While working in an older unit, I was helping to track down which fuse
controlled which circuit. The fuses were in a closet, in two separate fuse
boxes. These were the screw in/screw out fuses.

There were several porcelein fuse holders and each contained 2-4 fuses. I
unscrewed one fuse and noticed that the ceiling light in the bedroom went
out. However, when I unscrewed the other fuse in the porcelein fuse holder
(there were two) the same light went out. The same thing happened for the
light in the closet.

Why would two fuses control the same light?

The porcelein fuse holders were a 4" square block for those that held two
fuses. Wires went into the back or sides of the fuse holder.

Oh, also, the wiring looks to be 12 or 14 ga (cloth covered, older wire so
it's hard to tell), and the fuses are all 30A. I'm assuming I should
mention this to the owner and mention that he should get the correct sized
fuses in?


--
charles

"Charles Bishop" wrote in message
...
While working in an older unit, I was helping to track down which fuse
controlled which circuit. The fuses were in a closet, in two separate fuse
boxes. These were the screw in/screw out fuses.

There were several porcelein fuse holders and each contained 2-4 fuses. I
unscrewed one fuse and noticed that the ceiling light in the bedroom went
out. However, when I unscrewed the other fuse in the porcelein fuse holder
(there were two) the same light went out. The same thing happened for the
light in the closet.

Why would two fuses control the same light?

The fuses are wired in series. Strange!

The porcelein fuse holders were a 4" square block for those that held two
fuses. Wires went into the back or sides of the fuse holder.

Oh, also, the wiring looks to be 12 or 14 ga (cloth covered, older wire so
it's hard to tell), and the fuses are all 30A. I'm assuming I should
mention this to the owner and mention that he should get the correct sized
fuses in?

Yes, sounds like a fire just waiting to happen.

Charles Bishop wrote:
While working in an older unit, I was helping to track down which fuse
controlled which circuit. The fuses were in a closet, in two separate fuse
boxes. These were the screw in/screw out fuses.

There were several porcelein fuse holders and each contained 2-4 fuses. I
unscrewed one fuse and noticed that the ceiling light in the bedroom went
out. However, when I unscrewed the other fuse in the porcelein fuse holder
(there were two) the same light went out. The same thing happened for the
light in the closet.

Why would two fuses control the same light?

The porcelein fuse holders were a 4" square block for those that held two
fuses. Wires went into the back or sides of the fuse holder.

Oh, also, the wiring looks to be 12 or 14 ga (cloth covered, older wire so
it's hard to tell), and the fuses are all 30A. I'm assuming I should
mention this to the owner and mention that he should get the correct sized
fuses in?



Many, many years ago, it was fairly common to fuse *both*
the Hot and the Neutral lines. Not considered safe today.

You are probably not in a position to dictate to the
owner what he should do about all these problems. But at the
very least present him with some kind of statement of what was
found, for your own benefit if nothing else.

Jim

Charles wrote:

"Charles Bishop" wrote in message
...

While working in an older unit, I was helping to track down which fuse
controlled which circuit. The fuses were in a closet, in two separate fuse
boxes. These were the screw in/screw out fuses.

There were several porcelein fuse holders and each contained 2-4 fuses. I
unscrewed one fuse and noticed that the ceiling light in the bedroom went
out. However, when I unscrewed the other fuse in the porcelein fuse holder
(there were two) the same light went out. The same thing happened for the
light in the closet.


Why would two fuses control the same light?


The fuses are wired in series. Strange!

Maybe some know-nothing who wired the place put fuses in BOTH the hot
and neutral leads? That'd put them in series, but without a common
connection between them.

Someone with a voltmeter and a little knowledge could sort things out
pretty quickly.



The porcelein fuse holders were a 4" square block for those that held two
fuses. Wires went into the back or sides of the fuse holder.

Oh, also, the wiring looks to be 12 or 14 ga (cloth covered, older wire so
it's hard to tell), and the fuses are all 30A. I'm assuming I should
mention this to the owner and mention that he should get the correct sized
fuses in?

I'm assuming that's what's in there now are standard glass fuses. If so,
I'd strongly suggest to the owner that after ascertaining the gauge of
the wire (by direct measurement or comparison with known gauge wire)
that he/she installs appropriate size non-removable adaptors and
"Fusestat" non-interchangable fuses.


Yes, sounds like a fire just waiting to happen.



Jeff

--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.8*10^12 furlongs per fortnight.

Speedy Jim has hit the nail on the head. There was a time when you could get
screw in shunts to replace the fuses on the neutral side. In any event those
neutrals should not be fused now.




"Charles Bishop" wrote in message
...
While working in an older unit, I was helping to track down which fuse
controlled which circuit. The fuses were in a closet, in two separate fuse
boxes. These were the screw in/screw out fuses.

There were several porcelein fuse holders and each contained 2-4 fuses. I
unscrewed one fuse and noticed that the ceiling light in the bedroom went
out. However, when I unscrewed the other fuse in the porcelein fuse holder
(there were two) the same light went out. The same thing happened for the
light in the closet.

Why would two fuses control the same light?

The porcelein fuse holders were a 4" square block for those that held two
fuses. Wires went into the back or sides of the fuse holder.

Oh, also, the wiring looks to be 12 or 14 ga (cloth covered, older wire so
it's hard to tell), and the fuses are all 30A. I'm assuming I should
mention this to the owner and mention that he should get the correct sized
fuses in?


--
charles

RBM wrote:
Speedy Jim has hit the nail on the head. There was a time when you could get
screw in shunts to replace the fuses on the neutral side. In any event those
neutrals should not be fused now.




"Charles Bishop" wrote in message
...

While working in an older unit, I was helping to track down which fuse
controlled which circuit. The fuses were in a closet, in two separate fuse
boxes. These were the screw in/screw out fuses.

There were several porcelein fuse holders and each contained 2-4 fuses. I
unscrewed one fuse and noticed that the ceiling light in the bedroom went
out. However, when I unscrewed the other fuse in the porcelein fuse holder
(there were two) the same light went out. The same thing happened for the
light in the closet.

Why would two fuses control the same light?

The porcelein fuse holders were a 4" square block for those that held two
fuses. Wires went into the back or sides of the fuse holder.

Oh, also, the wiring looks to be 12 or 14 ga (cloth covered, older wire so
it's hard to tell), and the fuses are all 30A. I'm assuming I should
mention this to the owner and mention that he should get the correct sized
fuses in?


--
charles





Well, I've learned something new again in this thread. When I posted my
first reply I thought for sure that neutrals were NEVER intentionally
fused, because why would anyone feel a need to do that?

Was there a time when neutral wasn't intentially at at ground potential?

If someone can tell me WHY they felt the need to fuse them "back then"
my curious mind would sure like to learn more.

Jeff
--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.8*10^12 furlongs per fortnight.

On Thu, 26 Apr 2007 16:30:18 -0400, Speedy Jim wrote:

snip

Oh, also, the wiring looks to be 12 or 14 ga (cloth covered, older wire so
it's hard to tell), and the fuses are all 30A. I'm assuming I should
mention this to the owner and mention that he should get the correct sized
fuses in?

snip

You are probably not in a position to dictate to the
owner what he should do about all these problems. But at the
very least present him with some kind of statement of what was
found, for your own benefit if nothing else.

Jim


What do you think he meant by "I should mention this to the owner?"

On Apr 26, 7:04 pm, Terry wrote:
On Thu, 26 Apr 2007 16:30:18 -0400, Speedy Jim wrote:

snip



Oh, also, the wiring looks to be 12 or 14 ga (cloth covered, older wire so
it's hard to tell), and the fuses are all 30A. I'm assuming I should
mention this to the owner and mention that he should get the correct sized
fuses in?

snip

You are probably not in a position to dictate to the
owner what he should do about all these problems. But at the
very least present him with some kind of statement of what was
found, for your own benefit if nothing else.

Jim

What do you think he meant by "I should mention this to the owner?"

Anyone have the thought that one of the fuses may have been the "main"
and the other fuse the "circuit"?


JK

Not necessarily, if the service was only 30 amp, it was common to have plug
fuses



"Terry" wrote in message
...
On 26 Apr 2007 17:05:32 -0700, Big_Jake
wrote:

On Apr 26, 7:04 pm, Terry wrote:
On Thu, 26 Apr 2007 16:30:18 -0400, Speedy Jim wrote:

snip



Oh, also, the wiring looks to be 12 or 14 ga (cloth covered, older
wire so
it's hard to tell), and the fuses are all 30A. I'm assuming I should
mention this to the owner and mention that he should get the correct
sized
fuses in?

snip

You are probably not in a position to dictate to the
owner what he should do about all these problems. But at the
very least present him with some kind of statement of what was
found, for your own benefit if nothing else.

Jim

What do you think he meant by "I should mention this to the owner?"

Anyone have the thought that one of the fuses may have been the "main"
and the other fuse the "circuit"?


JK

Mains are not screw in. They are pull out type.

Terry wrote:

On 26 Apr 2007 17:05:32 -0700, Big_Jake
wrote:


On Apr 26, 7:04 pm, Terry wrote:

On Thu, 26 Apr 2007 16:30:18 -0400, Speedy Jim wrote:

snip




Oh, also, the wiring looks to be 12 or 14 ga (cloth covered, older wire so
it's hard to tell), and the fuses are all 30A. I'm assuming I should
mention this to the owner and mention that he should get the correct sized
fuses in?

snip


You are probably not in a position to dictate to the
owner what he should do about all these problems. But at the
very least present him with some kind of statement of what was
found, for your own benefit if nothing else.

Jim

What do you think he meant by "I should mention this to the owner?"

Anyone have the thought that one of the fuses may have been the "main"
and the other fuse the "circuit"?


JK


Mains are not screw in. They are pull out type.


Well, not always. I can recall clearly one service
which was rated at 30 Amps 120/240V.
It used 2 plug fuses for the Mains protection and a bank
of 4 plug fuses for the 4 branch circuits (no Neutral fusing).

Much more interesting though was a large branch circuit
panel in an elegant mansion built in 1900. This panel
came off a 3-wire feeder rated at 60 Amps. The interesting part
was that most of the branch circuits used an Edison 3-wire circuit
where the Neutral was shared. BUT.....they fused the shared Neutrals!!
When one of those Neutral fuses opened, the circuit voltage on any
one branch could be anything from near Zero all the way up to 240V !

Jim

Here's on with a non fused neutral:
http://i17.photobucket.com/albums/b9...s/DSCN1829.jpg




"RBM" rbm2(remove wrote in message
...
Not necessarily, if the service was only 30 amp, it was common to have
plug fuses



"Terry" wrote in message
...
On 26 Apr 2007 17:05:32 -0700, Big_Jake
wrote:

On Apr 26, 7:04 pm, Terry wrote:
On Thu, 26 Apr 2007 16:30:18 -0400, Speedy Jim wrote:

snip



Oh, also, the wiring looks to be 12 or 14 ga (cloth covered, older
wire so
it's hard to tell), and the fuses are all 30A. I'm assuming I should
mention this to the owner and mention that he should get the correct
sized
fuses in?

snip

You are probably not in a position to dictate to the
owner what he should do about all these problems. But at the
very least present him with some kind of statement of what was
found, for your own benefit if nothing else.

Jim

What do you think he meant by "I should mention this to the owner?"

Anyone have the thought that one of the fuses may have been the "main"
and the other fuse the "circuit"?


JK

Mains are not screw in. They are pull out type.

On 26 Apr 2007 17:05:32 -0700, Big_Jake
wrote:

On Apr 26, 7:04 pm, Terry wrote:
On Thu, 26 Apr 2007 16:30:18 -0400, Speedy Jim wrote:

snip



Oh, also, the wiring looks to be 12 or 14 ga (cloth covered, older wire so
it's hard to tell), and the fuses are all 30A. I'm assuming I should
mention this to the owner and mention that he should get the correct sized
fuses in?

snip

You are probably not in a position to dictate to the
owner what he should do about all these problems. But at the
very least present him with some kind of statement of what was
found, for your own benefit if nothing else.

Jim

What do you think he meant by "I should mention this to the owner?"

Anyone have the thought that one of the fuses may have been the "main"
and the other fuse the "circuit"?


JK

Mains are not screw in. They are pull out type.

In article , Jeff Wisnia
wrote:

Charles wrote:

"Charles Bishop" wrote in message

...

While working in an older unit, I was helping to track down which fuse
controlled which circuit. The fuses were in a closet, in two separate fuse
boxes. These were the screw in/screw out fuses.

There were several porcelein fuse holders and each contained 2-4 fuses. I
unscrewed one fuse and noticed that the ceiling light in the bedroom went
out. However, when I unscrewed the other fuse in the porcelein fuse holder
(there were two) the same light went out. The same thing happened for the
light in the closet.


Why would two fuses control the same light?


The fuses are wired in series. Strange!

Maybe some know-nothing who wired the place put fuses in BOTH the hot
and neutral leads? That'd put them in series, but without a common
connection between them.

Someone with a voltmeter and a little knowledge could sort things out
pretty quickly.

I have both (heh), what should I do to test this hypothesis?

[snip]

--
charles

In article , "RBM" rbm2(remove
wrote:



"Terry" wrote in message
.. .
On 26 Apr 2007 17:05:32 -0700, Big_Jake
wrote:

On Apr 26, 7:04 pm, Terry wrote:
On Thu, 26 Apr 2007 16:30:18 -0400, Speedy Jim wrote:

snip



Oh, also, the wiring looks to be 12 or 14 ga (cloth covered, older
wire so
it's hard to tell), and the fuses are all 30A. I'm assuming I should
mention this to the owner and mention that he should get the correct
sized
fuses in?

[snip]

Anyone have the thought that one of the fuses may have been the "main"
and the other fuse the "circuit"?


JK

Mains are not screw in. They are pull out type.

Not necessarily, if the service was only 30 amp, it was common to have plug
fuses



I have the dwg I made on site in front of me now. I'll see what I can do
with ASCII art - 0 indicates a screw in fuse, X and empty space in the
fuse block, and the numbers are my reference numbers:


1 0 0 5

2 0 0 6



3 0 0 7

X 0 8

4 0



0 9

0 10


Not as good as I'd like, but it will do. Pairs 1, 2, then 3, 4, and 5, 6,
then 7, 8 and finally 9, 10 are in their own, separate, fuse block. All
but 9, 10 are porcelein blocks with space for two or 3 fuses. The one with
three (3, 4 pair) only has two in it. 9, 10 has a metal box, but still
with screw in fuses. I know that 1, 2 and 5, 6 both turn off separate
ceiling lights, but each one of the pairs turns off the same light. It
does sound as if the neutral is fused. I don't have any notes on whether
the other pairs behave similarily, but could check. It's a small 1 bedroom
unit in an older building in San Francisco, CA.

--
charles