New answers tagged

0

You have an alien breaker problem You must use same-brand breakers in your panel (or certain very specific competitor breakers that are UL-classified for your panel, but those classified breakers are almost never stocked at retail). Combination AFCIs detect both "series" faults (in line with the load, by listening to the wire for crackle-pop noises) and "...


7

We're reading tea leaves here to guess at NFPA's intent. NFPA writes the "model electrical code" which they offer for anyone in the world to adopt as their law. But politically, NFPA has been having a big problem. Normally NEC changes are fairly trivial in cost: Pull a neutral wire on switch loops, gosh, you're using the /3 Romex instead of the /2. It'...


1

They're packing a lot of information in one sentence. They're making a distinction between 3-phase (like New York City and Brazil) and split-phase (everywhere else in 120V-land). Split-phase is really just single-phase, with a tap in the middle. The middle tap goes to neutral, and since neutral is supposed to be near ground potential, we usually don't ...


1

Maybe because arc faults are not more dangerous in those places then in other rooms of a building. The probability of arc faults to go undetected may be even lower in bathrooms, since normally all electric appliances and devices are only switched on if that room is occupied. An arc could be detected by smell, flickering or fume. A fridgerator, A/C unit, ...


7

NEC doesn't require AFCI because it does require GFCI, and they are not the same. GFCI outlets protect against electrical shock and this is very important around water. AFCI protects against electrical arcs that come from damaged cords and bad connections. Arcing is super hot, and is responsible for electrical fires. A combination protection device could ...


7

I believe the simplest way to put it is, it needs to be on a dedicated 40 amp double pole breaker. With a 240 volt appliances there are 2 "hot" lines, usually a red insulated wire and black insulated wire. A neutral, usually a white insulated wire, and a ground wire can be bare wire or sometimes insulated in a green covering. The 4 wire connection is the ...


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You are correct about 15A for #12 aluminum. While some of the current-capacity rules in 310.15 can be complicated, NEC 240.4 wipes them out and forces #12 aluminum to 15A. Remember when terminating aluminum wire, you must use CO-ALR rated receptacles. Copper lugs/screws/terminations are intolerant of aluminum wire. In the rush to aluminum in the 1960s, ...


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Use a standard 15 Amp fuse. You said the wire is #12 AL. That's good for 15 amps. Read and pay attention to Harper's comment.


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Yes, use 15A time delay, the short inrush of motors will not damage the wire. In the US even circuit breakers operate on a time delay, they call it "inverse-time", which really means the same thing. Not sure what type of fuse is used in your country, in the US a FRN15 fuse would have a similar 500%/10 second delay that a typical thermal magnetic breaker ...


1

Yes, this looks right! Great pictures!


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If not violating local codes, there might be a solution via load shedding relais, which avoids parallel use, what should be no problem in this case unless both the electronic control systems - if any - of the units are incompatible. The unit having lower prioritization must be compatible, since only that unit will be shut on/off via the relais or contactor. ...


0

240V heaters are really not a problem. You just don't find them in a shrinkwrapped box on an aisle at Walmart, and you wouldn't want a plug-in heater anyway, since they are very flimsy and don't hold up. So I definitely would not violate at least 3 electrical codes to try to create a 120V socket there; I'd fit a 240V device. Lighting is readily ...


1

You are thinking of a tap rule and that would not be safe in this case because you only have 3 wire no neutral. There are 220v heaters but I would suggest good insulation on the pipes and letting a faucet trickle so the pump kicks on every 5 minutes or so, I have done this in several homes and not had frozen pipes even in the low single digits and -f but I ...


0

So you have a circuit that seems dead? Confirm whether the lights work - this shows if its a power cut. Check other sockets in the area using a known-good appliance or plug-in tester - this helps identify if its one bad socket or the whole circuit. Locate the breaker box, open, and look for "work in progress" lockout tags. Could be someone is working on ...


2

As a tap to a second building with no sub panel NO It would not be legal. The term tap usually means connecting a smaller conductor to a larger feeder and there are some cases where a tap is legal but not here with the info provided. Maybe it’s legal if this is spliced not tapped if the breaker feeding the 8-3 is 20 amp it probably is ok (they may have ...


1

The 24 volts is probably just induced current because in the MWBC the wires are in the same cable. Andrew said the breakers feeding the circuit were next to each other so they are probably on opposite legs, which is of course correct. The thing he should check is to ensure he has 240volts across the black/red at the first outlet box. If not, the entire ...


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This is a multi-wire branch circuit aka MWBC. This is a special arrangement for delivering two circuits' worth of power onto a single cable with only 1 more copper wire, because it is putting two opposite-pole subcircuits arranged so the neutral only carries differential current. It's quite wire-efficient, but yours was installed quite improperly. They ...


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Looks like a 4 inch square box, probably the 1.5 inch deep 21 cubic inch flavor, with a 2-device mud ring (an additional 5.5 to 8.8 cubic inches depending if it's 1/2, 5/8 or 3/4 deep - it's 1/2, at a guess) Count 1 for grounds, 1 for clamps, 4 for 2 devices, and 10 wires per your diagram (but I see red wires so I suspect some of those cables have 3 wires (+...


2

Your wires and devices need 18x2.25 = 40.5 cubic inches. What you have there is a 4x4 square metal box. If it's 1-1/2" deep it'll be 21 cubic inches. Otherwise I'd expect to see a cubic inch number stamped onto it. There's also a 2-gang mud ring of, well, it sure ain't 19.5 cubic inches! Note that the mud ring does not come all the way out to the wall ...


3

Wow, that much weather damage already to the labeling. Is this door being left open, or did Square D really oversell the NEMA 3R claim? Yes, I agree. This is a special panel specifically for solar. The solar breaker (up top) is bot part of the main bus, and gets its own connection hot-off-the-meter, as does the (notably, factory paralleled) main breaker. ...


6

Yes. The panel's labeling means exactly what you think it means, that breaker slot 5-6 and all above it are limited to 70A breakers max. That 100A breaker should be moved down to the bottom slot. Additionally, that top breaker is being backfed by your solar setup, correct? In that case, it needs to be bolted down -- that's a code requirement whenever a ...


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It's a rating. Like tires. Go shopping for tires. Almost any tire these days is rated 112 mph. *You're allowed to drive 65 on those, it is saying don't exceed 112 mph*. It's the same with subpanels: The "100A" is a maximum rating. Do not exceed 100A. However, you certainly should exceed your feed-breaker size of 50A. Even if 50A panels existed, ...


2

50A is not a standard panel size, you will find a few more options if you search 60A. You can use a panel rated for higher than the feeder, the panel rating is the maximum current allowed. You may wan't to consider checking your wire size, the instructions for the last hot tub I installed specified #6 wire, most of the time #6 can be protected at 60A. (...


3

Using a larger sub panel will not be a problem but the breaker must stay a 50 AMP in the main panel. You can utilize the 50 Amp breaker in the hot tub panel as a connection point for the new wire run or just use that junction as a splice point. If you do that, I don't think you can double lug the wires and would have to use split-bolt connectors (buy a lot ...


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Just wire it up. There is no problem using a sub panel that can take more current than you will ever feed it. Points to note: The cable to your hot tub will be rated for 50A (not 100A); therefore you must not upgrade the breaker in your main panel to 100A. It would be sensible to add a note near the main panel that the cable is only rated for 50A, so not ...


4

With this type of panel, you do not need to disconnect the house via the main breaker. It's OK to leave the main breaker on, and the rest of the house on utility side - however there will be surges when the power comes back. This type switches over each circuit independently, which is a feature I don't ever see needing. Why would you have some on utility ...


6

Each switch has 3 positions, as labeled on the right hand side of the panel: GEN OFF and LINE. In their current position, the normal electrical feed is going to each circuit. If you move the switch to 'GEN' it will then take power from the generator. OFF lets you kill the circuit entirely (connects to neither line nor generator). If the panel was properly ...


0

I just installed a nest on an oldish furnace. If you read the documentation from Nest its says "it draws power from the leads leading to the furnace by briefly turning the furnace ON and OFF faster than the furnace is capable of registering. .... In most cases. However, in my case I had to run additional wires so I could hook it to a 24v transformer ...


1

Your rationale is faulty, but your conclusion is lucky. Normal or provisioned load figures cannot be used as an excuse to not put proper overcurrent protection on a wire. Breakers are for abnormal operation. Normal/average operation cannot be your only defense against overload. Your main breaker needs to be sized to protect the service entrance wires. ...


2

Go 60A on the Tesla charger. You'll thank me later. Your main panel has the capacity for it, so let's just bite the bullet and do it. You can serve it out of the main panel without any trouble. 6/2 cable and you're done. If you want, instead, you could replace that 90A cable with a 150A cable. At that point you can put the 60A charger in the big ...


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If you want to re-use the existing breakers, then buy another GE panel that is larger. If you want all new, anything will do. Note however that if you do this right and get a permit, you might end up having to follow current code rules, which you may find undesirable 9AFCI breakers).


3

Your ambitions exceed your abilities... and there's a lot of problem scope you haven't really thought through. Don't reinvent the wheel First, really, seriously scour the market for existing consumer products which might provide an API. I'm seeing good signs that several consumer home power monitors can provide raw data streams. For instance neurio ...


5

This is probably a matter of not knowing where your service panels are. Plural! Find the meter and follow You need to "follow it from the meter" as it were. Find the meter; easy. Then you'll have one of three things: Additional compartments in the meter cabinet that open up (do not break any seals). Very obvious conduit to another equipment box ...


1

The transformer(s) that power hvac systems have a primary winding that is 120v in most U.S. cases (some are 240). These are controlled from the service panel or a sub panel. The secondary side of the transformer is normally 24vac I have seen 6v to 32v systems all considered low voltage on the secondary the transformer primary is powered in most systems If ...


14

There are two very different issues here: Power to the Thermostat I flipped off all the circuits in the fuse box, and the thermostat on the first floor powered off. However, the thermostat on the second floor still had power. A thermostat is typically powered primarily by a transformer. However, many thermostats include battery backup. There are a ...


6

Thermostats get power from a low-voltage transformer that is either inside your air handler or very close to it. That same transformer also powers the circuit boards and controls of the air handler. That transformer, along with every other electrical device in the house will be connected to a breaker. If you turned off all the breakers and one thermostat ...


1

I generally prefer to do property improvements just once in my lifetime. So I'd bury a pair of generously sized schedule 80 pipes below the frostline (using sched 80 instead of normal sched 40 means I can drive heavy vehicles over them - I have a 900+ lb garden tractor), I'd run them in a dead straight line, and I'd put pull strings in them so I could run ...


39

Why bury a cable when you can be future-proof? The primary issue with direct buried cables is that you have to dig them up in order to upgrade them, a costly proposition. Hence, it's a far better choice to spend the money to lay a couple of fat PVC conduits now and then pull wires through them, than to have to dig things up 5 years down the road because ...


4

If you go small - a single 20A multiwire branch circuit - you don't have to put a subpanel in at the shed. You will still want a disconnect, but they are cheap. At 100', 12/3 UF would do it. But then again, if you spend a few extra bucks, you could bury 8/3 UF instead of 12/3, and use it for that 20A multiwire branch circuit now, and have an easy ...


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I'm going to be a bit contrarian and say 10/3 UF. It's pricier and overkill for your existing setup, but here's why it could be worth doing it now. A single 12/2 means you only get 20 amps at your shed. Period. Next year, you buy some power tools and you start taxing your 20 amp. If the breaker pops, you get to walk back to your main panel. Pop it multiple ...


4

Don't get electrical advice from plumbers. Quite possibly When you calculate the burden the loads place on the panel, that is called provisioning. You don't provision every circuit for its breaker trip value, but rather for a lower number that reflects the probability of it being active at the same time as other loads. A typically reasonably-electric ...


10

I've built several such sheds, and a #12 UF-B (moisture and UV light resistant) cable (usually gray) is appropriate on a 20A breaker (or smaller). Depending on where you are it may need to be buried to a particular depth. Conduit is a good idea and may reduce the depth requirement. Otherwise, use your best judgement to prevent damage in the future. Because ...


-1

Christine (and others viewing this thread), I am sorry to hear about you electrosensitivity. This thread has many well-meaning, but uninformed replies. The best answer I can give you is that you should engage a Building Biologist that is certified for Electromagnetic Radiation. This would not be inexpensive, but would lay out your options plainly and ...


3

It looks like you have a 100 amp service. You cannot figure out what the load is by adding breakers. I am glad you don’t have stab lock breakers I think. Can you add an air handler? Maybe, possibly what size is it??? Can you add a water heater ? Possibly most require a minimum of 30 amps some up to 125 that I have installed in that case not without an ...


1

You have a 100A service, based on breaker below meter. The minimum size allowed is complicated formula from the NEC, there are online worksheets. Some jurisdictions make you recalculate when you apply for a permit to add load, it's a local policy issue.


0

It's a "Meter/Main" panel, it also has a "Split Bus", probably because the upper section is the main house and you have a separate unit, an out-building with a sub-panel and/or sport court lighting on the property fed off of the 3 lower breakers. Nothing illegal about this from what we can see here. The one wire that appears to be aluminum might be an older ...


3

Your breakers are on the hot side , from your description your neutral was connected to one of the hot wires underground. Your ground rod or grounding electrode system must be at a fairly high level. I have seen 2 ea 10’ ground rods have over 100 ohms code allows 1 rod if the value is 25 ohms or less and no measurement is required when you have 2. When the ...


6

ThreePhaseEel, as usual, blew my mind with a notion that the below trouble might not even be at your house, but rather, a neighbor's. This neighbor is sending dozens of amps from his house to the pole transformer, and your house happens to be along that route. So it's trying to hop on your Grounding Electrode System, your cable TV hookup, and your neutral-...


17

I think the power guy's assessment was spot-on He said it appeared that the buried cable coming in from the street had degraded or been damaged and that the "hot must have nipped the neutral." What was happening is that the incoming hot probably contacted the ground indirectly via the insulation failing in some fashion. Your neutral bonds with the ground ...


1

Big enough subpanel That's a 20-space panel. The 40 number is baloney. I'm glad you're getting a good size panel though However, that panel has HOM's super-cheap 100A busing, which forecloses any possibility of going 125A at another time. A panel that size should have 150A+ busing, man, Homeline lives up to its name. Consider also CH, BR, or Siemens. I ...


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