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RE: Burned Connectors in PCs
Pierre,
Here
are some suggestions:
1.
Look into the power delivery of the backplane. Check with the vendor and
ask him how much power his backplane can deliver. Power planes should be 2
oz. copper to achieve good current delivery. It may be that there is too much of
a drop in voltage across the backplane. You should measure the voltage
near the connector on the PS board and just beyond the connector on your
function cards to see how much voltage drop you may be encountering.
2.
Check with the vendor of the connector on the backplane and
confirm:
- the recepticle spring pins can handle the
proper amount of current
- The connector plastic has a high enough temperature
rating. I don't remember what the specs are, but there are two types of
connector body plastics that are typically used: one has a higher temp rating
somewhere around 125C before melting occurs.
3. If
position in the cage is not an issue, locate your highest current drawing
board closest to the PS.
4.
Count up all of the pins you are using to deliver 5V. The spec says 1 amp
per pin. If you are exceeding the total current that can be
delivered to a card slot, you are in danger of creating a potential
hazard. You should also check with the PS vendor and make sure he has a
built-in short circuit shut down mode. Otherwise, should a fire start, the
PS will be feeding the fire.
5. If
the power supply connector is different from the function card connectors, make
sure that the pins that are used can carry the maximum current specified by the
power supply designer.
6.
Have a conversation with the vendors of the backplane and power supply and ask
some questions of them.
Thanks,
Jim
Fisher
We have a rackmount PC with a 400 Watt
power supply. The power consumption of all our cards is quite high,
about 284 Watts, still less then 75% of the rating though. The power
supply is rated for
30-50A for the +5V
20-11A for the
+12V
Shared
between the 2
We are drawing 36A of +5 and 8A on the +12
The problem
is that, after time (6 months - 1 year), the units will fail and we noticed
that the connectors which mate with the backplane are actually fused(melted)
to the backplane. In line with the +5 V wires (red wires), the connector
is actually black and in many cases the connector is arc welded to the
backplane.
Ideas.
... Pierre