Junos
Junos

Removing the Extended Cable Manager Top Hat

‎07-09-2019 01:17 AM

Hi all,

 

Wrong forum, but I couldn't find a category where my question fits in.

So here goes.

 
Near the end of last year we bought the CHAS-BP-MX960-ECM-S chassis.
We came to believe that this chassis has a part at the top, specifically called the Extended Cable Manager Top Hat (ECMTH) which would either appear to consist out of two separate parts or just one entire part shoved on top of the line cards.
Since we don’t use the Extended Cable Manager that is placed in front of the ECMTH, we can save 5RU.
 
I opened a Service Request at JTAC (MyJuniper), and by the ECMTH instructions in below link, we believe that the ECMTH can be removed, leaving the Regular Top Hat (RTH) and install that back in.
 
 
Are the top parts on Figure 17, page 20 and Figure 18, page 21 different Top Hats or are the gray and blue parts separate from each other?
Would I be able to reverse the process shown in the PDF and pull off the blue part from the gray part and just reinsert the gray part? I would then only need to buy a small Rear Air Exhaust Gate instead of the Regular Top Hat.
 
Also, the PDF states that the router needs to be turned off for this procedure. But I firmly believe that that is not necessary. When we initially installed the chassis, the ribbon cable was'nt even connected properly resulting in the craft Interface not displaying any LEDs to burn.
 
Can anyone confirm?
 
Beeelzebub

 
3 REPLIES 3
Junos

Re: Removing the Extended Cable Manager Top Hat

‎07-09-2019 03:28 AM

Been a while since I have seen one of these assembled, but my recollection from reviewing the linked document is we do change the physical electrical connection for both the fan tray and the craft interface on the box during the process.  You might get away. without damage on the fan tray but I would not want to risk live connection on the craft interface module.

 

Steve Puluka BSEET - Juniper Ambassador
IP Architect - DQE Communications Pittsburgh, PA (Metro Ethernet & ISP)
http://puluka.com/home
Junos

Re: Removing the Extended Cable Manager Top Hat

[ Edited ]
‎07-09-2019 04:18 AM

Hey spuluka,

 

So you would say that both the Regular Top Hat displayed on Figure 16, page 19 has different electrical connections for both the fan tray and the craft interface as opposed to Figure 18, page 21?

 

Looking more closely to both pictures, the holes on the sides of the gray part have holes on different places. 

So it seems that I would need to buy the Original Top Hat, displayed on Figure 16 page 19.

 

I was hoping on removing the top part and only use the bottom part of the Top Hat, displayed on Figure 18, page 21 and therefore only having to buy the small Rear Air Exhaust Gate, displayed on Figure 12, page 14.

 

I might better check this with an offline MX960 chassis at one of my (re)sellers.

It haven't been able to confirm this by only checking documentation or JTAC.

 

Beeelze

Junos

Re: Removing the Extended Cable Manager Top Hat

‎07-10-2019 03:26 AM

I've only ever deployed the extended top hat so I am not sure if they are different or not.

 

My main point is there are electrical connections made during the installation that power the fans and craft interface.  So that is likely why power must be off during the process.  These are likely not hot plugable options.

 

Steve Puluka BSEET - Juniper Ambassador
IP Architect - DQE Communications Pittsburgh, PA (Metro Ethernet & ISP)
http://puluka.com/home