IBM 3745 130, Maintenance Information Procedures

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Safety
Ground Pin
Figure 0-6. Ground Pin on Mainline ac/dc Power Cable
c
Internal Grounding in the 3746-900 and Controller Expansion
On the 3746-900
Ÿ Check that electrical continuity is assured between the LCB housing and 3746-900 frame,
if LCBs are present. This operation must be performed before any network connection.
On the Controller Expansion
Ÿ Check that electrical continuity is assured between each machine installed in the controller
expansion (service processor, network node processor, modem, optical disk drive, and so
on) and the ground pin of the ac outlet distribution box (see Figure 0-7).
Ÿ Check that electrical continuity is assured between the ground pin of the ac outlet distrib-
ution box and the controller expansion mount frame.
Ground Pin
Figure 0-7. Ground Pin of the Controller Expansion ac Outlet Distribution Box
Ÿ Check that electrical continuity is assured between the LCB housing and the controller
expansion frame, if LCBs are present. This operation must be performed before any
network connection (see Figure 0-8 on page xxvi).
Note: All the previous measurements should indicate 0.1 ohm or less.
d
Grounding of Line Connection Boxes (LCBs) not Installed in the 3746-900 or Controller
Expansion
Check that electrical continuity is assured between the LCB housing and the premises
grounding system.
There are two ways to ensure proper grounding of the LCB depending on where it is installed:
1) Grounding is ensured by the four screws which secure the LCB on the rack if the frame of
the rack is connected to the premises ground system.
Safety
xxv