I live in a 1960's condo in Souther California. Some of the circuit
breakers have been buzzing since I moved in a few months ago. One in
particular would lose power until it was manipulated into the right
position on the breaker box (some of the breakers are very loose). A
few days ago, the most problematic breaker stopped working, killed the
fridge, and I have not been able to get power back to this side of the
The breaker of interest is a double 20amp 2-pole Type Q Zinsco R38.
There does not to appear to be a main breaker that powers down
everything in this box. Am I running any great risk by taking this
breaker out while with the wires still hooked up to it (or even
disconnecting the wires with the breaker switched off)? I am willing
to face anything but death; I'm young and healthy, and I fix cars and
computers and do some home repair (just fyi). My idea is to replace
the breaker with another, less critical, breaker from the box just (i
don't need all of the wall receptacles to have power).
I will appreciate any thoughts on this issue.
There is probably a main disconnect for your panel at the metering
equipment, and it would certainly be the safe thing for you to do, to turn
it off. It's entirely possible that the buss in the panel,(the electrically
live metal parts) is damaged and this is why the breakers are not making
solid contact. You would probably be wise to have an experienced person look
at it, and replace it if necessary
Zinsco breakers are notorious for being bad and are not supported
by anyone and they are not rated by UL.
Parts and pieces tend to be expensive. There were some
replacement systems that removed the "guts" of the panel and
replaced the bus and breakers.
Electricians can work hot breakers, but everyone would prefer
killing the power. If you are not familiar with the work, get a
licensed electrician involved. Be aware, all electricians will
suggest replacing the system. Most will not have Zinsco breakers
nor have much interest in finding them.
Keep the whole world singing. . . .
It is relatively safe to work on a breaker with the breaker off.
I would switch off all breakers, remove the wires from the breakers
involved , swap out the breaker thats faulty and then reconnect the
The bus that feeds power to the breakers is not exposed with all
breaker positions filled.
However, HOWEVER, it is much safer to cut power to the box . There is
probably a disconnect on the main distribution and meter panel.
As others have suggested you might do better to have the box replaced.
You are only talking about an hours work if it is a straight box swap.
I am guessing if it is physically within the condo that it is probably
flush mounted meaning that there will be painting and patching work
needed after the box is swapped out. However, I am not stating that
it's still not a good idea. I don't have any knowldge of Zinsco other
than what I've heard in this thread, but if I've never heard of them
how good could they be?
A humming sound from breakers is pretty normal. A sizzling sound
indicates an arc. Having to move the breaker to get to work sounds like
a bad connection to the bus - arcing.
If you are moving the wires to another breaker you don't have to remove
the bad breaker, just move the wires. Wires from multiple breakers can
be pigtailed together and connected to a single breaker of the same amp
rating. If the circuit has 2 hot wires sharing a single neutral you have
to know how to do this safely. Kitchen and laundry cirucits shouldn't be
If you remove the breaker and leave it out you will have an open space
to the bus with the trim cover back on unless you have a filler plate -
not safe. If the breaker arced to the bus, that bus position is damaged
and a new breaker should not be installed there. On the otherhand, if
there is major damage to the breaker it should be removed. If the
breaker does not come out easily I would be real nervous about pulling a
Zinsco breaker without killing the panel.
As others have said there may well be a service disconnect outside. If
there is not protection ahead of the panel, concern about the panel
should increase. It would be a good idea to be thinking about replacing
the panel. As you have no doubt picked up from other posts, Zinsco has
Zinsco was bought by Sylvania long ago.
One source of information on Zinsco is:
I havn't looked at the Zinsco section, but I think the section on
aluminum is very good.
The power is AC - 60Hz. With current flow a 60Hz magnetic field is
produced which can cause small movement of parts within the breaker
causing a hum. The field can act directly on magnetic parts, or the
fields of 2 nonmagnetic parts conducting current can interact. You
wouldn't hear it at low current and it wouldn't be very loud with the
current likely drawn in a house panel. I have heard it on loaded 15 &
20A breakers. The sizzling sound from an arc isn't very loud either.
No humming or sizzling from my house panel even with the 240V electric range
on high. I just put on a stethoscope on every breaker in the house panel an
all I hear is the sound from the hot water heater pilot light transmitted
through the insulated stud wall and then through the electrical panel
cavity. What your hear must be a defective breaker/panel. Arching is pretty
bad and its an indication of meld down temperatures much like in welding.
Yes I do hear humming in electrical switchgears (2,000A or such) but that is
from the relays and respective CTs (control transformers).
I have located several breakers with arcing connections to the bus from
fairly faint sizzling sounds - damage to the bus was apparent when the
breaker was removed. I used a screwdriver as a stethescope to isolate
the noise to a specific breaker. In my experience hum is not real
uncommon in loaded breaker panels.
Thanks for all of the helpful advice. I did some looking around
outside of the building and I found the metering equipment with the
main power cutoff switches. The buzzing and sparking that I've
witnessed in the last month or so must be the arcing. My eyes have
been opened to the Zinsco problem.
Most of the wall receptacles in this place are worn out to the point
where they wont hold a plug. When I replaced one of the receptacles, I
couldn't find the green "ground wire" that the instructions were
telling me to connect - I guess they left that wire out when they did
the wiring here. From what I can tell, everything in this condo is D
grade or lower. My position here is sub-renting from a sub-leaser - I
have absolutely no connection to the person(s) that owns this condo,
which is pretty funny. What's even funnier is that out here, this condo
is probably worth 350k+.
On 20 Dec 2006 16:53:45 -0800, " firstname.lastname@example.org"
There have been problems with Zinsco's, I've been told, so I would
highly suggest you seek the professional advice of an electrician.
Should you need a panel replacment, something you should be prepared
for, get atleast three estimates, and references for work done.
tom @ www.FreeWorkAtHomeIdeas.com
On 22 Dec 2006 07:49:05 -0800, email@example.com wrote:
From what I heard about Zinsco's, the problem isn't the breakers, but
the panel's bus bars. So a new service panel could be the course of
action. Get a professional to evaluate the condition of the panel.
tom @ www.freecreditcheckguide.com
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