Cabinet Removal And Replacement-Floor Mounted Systems; Grounding Requirements; 3.6.1 Third Wire Ground Test - Toshiba Strata DK 280 Installation Manual

3.5.3 Cabinet Removal and Replacement-
Floor
Mounted Systems
Cabinet Removal
Use the following procedure to remove a cabinet from
a floor mounted system: (This procedure is written on
the presumption that the base cabinet is the bottom
cabinet of systems with two or more cabinets.)
1. Turn the system power
and side covers from the cabinet to be replaced
and any cabinets above it. Remove the top cover
from the top cabinet if it is to be replaced (Figure
3-1).
2. Unplug the AC power cord of the cabinet and any
reserve power cabling connected to the power
supply. Repeat this procedure for each cabinet
above the cabinet to be replaced.
3. If a power strip (RPSB1) (Figure 3-20), Conduit
Connection Box (RCCBI), or Battery Distribution
Box (RBDBl) is connected to the cabinet, remove
them (Figures 3-22 and 3-24).
4. If the cabinet to be replaced is the base cabinet
connected to the base cabinet data cable
connector.
5. If the cabinet to be replaced is an expansion
cabinet (DKSUE280 or DKSUE424), disconnect
the data cable of the cabinet from the data cable
connector on the base cabinet. Repeat this
procedure for all expansion cabinets above the
cabinet to be replaced.
Disconnect any intercabinet ground wiring or
6.
system ground wiring connected to the cabinet.
Repeat this procedure for any cabinets above the
cabinet to be replaced.
7. Remove any cabinets above the cabinet to be
replaced, and then remove the cabinet to b e
replaced.
Cabinet Replacement
Subsection 3.5.1. For systems with three or more
cabinets that are bolted to the floor (Method l ) , refer
to Subsection 3.5.2. For systems with three or more
cabinets that are not bolted to the floor (Method 2),
refer to Subsection 3.5.2.
3-26
off, and remove the front
3.6

Grounding Requirements

The system requires a solid earth ground for proper
operation and safety. Failure to provide ground may
be a safety hazard or lead to confusing trouble
symptoms and, in extreme cases, system failure. The
AC power cord(s) already contains a conductor for the
"third wire ground provided by the commercial power
outlet. It is also necessary to connect an insulated
conductor between the frame ground terminal on the
base cabinet (or the bottom expansion cabinet) and a
cold water pipe or the building ground (Figure 3-1
Notes:
The "third wire ground ('A" in Figure 3-
1.
19) must be dedicated.
2. The conductor connected to the frame
ground r A " in Figure
with the general rules for grounding
contained in Article 250
Electrical Code, NFPA
depend on the cord and plug of the
system.

3.6.1 Third Wire Ground Test

Test each "third wire ground" separately for continuity
by either measuring the resistance between the third
prong terminal (earth ground) and a metal cold water
pipe (maximum: 1 ohm) or by using a commercially
available earth ground indicator. If neither procedure is
possible, perform the following procedure.
WARNING!
Hazardous voltages that may cause death
or injury are exposed during the following
test. Use great care when working with AC
power line voltage.
Obtain suitable voltmeter, and set
reading of up to 250VAC.
2. Connect the meter probes between the two main
AC voltage terminals (white and black wires) on
the wall outlet. The reading obtained should be
-
between 100
3. Move one of the meter probes to the third terminal
(green wire ground, point A in Figure 3-19). Either
the same reading or a reading of zero volts should
be obtained.
.
9).
must comply
19)
of the National
but must not
70,
for a possible
it
January 1996