Electrical Engineering - Those darn fuses

Author

Those darn fuses

Gerald Newton

2007-01-25, 3:25 am

My bother-in-law called and said his furnace was off again after he was
billed $240 by the local repair shop. I called the repair shop but they
wouldn't come again until the bill was paid. I said that the bill shouldn't
be paid until the furnace works. So I took my tools and meter to town and
began trouble shooting.
A relay in the fire eye control for the oil burner chattered every time we
tried to start the burner. Well, this was easy, I replaced the control.
Turned it on and it chattered again. I checked the voltage at the switch,
it read 108 volts. I checked the voltage at the panel - 108 volts from A to
neutral and 120 volts from B to neutral, and 0 volts from A to B. What the
hell, I thought. Something is weird here. The burner breaker was on A bus
so I changed it to B bus and the burner took off. I next went to the
service. And guess what I found? A fifty year old service panel with two
60 ampere fuses and the one on A phase was open.
Apparently, the hot water heater that was on 240 volts was allowing B phase
to back feed into the neutral through A phase loads setting up a voltage
divider. I asked my brother-in-law if he had any hot water and he said not
since the furnace went off. Hey, this is what I should have asked before I
spent $80 for a new controller. I asked if some of the lights had been
dimming at times. Oh yes, he said. Again, I should have asked that too.
But mainly, I should have looked at the service. Who would think a house
would have fuses this day and age?
As for the service repair shop - well I asked my brother in law if the hot
water went off after the repairman was there and he said yes, and that his
brother who had been staying in the basement was using some electric heaters
to get warm. Darn residential work, it will get you every time.

Ben Miller

2007-01-25, 5:25 pm

"Gerald Newton" <GeraldCNewton@hotmail.com> wrote in message
news:V7Cdna6NhfOK2yXYnZ2dnUVZ_s2vnZ2d@giganews.com...
> But mainly, I should have looked at the service. Who would think a house
> would have fuses this day and age?

A lot of old homes and apartment buildings in the Chicago area still have
the old 4-circuit+range+main fuse boxes (one per apartment). There is always
a pile of 20A fuses nearby.

Ben Miller

--
Benjamin D. Miller, PE
B. MILLER ENGINEERING
www.bmillerengineering.com

Mike Lamond

2007-01-26, 3:25 am

"Ben Miller" <benmiller@worldnet.att.net> wrote in message
news:eJidnezaF8nMryTYnZ2dnUVZ_smonZ2d@comcast.com...
> "Gerald Newton" <GeraldCNewton@hotmail.com> wrote in message
> news:V7Cdna6NhfOK2yXYnZ2dnUVZ_s2vnZ2d@giganews.com...
>
> A lot of old homes and apartment buildings in the Chicago area still have
> the old 4-circuit+range+main fuse boxes (one per apartment). There is
> always a pile of 20A fuses nearby.
>
> Ben Miller
>
> --
> Benjamin D. Miller, PE
> B. MILLER ENGINEERING
> www.bmillerengineering.com
That's what the apartments in my building have, vintage 1960. All apartments
except for the basement apartment also have an extra two-fuse box below
that to provide an extra 120 volt circuit for the air conditioner. It looks
like
the original work, too, instead of a later addition. The house panel,
meanwhile,
is a 12-space circuit breaker panel.

There was also a 100-amp 8-circuit + range + main version of the fuse box.
I've seen just two: one in a 1957 house and the other in a tiny booster pump
station serving the last dozen houses at the highest point in a municipal
water
system.

Mike

John Smyth

2007-01-26, 9:25 am

"Ben Miller" <benmiller@worldnet.att.net> wrote in message
news:eJidnezaF8nMryTYnZ2dnUVZ_smonZ2d@comcast.com...
> "Gerald Newton" <GeraldCNewton@hotmail.com> wrote in message
> news:V7Cdna6NhfOK2yXYnZ2dnUVZ_s2vnZ2d@giganews.com...
house[color=darkred]
>
> A lot of old homes and apartment buildings in the Chicago area still have
> the old 4-circuit+range+main fuse boxes (one per apartment). There is
always
> a pile of 20A fuses nearby.
>

What, you've got actual fuses?
Most houses in Australia until about 15 years ago had fuse wire that you had
to install into the fuse-wire holder.
Later upgrades now use circuit breakers.
But stoves/ovens still have cartridge fuses assembled inside them.

John Smyth
Sydney Australia

> Ben Miller
>
> --
> Benjamin D. Miller, PE
> B. MILLER ENGINEERING
> www.bmillerengineering.com
>
>

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