19 Dec
2002
19 Dec
'02
1:38 p.m.
Hi
I've just seen the third surge protector blow
up and this time, it almost started a real fire.
I've had two of these go up in smoke that were
in metal strips. These generally make a lot of
smoke but I think the metal spreads the heat enough
that the fire danger is small. Now, most of the
newer ones are made from plastic. The last one
that just burned, started a small fire on the back
side of a chest of drawers. Luckily, the chest
didn't stay lit. It did charcoalize one of the feet.
While these things come with a 15 amp breaker,
the MOV's fail and draw something less then what
is required to blow the breaker.
I wonder if any of the fire prevention groups are
looking into these time bombs?
Dwight
19 Dec
19 Dec
1:58 p.m.
On Thu, 19 Dec 2002, Dwight K. Elvey wrote:
I've just seen the third surge protector blow up
and this time, it
almost started a real fire. I've had two of these go up in smoke that
were in metal strips. These generally make a lot of smoke but I think
the metal spreads the heat enough that the fire danger is small. Now,
most of the newer ones are made from plastic. The last one that just
burned, started a small fire on the back side of a chest of drawers.
Luckily, the chest didn't stay lit. It did charcoalize one of the feet.
While these things come with a 15 amp breaker, the MOV's fail and draw
something less then what is required to blow the breaker.
I wonder if any of the fire prevention groups are looking into these
time bombs?
There is supposed to be a small fuse installed in-line with the group of
MOVs, but some companies omit it and install a jumper wire in it's place.
Often the fuse isn't a glass fuse, but just a small bit of fuse wire
soldered directly to the pc board.
The 15A breaker is just for equipment connected to the strip.
-Toth
7:50 p.m.
I've just seen the third surge protector blow
up and this time, it almost started a real fire.
I wonder if any of the fire prevention groups are
looking into these time bombs?
Are you buying units that are UL approved?
When I blow up power strips so far all I get are sparks and a very small
puff of smoke.
20 Dec
20 Dec
12:26 a.m.
----- Original Message -----
From: "Mike Ford" <mikeford(a)socal.rr.com
To: <cctalk(a)classiccmp.org
Sent: Friday, December 20, 2002 1:54 AM
Subject: Re: Surge protectors or fire hazard
I've heard, but never verified, that some units that appear to be Listed
merely use a Listed cordset.
Bob
I've just seen the third surge protector
blow
up and this time, it almost started a real fire.
I wonder if any of the fire prevention groups
are
looking into these time bombs?
Are you buying units that are UL approved?
When I blow up power strips so far all I get are sparks and a very small
puff of smoke.
My folks had one that quit working. When I opened it up, the internal
connections were made with 18ga wire!
7:14 a.m.
New subject: UL listing (was Re: Surge protectors or fire hazard)
Are you buying units that are UL approved?
Minor nit: UL doesn't "approve" anything. Items that pass their
tests are "listed".
I assume this is because if they were to "approve" something they might
incur legal liability.
4:10 a.m.
The MOVs used in these things fail by shorting. When they short, they put a short
directly across the AC line. Building one of these things without fuses or circuit
breakers in BOTH legs is just looking for trouble. You should report these incidents to
your state and local fire marshall, as many consumer agencies as you can find and the
store that sold them to you.
You need a protective device (fuse or circuit breaker but fuse prefered) in BOTH AC
legs since the power surge can be differeential (across the AC line) or common mode (where
the voltage increasses in both AC lines). Don't put a protective device in the ground
line!
FWIW I pick up old power supplies and surge protectors and save the MOVs out of them.
Then anytime that I work on a computer or other electrical device I add a MOV across the
AC line and a MOV between each AC line and ground. I also add fuses in each AC line ahead
of the MOVs. Even with these changes I still use surge protectors whenever possible, call
it double insurance. I live in the lightning capital of the world (central Florida) and
I've yet to lose a computer or TV to lighting despites numerous close hits. I've
lost plenty of MOVs and surge protectors though.
Joe
At 04:39 PM 12/19/02 -0800, you wrote:
Hi
I've just seen the third surge protector blow
up and this time, it almost started a real fire.
I've had two of these go up in smoke that were
in metal strips. These generally make a lot of
smoke but I think the metal spreads the heat enough
that the fire danger is small. Now, most of the
newer ones are made from plastic. The last one
that just burned, started a small fire on the back
side of a chest of drawers. Luckily, the chest
didn't stay lit. It did charcoalize one of the feet.
While these things come with a 15 amp breaker,
the MOV's fail and draw something less then what
is required to blow the breaker.
I wonder if any of the fire prevention groups are
looking into these time bombs?
Dwight
7886
days inactive
7887
days old
6 comments
6 participants
participants (6)
-
dwightk.elvey＠amd.com -
eric＠brouhaha.com -
mikeford＠socal.rr.com -
rigdonj＠cfl.rr.com -
rschaefe＠gcfn.org -
tothwolf＠concentric.net