Wiring new 220v circuits into fuse box - links?

Anyone have any good wiring links?

Doing a Google search returns to much junk. I wonder if there are any tip pages people know about for this which are QUALITY, to save hours of time going through bad Google results?

Reply to
StarMan
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If you ask a specific question, you'll get plenty of quality answers right here

Reply to
RBM

Try the reputable sites like This Old House, Hometime, HGTV, as well as the Depot and Lowe's sites, all should have ome content available, probably Pop Sci / Pop Mech as well. Or go to Depot, Lowe's or your local library (yes libraries still exist) and get a basic home wiring book.

Reply to
Pete C.

The short answer is probably "you can't do it without a service upgrade". If you have a spare "pullout" it is easy but that is unusual on an old fuse panel.

Reply to
gfretwell

According to :

I think "pullouts" in this context are double fuse blocks that plug into the fuse panel backplane. Those designed for a 240V circuit have hinged interlocking covers on them on them that prevent the fuses being unscrewed without removing the whole "pullout", so both sides of the circuit are dead. The fuses in pullouts designed for 120V circuits can simply be unscrewed without removing the block, and these blocks are intended to be left in the panel more-or-less permanently.

We kept some spares of both types when we wired a cottage back in the early 70's ;-)

If you don't have a spare, it's still usually possible to obtain one - either at a proper "electrical supply" place, or at fleamarkets.

Not all fuse panel types have pullouts, and those that do don't physically _have_ to have "interlocking" pullouts installed for 240V.

Putting 240V into a panel without an interlock of some sort between the legs is _usually_ a code violation. Heck, an anal inspector might even insist on upgrading to circuit breakers.

If you want to do this and stay code-legal, best to consult with a local inspector or an electrician. Regardless of whether you want to keep this code-legal, the fact that you're asking this question at all, suggests you should engage the aid of an electrician.

Reply to
Chris Lewis

Fuse boxes are now obsolete and some insurance companies are requiring their replacement. Plus new service gets you up to date grounding. Rather than spend money that might be wasted a better investment may be a service upgrade.

A real positive at home resale time too!

Reply to
hallerb

That's not always the case. Sometimes one just needs a reference to make sure one is SURE to be doing it RIGHT.

Asking a question isn't the same as "don't have a clue". LOL

Reply to
StarMan

I confess I stated it poorly. I know I'm going to get chastized for it, too LOL

I have been in the habit of calling all "breaker boxes" "fuse boxes". It's just a habit I got into from growing up in a house with a FUSE box. Fact is, I have a breaker box in this house, less than 20 years old.

I already have numerous 120v circuits and a couple 240v for the heat exchanger and the stove. I have enough space for the addition of 2 more double-breakers in this box. I just want to make sure I wire them up properly.

Reply to
StarMan

At this point I'd really just like to see a diagram of how a 220v is wired into a breaker box. I understand it conceptually but I want to understand thoroughly so I don't have any problems.

I may have more specific questions once I see the diagram :-)

Reply to
StarMan

As a general rule, every other slot is on opposite phases so when you plug in a 2 pole breakers you get 240v. Just don't confuse a 2 pole breaker with a piggy back breaker that only takes one full slot and gives 2 120v circuits. There are a few panels out there (old GEs for example) that have a strange bus wiring but these are fairly rare..

Reply to
gfretwell

According to StarMan :

Agreed, that's not always the case. I often ask here about things I understand, and just want to find out a preferred method or specific suggestions about something a bit unusual.

For example, I'm replumbing our bathroom - moving all the fixtures and adding one, and the system has some restrictions. I have a good book on plumbing, and have done lots of smaller plumbing jobs before. But there's a few places where I might ask for a hint/suggestion on situations that don't quite line up with the book.

Eg: in one situation regarding venting. Strict code compliance/ inspector might require upsizing (or adding) a vent from the basement to the roof of a 2 story house. I'm only one foot (horizontal drain length) and one vent "fixture unit" (FU ;-) short of not needing additional venting at all by the code table.

Part of the drain is larger than the code table, and hence the table is being too pessimistic. The fixture is much lower flow than normal, so I'm not really one FU short either. There's already considerable margin in the code requirements.

Installing a vent would severely impact the size of the whole project (it already includes re-drywalling half of the bathroom, installing a pocket door in a new wall, and installing a shower stall.) and I don't think it's necessary.

Will it work? Dunno yet. I think so. But I've not asked the question in enough detail yet.

However, asking a question in such way that indicates that the person doesn't understand that aspect of wiring at _all_ does imply that perhaps they should stay away from it. Or, get a good book on the subject and read/understand it first.

I'm pretty judicious as to when to make those suggestions. This seemed a good candidate.

Reply to
Chris Lewis

According to :

Right - some FPE panels too. Aside from those oddballs, a double breaker will work no matter which pair of slots you jam it in.

If in doubt, install the breaker, and use a voltage tester across the terminal screws on each breaker. If it's zero volts, it's the kind of panel where it does matter, and you have the breaker installed wrong. If you see 240V, either it doesn't matter, it does, and you were lucky the first time.

He's asking for more than that. He also has to identify whether it's a pure 240 circuit or a 240/120V circuit.

If it's a pure 240V circuit, he'll be using /2 wire (two insulated conductors and a ground, often black, white and bare, tho, red black and bare is available and somewhat preferrable). Each of the insulated conductors goes to one half of the double breaker, and the bare (ground) connects to the ground bar.

If it's a 240V/120V circuit (stove, dryer, split duplex receptacle string), he'll be using /3 wire. Red to one breaker. Black to the other. White to the neutral bar, and bare to the ground bar.

Leave extra slack in the wires. Use the clamps properly (you will probably have to use a new clamp in a new hold - doubling up is somewhat frowned upon)

Caution: I briefly tried googling for a simple diagram, but the only one I found, on a self-proclaimed "do it yourself" site, had it wrong. [Weren't properly segregating the ground/neutral wires.]

Sheesh.

Reply to
Chris Lewis

replying to RBM, Bud Wilder wrote: I am installing a new electric hot water heater in a home that was built in

1936. The fuse box is the old conventional type, not circuit breakers. Please direct me as to how to connect the wire running from the 220 v plug directly to the existing fuse box.
Reply to
Bud Wilder

Probably can't be done. Is there a 30a pull out that is not being used? Other than that there is no legal way without doing something with that box.

Reply to
gfretwell

FIrst, if you're asking the question in this manner, chances are you really should NOT be even thinking of dealing with wiring into a fuse box.

That being said, if you're more familiar with electricity than your simplistic post suggested, there is a _possible_ alternative you might be able to use.

Now... IF... you're talking about the US (or Canada) where the standard voltage is 120, and to get 240 (you said 220, but that's a common issue), you have to do some modestly but common (in _newer_ homes) trick stuff, there's another option, maybe, for you.

How much hot water do you actually use, and how quickly do you need more?

The reason: The 240V water heater will warm up the water sitting in the tank (how large is it?) and keep it hot until used. Then... it will take the new, incoming, and cold water... and heat it up.

This "recovery rate" is based on the wattage (plus the incoming temperature, etc).

Now... you (if you really know what you're doing) can rewire that 240V water heater so that it runs off "only" one of the 120V legs.

This will significantly reduce the recovery rate, that is, it will take a _lot_ longer to heat up that big tank of cold water. [a]

However, if you have a large enough tank and don't pull too much at a time, and don't need a hefty second chunk too soon, it might work out.

[a] you'd at first think that reducing the voltage by half means twice as long for the hot water, but it's actually four times the duration.

Reducing the voltage by half _also_ reduces the amperage going through by half, so the actual wattage (voltage times amps) is cut by 3/4 [b]

[b] there are some modest additional variables due to the temperature swings, but they're lost in the noise.
Reply to
danny burstein

Lighten up Danny I answered the question. The OP is talking about how you add a 30 amp circuit I am assuming he has an old split bus panel with one to 4 pullouts (the big black thing with a handle).

If he has that, there is a very good chance he doesn't have a circuit that can take another kilowatt from a rewired 4300w water heater anyway.

Even if he does have a somewhat modern "Woodstock era" fuse panel with a main breaker (and SqD made a 200a one), he still needs a spare pullout. Them's is just facts.

My bet is he gets a service upgrade or the water he is heating may be coming from fire hoses.

Reply to
gfretwell

How many fuses in the box? What amperage main? Many of that agec cannot support a water heater (65 amp main was BIG in 1936.)

Reply to
Clare Snyder

Correct. The addition of an electric water heater, range, drier,or air conditioner is the "tipping point" for MANY service panel replacements.

1936 homes were not wired for today's conveniences - even IF our lighting consumes only about 70% of what it used to for the same amount of light - and our Radios (and TVs) consume much less power. I remeber a lot of houses that only had 2 fuses - - - and many more that only had 6, with one "pull-out" for 240 volts. My 1974 house had 2 pull-outs for cartridge fuses (stove and drier) but ganged pullouts were available for plug fuses as well. Still only about 8 circuits though - - -
Reply to
Clare Snyder

A related question would be what was heating the water before and why not stick with whatever was fueling that?

Reply to
trader_4

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