Nortel Passport 15000 Hardware Installation And Maintenance page 729

If the sparing panel is mounted in a NEBS 2000 frame (NTRU04), the
sparing panel is grounded through the mounting ears into the frame
uprights.
4 Note the orientation of the sparing panel, for example, do the connectors
face into the mounting apparatus or out of it.
5 Note where the sparing panel fasteners are located on the mounting
apparatus.
6 Unfasten the sparing panel, progressing from bottom to top. Put the
fasteners aside for re-use.
When you are removing a 12-port sparing panel NTQS31, as the top 2
thread-forming 10-mm (3/8-in.) hex-head screws are unfastened, have
your helper hold the sparing panel. The helper must also wear a properly
grounded anti-static wrist strap.
When you are removing a 19-inch wide sparing panel, and a ground cable
shares one of the panel mounting fasteners (usually 8-mm or 5/16-in. EIA
screws), loosely fasten the cable back in the same hole after the panel is
removed.
7 Put the panel aside for packing later.
Passport 15000, 20000 Hardware Installation, Maintenance, and Upgrade
Chapter 17 Hardware procedures 729
5.2S2