3 blown Power supply's in 6 months.

An old horse story!

I was doing T.V. repair in the 60's. There was a new high rise in Fort Lee,
NJ. One of our technicians was up on the 9th floor working on a woman's
console T.V. (friggin HUGE). He was squatting down behind the set - the
power was off. He accidentally touched the 2nd anode on the CRT. His legs
convulsed and sprung him backward, through the open sliding balcony doors
and over the rail to his death!

He was my friend.

--
Regards,

Richard Urban

aka Crusty (-: Old B@stard :-)

If you knew as much as you think you know,
You would realize that you don't know what you thought you knew!


Vanguard wrote in message ...
"Leythos" wrote in message
...

Most computer PSU's use CAPS on the DC side and they don't have more
than 20+ VDC on most of them, the caps will also discharge in a short
amount of time due to the way a PSU is designed.


It is not so much of getting a small shock, if any. It is usually more
the case of causing physical damage to yourself due to the involuntary
quick withdraw of your hand. Getting a shock often doesn't do much harm
when working on electronics, but you've spent 5 minutes winding your
fingers, hand, and arm in amongst all the cords and components, some of
which have barbs or sharp edges. When you get shocked, you withdraw in a
straight line and drag your skin across all those jaggies. The shock
didn't hurt you. You hurt your because of your reaction the the shock.
The bzzzt or buzz might not hurt, but your hand or arm might look like you
had a fight with a feral cat.

I'd give the PSU about 10 minutes to discharge, and that is WITH the power
cord connected to the computer and to the outlet. If the OP is sucking
out an excessive amount of current, there is also a good chance that some
parts are hot inside.

--
__________________________________________________ __________
** Post your replies to the newsgroup - Share with others **
For e-mail Reply: remove "DELETE", add "~VN56~" to Subject.
__________________________________________________ __________

I would have wanted to have the motor draw too much current, and run for
another minute. That could be the difference between a massive explosion and
loss of human life OR the opportunity for the plant personnel to vacate!

--
Regards,

Richard Urban

aka Crusty (-: Old B@stard :-)

If you knew as much as you think you know,
You would realize that you don't know what you thought you knew!


"Leythos" wrote in message
...
In article ,
says...
Hell. There were times in my past career when I would not even fuse a
10HP
440/460V motor. I would rather have it burn up than have a fuse blow at
an
inopportune time. Example: an emergency ventilator in an explosive
atmosphere. When the LFL (lower flammability limit) reached 7.5% that
motor
came on and ran until the environment was again safe or the motor
destroyed
itself because of "whatever"!

That's not right, if the motor is drawing too much current, there is a
reason, and continued running will generate excessive heat, which is
worse on a vent for an explosive environment. Heck, even the heaters
could kick-out a motor before the fuses did in some cases - where the
fuses were sized wrong.

--
--

remove 999 in order to email me

I would have wanted to have the motor draw too much current, and run for
another minute. That could be the difference between a massive explosion and
loss of human life OR the opportunity for the plant personnel to vacate!

--
Regards,

Richard Urban

aka Crusty (-: Old B@stard :-)

If you knew as much as you think you know,
You would realize that you don't know what you thought you knew!


"Leythos" wrote in message
...
In article ,
says...
Hell. There were times in my past career when I would not even fuse a
10HP
440/460V motor. I would rather have it burn up than have a fuse blow at
an
inopportune time. Example: an emergency ventilator in an explosive
atmosphere. When the LFL (lower flammability limit) reached 7.5% that
motor
came on and ran until the environment was again safe or the motor
destroyed
itself because of "whatever"!

That's not right, if the motor is drawing too much current, there is a
reason, and continued running will generate excessive heat, which is
worse on a vent for an explosive environment. Heck, even the heaters
could kick-out a motor before the fuses did in some cases - where the
fuses were sized wrong.

--
--

remove 999 in order to email me

Another human life saved.. wow..

--
Mike Hall
MVP - Windows Shell/User
http://dts-l.org/goodpost.htm





"Leythos" wrote in message
...
In article , Vanguard says...
"J-Dee" wrote in message
...
im from UK and every power cable has to have a fuse in UK so suppose
it
depends where your from. if you use fuses it could well be a problem.


If that is true then the fuse needs to be the slow-blow type. The
sudden burst of amps surging through a normal fuse could easily blow it
when the computer is powered on. The slow-blow fuse will prevent it
from opening for a short one-time surge. However, if the fuse in the
power cord blew then the OP would be asking why he has to keep replacing
power cords or the fuses in them. He is saying that he is replacing
PSUs. Even if he replaced the PSU, it wouldn't work until he replaced
the power cord fuse, so he would've still mentioned having to replace
fuses. Doesn't sound like it is a fuse problem.

Actually the OP stated, later, that he found a fuse blown inside the PSU
once he opened it.

--
--

remove 999 in order to email me

Another human life saved.. wow..

--
Mike Hall
MVP - Windows Shell/User
http://dts-l.org/goodpost.htm





"Leythos" wrote in message
...
In article , Vanguard says...
"J-Dee" wrote in message
...
im from UK and every power cable has to have a fuse in UK so suppose
it
depends where your from. if you use fuses it could well be a problem.


If that is true then the fuse needs to be the slow-blow type. The
sudden burst of amps surging through a normal fuse could easily blow it
when the computer is powered on. The slow-blow fuse will prevent it
from opening for a short one-time surge. However, if the fuse in the
power cord blew then the OP would be asking why he has to keep replacing
power cords or the fuses in them. He is saying that he is replacing
PSUs. Even if he replaced the PSU, it wouldn't work until he replaced
the power cord fuse, so he would've still mentioned having to replace
fuses. Doesn't sound like it is a fuse problem.

Actually the OP stated, later, that he found a fuse blown inside the PSU
once he opened it.

--
--

remove 999 in order to email me

In article ,
says...
An old horse story!

I was doing T.V. repair in the 60's. There was a new high rise in Fort Lee,
NJ. One of our technicians was up on the 9th floor working on a woman's
console T.V. (friggin HUGE). He was squatting down behind the set - the
power was off. He accidentally touched the 2nd anode on the CRT. His legs
convulsed and sprung him backward, through the open sliding balcony doors
and over the rail to his death!

He was my friend.

That's terrible, worst incident of appliance shocking I've ever read.
Sorry for your loss.

When I worked on 14kv lines, I remove all metal from my person, at least
as much as possible.

We had a couple incidents where people were racking in switch-gear and
crossed the stabs and made a real big mess, but I wasn't around then. We
even had a contractor vacuuming a 14kv unit after they had drilled holes
in the panels/sides - the dust arced against the bus bars... He had
copper colored safety glasses and burns on his arms/face.

I've also seen contractors cut conduits that were suppose to be safed,
only to have the 440 still be hot.

One time, when I was new to all of this, I was following an old timer on
a motor replacement on an automated system - it was only about 5HP, but
he had turned the machine to STOP (not power off) and told me to just go
ahead and wire the pecker-head. Being young, stupid, and new, I grabbed
the three lines, they brushed up against the stair frame and made one
heck of a bang. I never followed anyone again without making the system
safe (electrical/mechanical) again.


--
--

remove 999 in order to email me

In article ,
says...
An old horse story!

I was doing T.V. repair in the 60's. There was a new high rise in Fort Lee,
NJ. One of our technicians was up on the 9th floor working on a woman's
console T.V. (friggin HUGE). He was squatting down behind the set - the
power was off. He accidentally touched the 2nd anode on the CRT. His legs
convulsed and sprung him backward, through the open sliding balcony doors
and over the rail to his death!

He was my friend.

That's terrible, worst incident of appliance shocking I've ever read.
Sorry for your loss.

When I worked on 14kv lines, I remove all metal from my person, at least
as much as possible.

We had a couple incidents where people were racking in switch-gear and
crossed the stabs and made a real big mess, but I wasn't around then. We
even had a contractor vacuuming a 14kv unit after they had drilled holes
in the panels/sides - the dust arced against the bus bars... He had
copper colored safety glasses and burns on his arms/face.

I've also seen contractors cut conduits that were suppose to be safed,
only to have the 440 still be hot.

One time, when I was new to all of this, I was following an old timer on
a motor replacement on an automated system - it was only about 5HP, but
he had turned the machine to STOP (not power off) and told me to just go
ahead and wire the pecker-head. Being young, stupid, and new, I grabbed
the three lines, they brushed up against the stair frame and made one
heck of a bang. I never followed anyone again without making the system
safe (electrical/mechanical) again.


--
--

remove 999 in order to email me

In article ,
says...
I would have wanted to have the motor draw too much current, and run for
another minute. That could be the difference between a massive explosion and
loss of human life OR the opportunity for the plant personnel to vacate!

I would have been afraid that the load could be caused by a shaft
bearing or some other physical condition that could lead to
sparks/excessive heat.

We used double exhaust systems in our grain systems, same in the cement
systems, in case one purge system didn't work.

--
--

remove 999 in order to email me

In article ,
says...
I would have wanted to have the motor draw too much current, and run for
another minute. That could be the difference between a massive explosion and
loss of human life OR the opportunity for the plant personnel to vacate!

I would have been afraid that the load could be caused by a shaft
bearing or some other physical condition that could lead to
sparks/excessive heat.

We used double exhaust systems in our grain systems, same in the cement
systems, in case one purge system didn't work.

--
--

remove 999 in order to email me

In article ,
says...
Another human life saved.. wow..

Mike, just in case you misunderstood my reply, I was also agreeing with
you. I've not seen much out of Tom that makes sense.

--
--

remove 999 in order to email me

In article ,
says...
Another human life saved.. wow..

Mike, just in case you misunderstood my reply, I was also agreeing with
you. I've not seen much out of Tom that makes sense.

--
--

remove 999 in order to email me

When I was in Electronic school, courtesy of the Navy, we were in our 3
phase section of training. We each had out own work module and fuse box.
After coming back from coffee break one day a young fella a few seats down
picks up the three phase leads and says "I wonder if these are hot?". He
then touched two of the phases together. He woke up 3 days later in
intensive care.

--
Regards,

Richard Urban

aka Crusty (-: Old B@stard :-)

If you knew as much as you think you know,
You would realize that you don't know what you thought you knew!


"Leythos" wrote in message
...
In article ,
says...
An old horse story!

I was doing T.V. repair in the 60's. There was a new high rise in Fort
Lee,
NJ. One of our technicians was up on the 9th floor working on a woman's
console T.V. (friggin HUGE). He was squatting down behind the set - the
power was off. He accidentally touched the 2nd anode on the CRT. His legs
convulsed and sprung him backward, through the open sliding balcony doors
and over the rail to his death!

He was my friend.

That's terrible, worst incident of appliance shocking I've ever read.
Sorry for your loss.

When I worked on 14kv lines, I remove all metal from my person, at least
as much as possible.

We had a couple incidents where people were racking in switch-gear and
crossed the stabs and made a real big mess, but I wasn't around then. We
even had a contractor vacuuming a 14kv unit after they had drilled holes
in the panels/sides - the dust arced against the bus bars... He had
copper colored safety glasses and burns on his arms/face.

I've also seen contractors cut conduits that were suppose to be safed,
only to have the 440 still be hot.

One time, when I was new to all of this, I was following an old timer on
a motor replacement on an automated system - it was only about 5HP, but
he had turned the machine to STOP (not power off) and told me to just go
ahead and wire the pecker-head. Being young, stupid, and new, I grabbed
the three lines, they brushed up against the stair frame and made one
heck of a bang. I never followed anyone again without making the system
safe (electrical/mechanical) again.


--
--

remove 999 in order to email me

When I was in Electronic school, courtesy of the Navy, we were in our 3
phase section of training. We each had out own work module and fuse box.
After coming back from coffee break one day a young fella a few seats down
picks up the three phase leads and says "I wonder if these are hot?". He
then touched two of the phases together. He woke up 3 days later in
intensive care.

--
Regards,

Richard Urban

aka Crusty (-: Old B@stard :-)

If you knew as much as you think you know,
You would realize that you don't know what you thought you knew!


"Leythos" wrote in message
...
In article ,
says...
An old horse story!

I was doing T.V. repair in the 60's. There was a new high rise in Fort
Lee,
NJ. One of our technicians was up on the 9th floor working on a woman's
console T.V. (friggin HUGE). He was squatting down behind the set - the
power was off. He accidentally touched the 2nd anode on the CRT. His legs
convulsed and sprung him backward, through the open sliding balcony doors
and over the rail to his death!

He was my friend.

That's terrible, worst incident of appliance shocking I've ever read.
Sorry for your loss.

When I worked on 14kv lines, I remove all metal from my person, at least
as much as possible.

We had a couple incidents where people were racking in switch-gear and
crossed the stabs and made a real big mess, but I wasn't around then. We
even had a contractor vacuuming a 14kv unit after they had drilled holes
in the panels/sides - the dust arced against the bus bars... He had
copper colored safety glasses and burns on his arms/face.

I've also seen contractors cut conduits that were suppose to be safed,
only to have the 440 still be hot.

One time, when I was new to all of this, I was following an old timer on
a motor replacement on an automated system - it was only about 5HP, but
he had turned the machine to STOP (not power off) and told me to just go
ahead and wire the pecker-head. Being young, stupid, and new, I grabbed
the three lines, they brushed up against the stair frame and made one
heck of a bang. I never followed anyone again without making the system
safe (electrical/mechanical) again.


--
--

remove 999 in order to email me

In article ,
says...
When I was in Electronic school, courtesy of the Navy, we were in our 3
phase section of training. We each had out own work module and fuse box.
After coming back from coffee break one day a young fella a few seats down
picks up the three phase leads and says "I wonder if these are hot?". He
then touched two of the phases together. He woke up 3 days later in
intensive care.

I was in AT (Avation Electronics Technician) training in Memphis around
84, I saw things like that once in a while during my 3 months there

--
--

remove 999 in order to email me

In article ,
says...
When I was in Electronic school, courtesy of the Navy, we were in our 3
phase section of training. We each had out own work module and fuse box.
After coming back from coffee break one day a young fella a few seats down
picks up the three phase leads and says "I wonder if these are hot?". He
then touched two of the phases together. He woke up 3 days later in
intensive care.

I was in AT (Avation Electronics Technician) training in Memphis around
84, I saw things like that once in a while during my 3 months there

--
--

remove 999 in order to email me