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lee676

How to fuse 220V/!5A device on 220V40A circuit

lee676
14 years ago

Hi, I live i an apartment with only a scant 100A elecrical service available. Much of this is allocated to a 40A loose recepticle behind the kitchen stove, evidentually placed there thinking it would surpport an electric oven or compact stove. But a gas stove is installed there instead, and the 220 circuit (which is live - I tested it) goes unused.

I've given some thought to running the 220 line into the adjacent bathroom annex to use for a washing machine, specifically one of the several 220V/15A front-loading washers that quickly heat their own water and don't draw from the water heater tank. My only qualm is how and where to fuse the circuit so it allows a 220V/15A to trip at 16A, not over 40A. Some devices with two fused 220V/15A outlets that plug into a 220V/30A dryer outlet are available for this purpose (the paired compact dryers also run on 220V/15A), although these are hard to find sometimes. Or I could just put an electrical junction box somewhere along the way with a fused 15A outlet on it. I suppose there's the option of replacing the 220/40A circuit breaker with a 220/15A one,, but this will require shutting down electricity for two other apartments, something I'd prefer to avoid, and the wiring would be unnecessarily thick gauge.

How best this be done? I favor the first approach, adding a fuse or circuit breaker in line, but where and what type of fuses of circuit breakers would I need? All I see at the big box store are circuit breakers made installing in a panel, old-fashioned screw-in fuses, Buss type in-line fuses with holders, and such. Some specify amperage but not voltage - are these devices ok for 220v use (I'm aware we're dealig with two hot wires, a neutral, and a ground here, and I don't want to trip only one phase of a split-phase circuit.) I'd want be safe and up to code, if not necessarily conventional.

What do you suggest? Thx.

Comments (22)

  • brickeyee
    14 years ago
    last modified: 9 years ago

    "Much of this is allocated to a 40A loose recepticle behind the kitchen stove, evidentually placed there thinking it would surpport an electric oven or compact stove."

    The sum of the protection devices has nothing to do with load calculations.

    Apartment building wiring must be performed by a licensed electrician, so contact one and let than advise you on how to proceed.

  • pharkus
    14 years ago
    last modified: 9 years ago

    I'm gonna make some corrections first, then partially answer you.

    My first peeve is your reference to a "scant" 100A service. Even if you HAD an electric stove, you would not be using it 24/7, and thus, the 40A "allocated" to it would normally be available for other things.

    A 15A breaker does not "trip at 16A". There is a delay. The larger the overcurrent, the shorter the delay. A 15A breaker will actually "trip at" 15A, given a long enough time to do so.

    Now, for "up to code"... If you want it to be legal, don't touch it. In most cases, you can do your own electical work, but only in a single-family dwelling which you own and occupy. You cannot, anywhere I know of in the USA, DIY an apartment building.


    That said...

    I haven't seen any recently-manufactured "inline" breakers or fuses as you describe -- ie, no "fused receptacles".

    Assuming you truly have a four-wire feed there, what you need to do is install a 'subpanel' - which can be a simple two-space disconnect, containing your smaller breakers.


    My PERSONAL solution in this case, and I believe this to be legal in your case, would be to install a 15A DP breaker in a box on the back of the machine itself, then feed it with a 4-wire "pigtail" (cord) matching the existing receptacle -- ie, continue the 40A all the way to the machine, then protect it there.

  • jmvd20
    14 years ago
    last modified: 9 years ago

    Aside from the fact that you must be licensed to touch wiring in an apartment I would also venture a guess that the owner might not be too fond of someone installing a washing machine either.

  • brickeyee
    14 years ago
    last modified: 9 years ago

    "A 15A breaker will actually "trip at" 15A, given a long enough time to do so."

    A 15 amp breaker should never trip at 15 amps. That is what it is rated to pass continuously.

    Tolerances will mean that a few in any lot may trip barely below 15 A, but nearly all will carry it indefinitely.

    The inverse time curve is created by using a thermal and a magnetic trip in the same breaker.
    The thermal produces a lag in tripping till a little over 450% of rated current. At this point the trip time falls to milliseconds under the magnetic trip.

    Like everything else, there are tolerances on the values, but they are measured and controlled to maintain safety.

    Here is a link that might be useful: Circuit Breakers

  • lee676
    Original Author
    14 years ago
    last modified: 9 years ago

    Thanks for your responses... a few clarifications:

    * First, sorry about all the typos - don't know what I was under the influence of when I wrote the OP... probably tiredness.

    * I am aware that electric power isn't "allocated" to any particular outlet, circuit, or device, and that if everything were powered on at once it would probably trip everything in the box. Likewise the nature of how circuit breakers trip. Poor choice of words but I understand the underlying concepts of slow-blow fuses and such. I just meant to emphasize that there was an unused 240V circuit that could potentially be used for another appliance without the risk of running the laundry and stove off the same circuit.

    *I rent, but it is a semi-detached house (duplex) and I'm the tenant.

    > I haven't seen any recently-manufactured "inline" breakers or fuses as you describe -- ie, no "fused receptacles".

    I have - they're fairly common; Miele has sold them for years. Here's what another brand looks like:

    {{gwi:2099256}}

    {{gwi:2099257}}

    {{gwi:2099258}}

    {{gwi:2099259}}

    As you can see, the box has two 240V/15A outlets, each with its own circuit breaker switch, and the whole shebang plugs into a 240V/30A outlet (the type commonly used for North American clothes dryers). The intent is to make it easy to replace an old one-piece stacked washer/dryer unit (a top-load washer with an electric dryer built in above it, which has a single 240V/30A cord) with a separate front-load washer (of the type I'd like to use) and a separate dryer, both machines being 240V/15A, thus not requiring any electrical work to install the new machines.

    If my existing unused 240V outlet was on a 30A rather than 40A circuit, there wouldn't be an issue here. Just plug the washer into the splitter box, shut off the circuit breaker for the second, unused 240V/15A outlet, and plug the box into the wall outlet. But as it is, I would need to convert the splitter-box plug from a 30A plug to a larger 40A plug to mate with the existing 40A outlet. As far as I can tell, this doesn't introduce any risks since the only device(s) that can be plugged into it are still individually fused at 15A at the splitter box.

    I could attach a full box with a 15A DP breaker as Pharkus suggests too - does the box have to actually be attached to the machine, as opposed to mounted on/in a nearby wall?

    As for the owner not being too fond of a tenant installing a washing machine, he probably isn't, but I read through his lease form carefully and though he expressly prohibited waterbeds, water-filled furniture, aquariums, and tampering with faucets, it makes no mention of laundry appliances. (FWIW, it's also full of illegal verbiage that would land him in hot water with HUD and/or fair-housing laws, like not allowing children as tenants. The building is also badly miswired and plumbed and fails to meet code in many areas).

  • brickeyee
    14 years ago
    last modified: 9 years ago

    "each with its own circuit breaker switch"

    Are you sure those are circuit breakers?

    One of the reasons circuit breakers are as big and 'chunky' as they are is to ensure enough spring energy is available to force the contacts to open when tripped.

    That is why the effort to close a breaker is so much less than tte effort to open one.
    You are cocking the trip mechanism.

    That is also cord and plug connected equipment, and is not subject to the same rules as permanent wiring.

    You are a tenant in a multi-family building.
    Almost every jurisdiction prohibits you from doing electrical work.

    In single family housing it is only you and yours at risk, not so in multi-family.

  • pharkus
    14 years ago
    last modified: 9 years ago

    Alright. I'm not 100% confident the device you show is actually fused or contains breakers, but if it does, it'll work, and you are correct, that there is not a safety risk created by replacing the 30A plug with a 40A plug, as long as the two receptacles are still individually protected at 15A.

    You could build the same box.

    My suggestion of attaching your breaker-containing disconnect box to the back of the washer was based on the idae that, in order to do a neat and safe job, you've gotta attach it to _something_. If it's hardwired to the washer (which was my original suggestion), it seems most sensible that it be attached in such a way that it moves WITH the washer. If you pull out a plugged-in appliance without unplugging it (which you should NEVER do anyway), 9 times out of 10 it'll just pull the plug out of the socket. Not so if the appliance is hardwired to a breaker box - it'll rip the wires out of something, and there could be a light show, possibly pyrotechnics. Safer to just physically attach them together.

    If course, you could just use a receptacle to allow the washer's original plug to connect to - in which case you're basically building your own version of the box you showed...

  • lee676
    Original Author
    14 years ago
    last modified: 9 years ago

    OK, here's another version of this device made by another company:

    {{gwi:2099260}}

    This one was sold recently on eBay with this description:

    ------
    * Miele washer/dryer Easy Connect Kit NEW

    * Description: Miele Easy Installation Kit. Used to connect 220/240 volt Miele washer and dryer to a single dryer outlet.

    * Designed for use with Miele washer series W1800 and W1900, for example W1918 or W1930
    * Designed for use with Miele dryer series T1400 and T1500, for example T1520
    * Plugs into a 4-hole dryer outlet (NEMA 14-30R).
    * You then plug both your washer and your dryer into the box. The box has two 4-hole outlets (NEMA 14-20R).
    * Cable from the plug to the box is about 50" long
    * Mounts directly to the wall with two screws (screws not included)
    * Has replaceable fuses, type 3AB, 15Amp
    * Serial #: 980087-34
    * Model - US 30 Amp
    * 120/208V 120/240V, 30A
    * From the Miele instruction manual for my washer (W1918): * "EASY INSTALLATION KIT - If you ... have a 4 wire, 240V (208V), 30A line, you can use an optional “Easy Installation Kit”, which will allow you to connect this appliance to that line."
    -----

    So from this I think we can deduce:

    a) the two outlets on the box are indeed individually fused (in this case, at 20A each, even though the box still plugs into a 30A outlet)

    b) it is designed to be mounted to a wall, not to the washing machine

    As for doing electrical work in a multi-tenant building, I have to assume the availability of these "easy installation kits" would indicate that their manufacturers don't consider installing these boxes to constitute "electrical work", and that their installation is intended to be done by consumers, or at least appliance-delivery guys, not electricians.

    If so, then would building my own box as Pharkus suggested be considered "electrical work"? I'm not doing anything to the building's wiring or devices, just plugging stuff in.

    My concern with attaching the box to the washing machine (beyond lack of space in the area) is that washers can shake and move occasionally during the spin cycle, and I thought a remote wall-mounted box would be better protected from being crashed into or splashed on. That is what this manufacturer (Miele) suggests in their instructions (thus the 50" cord).

  • lee676
    Original Author
    14 years ago
    last modified: 9 years ago

    (correction: the outlets are fused at 15A not 20A, even though this one uses NEMA 14-20R outlets, the type rated for 240V/20A.)

  • brickeyee
    14 years ago
    last modified: 9 years ago

    Since the box is cord and plug connected it is not permanent wiring needing a permit and inspections.

    "I've given some thought to running the 220 line into the adjacent bathroom annex to use for a washing machine... "

    Running a new line as described here IS permanent wiring.

    If you can plug in the box and the cord is long enough you might be OK, but the cord cannot run through walls.

  • lee676
    Original Author
    14 years ago
    last modified: 9 years ago

    Although running a cord through the wall would be the shortest distance, the cord could be routed around it and that way would not go through a wall. The aforementioned bathroom annex is a nook near a laundry tub with no door, so the box cord (when combined with the washer's own cord) would not involve "running a line" in the sense of Romex-type permanent wiring. If the cord couldn't reach, I could (I assume) use an extension cord of the type made for window air conditioners (the thick ones designed for high amperage), therefore retaining all-temporary electric cords. The washer itself is designed for (optional) portable installation - a temporary sink attachment is available from the manufacturers, as are caster wheels for the washing machine, so it's clearly designed for temporary/portable use.

    This is a basement apartment where the "walls" in this area are actually thin partitions that don't reach all the way to the ceiling (or to the permanent wall in one case). I'm not sure whether these are considered "walls" by the NEC, but by routing the cords outside and around these partitions I can avoid any ambiguity.

    Many of my apartment neighbors have a rat's nest of extension cords plugged into the few wall outlets, sometimes with cords squashed by furniture legs or buried under debris. I can't believe what I want to do isn't safer than that arrangement. I suppose if need be, I could hire an electrician to install a new circuit or revamp the existing one. This may violate the lease agreement, but not the NEC as far as I'm aware. Since I pay the electric bill, this would have no negative consequence to the landlord - I would essentially be improving his property at my cost. I suppose I could seek approval from the landlord to hire an electrician for some upgrades (and repair of the existing miswired outlets while they're at it). But I'd like to avoid getting an electrician involved if at all possible, especially since it seems I can legally and safely accomplish what I'm trying to do on my own.

  • brickeyee
    14 years ago
    last modified: 9 years ago

    "If the cord couldn't reach, I could (I assume) use an extension cord of the type made for window air conditioners (the thick ones designed for high amperage), therefore retaining all-temporary electric cords."

    Using temporary wiring in place of permanent wiring is an NEC violation, but it sounds like you already have a fire trap from the neighbors.

  • lee676
    Original Author
    14 years ago
    last modified: 9 years ago

    > Using temporary wiring in place of permanent wiring is an NEC violation

    So using a household extension cord sold at every grocery store and Home Depot to plug in a household appliance is a NEC violation? That's all I'm talking about here - plugging a portable appliance into an extension cord rated for its amperage, and plugging that into an existing outlet.

  • kensnh
    14 years ago
    last modified: 9 years ago

    Judging by your responses here, you are trying to convince us that this is legal and safe. I WILL NOT SPEAK for others on this forum, but what you propose MAY be legal, but IS NOT SAFE. Obviously, your EBay research has garnered you enough electrical knowledge to go ahead and continue with this stellar installation. There are many, many reasons why you should not. But you will do it anyway, because, if I can buy it on EBay, it must be safe, right? So God willing, nobody gets hurt, or sued.

    But I will say: It is a BAD idea. For many reasons, and I'm not going to bother to quote Code, or common sense, you'll paste in a link to say "I can buy it, it must be safe!"

  • lee676
    Original Author
    14 years ago
    last modified: 9 years ago

    kensnh, really, if you think it's not safe, I won't do it. However, i do feel obliged to mention that eBay has nothing to do with this - I only referenced someone's EBay auction because the manufacturer's own website doesn't list the specifications and the guy selling the same thing on eBay did.

    But these devices are not devised by random charlatans on EBay, but rather (in this case) built and sold by Miele, a respected and esteemed appliance manufacturer who I assume wouldn't or couldn't sell unsafe merchandise. I wasn't actually planning to buy this on eBay, but rather directly from Miele or Bosch or their authorized retailers, and if need be have them drive out to my home and install it.

    The only thing different about my situation than that of a typical buyer is that instead of a 240V/30A outlet near the dryer, I have a 240V/40A outlet about 10 feet away. I thought, maybe, there would be some safe, legal way to use that to power a laundry appliance since it is currently unused. But if not, I can continue to use the more common 120V/15A washer I have now that plugs directly into the nearby outlet. It doesn't heat its own water and draws from the water heater tank, but I can continue to avoid using the washer and the shower at the same time.

    FWIW, I don't like using extension cords either. I'm very careful with the ones I do have - they're not dangling where they can get tripped on or squashed or have things fall on them.

    But I *do* tend to believe that if a respected major company sells something, it's probably safe. Not always, obviously.

  • geovann
    14 years ago
    last modified: 9 years ago

    * Cable from the plug to the box is about 50" long
    That is 4'2" a long way to go. Look at extension cords on your typical kitchen appliance. 4'. You do the math.
    I am sure if you look up the "Listing" no matter what Company "Listed" this cord or appliance. Sounds like if the box was manufactured with a 50" cord thats all you get.
    I have never seen a cord "Listed" to go through any framed wall.
    Granted rats nests are eveywhere. But two wrongs dont make a right.

  • brickeyee
    14 years ago
    last modified: 9 years ago

    "That's all I'm talking about here - plugging a portable appliance into an extension cord rated for its amperage, and plugging that into an existing outlet."

    If the appliance is going to remain in the same location and not actually be moved from place to place then using an extension cord would be a violation.

    If you unplug the cord and move the appliance between uses (typical for an actual portable appliance) it would comply.

    Cords are for temporary use, not permanent.

  • User
    14 years ago
    last modified: 9 years ago

    And of course none of the posters have one of these being used
    permanently in their home. ;-)

    Here is a link that might be useful:

  • lee676
    Original Author
    14 years ago
    last modified: 9 years ago

    > If you unplug the cord and move the appliance between uses (typical for an actual portable appliance) it would comply

    I'm not sure what the deal is with "portable appliances" - I don't think even most small appliances like blenders or toasters get moved around alot, much less refrigerators or washing machines. Yet a quick glance at General Electric's website shows they sell "portable" dishwashers, clothes washers, and dryers. The first two have wheels so you can move them around if you want. The dryer doesn't have wheels, and I wonder how many people actually move their dryers back and forth each time they use them (they weigh 87 lbs. by the way). It's as if they make these things for people who want to skirt some sort of installation requirement for non-"portable" appliances or something, not sure what. The owner's manual does say not to use an extension cord though.

    And yes, I've noted that surge protectors and power strips are always labeled "temporary power tap" on the underside. I'm sure these are never left in place for years at a time either....

  • brickeyee
    14 years ago
    last modified: 9 years ago

    "I'm sure these are never left in place for years at a time either...."

    That is actually not related to the argument if it is a violation to use devices this way.

    Many large companies try to enforce policies about using 'power strips' as permanent wiring.

    Surge suppressors are not in the same class, since they provide a function besides just additional receptacles.

    'Portable' is in the eye of the user, and using an extension cord to power up a portable item that is used in the same location gets into a touchy area.

  • Billl
    14 years ago
    last modified: 9 years ago

    While there is certainly an economic incentive to skirt code, it usually isn't a good idea. Using extension cords in place of permanent wiring falls into the "isn't a good idea" category. Could you get away with it? Maybe. I doubt an inspector would by your argument, but an inspector isn't going to come unless someone calls him.

  • kensnh
    14 years ago
    last modified: 9 years ago

    Hey, all we can do is try..............

    See my earlier post, I'd bet it's already done anyway.

    Don't ask for good advice if you don't want good advice.

    BYE>