FAS2050 + DS14MK4 shelves - grounding straps?

[strattonfinance]

Hi all,

We're in the middle of adding two DS14MK4 shelves to our FAS2050C. One of the steps in the installation instructions reads:

"7) Connect the grounding strap connecting the disk shelf to the other disk shelves or your storage system."

Three things we're confused about here, and can't seem to find answers for in the documentation:

1) The location to attach the grounding strap to the DS14MK4's is obvious, but we can't figure out where to attach it to the FAS2050. Any idea where it attaches?

2) There are two locations on each DS14MK4 to attach a grounding strap - immediately to the left and right of the ESH4 modules. Do we need to attach grounding straps to only one of these two locations per shelf (so one strap connecting each shelf / filer), or do we need to attach both?

3) Just confirming, we don't need to create a loop with the grounding straps, or attach them to anything except the shelves and the filer (no connection to the rack itself, or to any external earth / ground)? So it's just Shelf1 <-strap-> Shelf2 <-strap-> Filer?

Thanks, appreciate any info / advice.

Cheers,

Matt

[strattonfinance]

Bump... anyone?

[ekashpureff]

I'll take I stab in the dark at an answer !

: )

Use any of the screws on the 2050 chasis you can reach to attach the grounding straps.

Use two straps, for redundancy, if you have them.

You should already be grounded to rack with the mounting screws.

I did not go look at the hardware installation guides for these answers, but there probably is documentation on this.

I hope this response has been helpful to you.

At your service,

Eugene Kashpureff

NetAppU Instructor and Independent Consultant

(P.S. I appreciate points for helpful or correct answers.)

[strattonfinance]

Hi Eugene,

Thanks for the response 🙂

> Use any of the screws on the 2050 chasis you can reach to attach the grounding straps.

That's the problem... we can't find any screws / screw holes on the 2050 that look like they could be used as a mounting point for the grounding strap(s) :-S

> Use two straps, for redundancy, if you have them.

Will do - thanks.

> You should already be grounded to rack with the mounting screws.

Do you mean we should already be grounded to the rack simply by having mounted the filer / shelves in it? Not sure if that would be the case with our racks as they are covered in some sort of black powder-coating that doesn't look very conductive to me.

> I did not go look at the hardware installation guides for these answers, but there probably is documentation on this.

If there's documentation then I can't find it 😞

The DS14MK4 guide tells you to use the grounding straps but only cover the connection point(s) on the DS14MK4 itself, and there doesn't appear to be any information about grounding straps in the FAS2050 documentation.

Cheers,

Matt

[ekashpureff]

Matt -

You're very welcome.

Found the document:

http://now.netapp.com/NOW/public/knowledge/docs/hardware/filer/210-03951.pdf

"Note - You do not need to ground your system"

Rack screws will generaly ground on the threads when they have paint or coatings on them.

I hope this response has been helpful to you.

At your service,

Eugene Kashpureff
NetAppU Instructor and Independent Consultant
(P.S. I appreciate points for helpful or correct answers.)

[strattonfinance]

> Found the document:

>

> http://now.netapp.com/NOW/public/knowledge/docs/hardware/filer/210-03951.pdf

>

> "Note - You do not need to ground your system"

Thanks.

I guess that clears up grounding (or lack thereof) of the FAS2050 to the rack, but sounds pretty ambiguous with regards to the need to ground the shelves to the FAS2050. Would you agree? Or do you think "You do not need to ground your system" means that grounding the shelves to the FAS2050 is also not required?

[ekashpureff]

I agree, wholeheartedly !

I've been a big fan of proper grounding for a long time. I tell stories on the first day of DOTF class when I teach - the second slide in the class has bullet points on 'Electrical Safety' and 'ESD Procedures'.

( I'm pretty sure I discharged static on a Sun E6000 dual proc board once back at Mail.com, and blew it. Had the server room guys buy a case of ground wrist straps and install them on every rack ASAP! )

I have memories from long ago of ground loop interference in power supplies (c 1982).

: )

Given that the communication to the shelves is fibre, there shouldn't be differential ground problems with IO to the chasis, but a good earth ground on any chasis has always been a good idea.

Take the ohm meter 'round and check for chasis ground resistance ?

My two cents, and the documentation referenced.

I hope this response has been helpful to you.

At your service,

Eugene Kashpureff
NetAppU Instructor and Independent Consultant
(P.S. I appreciate points for helpful or correct answers.)