The DIY harness maker strikes again

[spackard]

About 20 years ago availability of wire ties shot up.
The younger sysadmins make liberal use of them in server racks.

Before that, the only time I saw wiring harnesses was in autos, planes,
and in various aerospace assemblies. The quality of those was high to
exceptional. The aerospace ones always have anchors woven into them;
you're supposed to take a proper screw and nut fastener and anchor
the harness to the chassis, and the anchors take the weight of the harness
off the ends.

Sysadmins don't take notice of this; they grab a handful of like cables and
tie them together "to look pretty". That starts a time-bomb ticking.
About 6 months later, something will pull out because of all the weight
it has to now support. This morning it was a power cord for a network switch.
The switch is mounted on a wall (network ports pointing up to collect dust)
in a lab, and when the technicians
mounted it to the wall about 6 months ago they wrapped together all the power
and network wires together. Okay, this time it wasn't a sysadmin. But still.

 

[pandus13]

oh come on...

That was to mask a need for later calls... for problem hard to replicate....

Now instead of dust imagine dust + (machine oil + coolant) mist.
Yummylicious.... also makes network cable plastic ends brittle after about 2.5-3 years....
AKA Crummylicious...

My good example is guys tying all the cables on a system where monitor + computer cart is supposed to move...No slack given... Yup, couple of hard power-offs on an expensive piece of machinery....

 

[Kira]

So what you're recommending is bundling, say, power supply lines together then segregating them from signal lines or bundles.

Also, you're underscoring the use of proper strain reliefs and anti-chafing methods? Yes?

I've learned that keeping like wires together also speeds trouble shooting. Thanks for the post.

 

[andyd]

Originally Posted By: Kira
So what you're recommending is bundling, say, power supply lines together then segregating them from signal lines or bundles.

Also, you're underscoring the use of proper strain reliefs and anti-chafing methods? Yes?

I've learned that keeping like wires together also speeds trouble shooting. Thanks for the post.
Power and signal are s'posed to be separately. Cable ties? use 9 ply waxed lacing cord for a much neater job.

 

[PimTac]

Details matter. In my prior place of work all the computers were on the floor under the counters. One day the housekeeping person moved one of the boxes to vacuum around and the whole system went down. Nobody figured it out for hours.

It probably happens every day at a workplace near you.

 

[Linctex]

Originally Posted By: andyd
Power and signal are s'posed to be separately.


All modern computer cords are foil lined/shielded against RF

 

[JustinH]

All the server/network gear racks I have setup come with APC vertical cable management systems.

Its pretty simple to run all the cables through it and make it look perfect.

Same with all the power to tie into the PDU.

At home I just bundle everything together with velcro.

 

[CourierDriver]

 

[spackard]

Someone finally invented a snap-in jack for an IEC-320 C13.
Rather, a manufacturer spent the extra money to put one of these on the
back of their server equipment.
It's in a NetApp disk shelf. The other sysadmin didn't seat the cord properly.
He didn't snap it in.

I was troubleshooting another problem and saw a loss of power message in the log.
Travel a mile, then walk the aisle looking for yellow LEDs and found it.
He had sent a few emails, but couldn't repair it and left it.
The last time he had any reason to be back there was, yup, 6 months ago,
Thanksgiving.