need to check carefully if what you're doing is allowed.

Depending on the rules of your jurisdiction having authority (JHA) it may not be possible for you, as a homeowner, to install such a system in a code complaint way. This will definitely require a permit. Most JHAs make some allowance for homeowners to be permitted to pull permits for work on their own home, but there are usually pretty strict limits on what these permits would cover and I think most JHAs would require that permits for a central UPS be obtained by a licensed electrician.

And as mentioned elsewhere, I doubt the JHA or the manufacturer of the UPS would approve of this kind of installation. There are UPS specifically manufactured for a hardwire installation and that's what ought to be used here. That said, I am sympathetic, because UPS can become very expensive very fast. I'm balking at the cost of 2U rack models from Eaton, he will have had to shell out a good chunk more based on his VA requirements but at least he avoided the significant premium for hardwired.

For starters, you'd secure those NM cables within 8 inches of exiting those plastic boxes, or you'd secure them to the box with a clamp and secure them within 12 inches of the box exit.

After the author began the article by whining about the previous owner's outlet wiring, I expected better attention to detail.

Fished cables do not have that requirement

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