On Sun, 15 Sep 2019 17:20:10 -0400, wrote:

On Sun, 15 Sep 2019 04:44:18 +0000 (UTC), danny burstein
wrote:

In writes:

On Sun, 15 Sep 2019 03:14:01 +0000, Bud Wilder
caedfaa9ed1216d60ef78a6f660f5f85_14498@example .com wrote:

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.

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.

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.



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.
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 - - -