Ohmmeter Test - Toshiba strata CT Installation & Maintenance Manual

Table 8-2
Pair
1
1
1
1
1
2
3
3
3
3
H
3
3
3
3
3
C
1.
The green-red, black-yellow and white-blue measurements should be within 10% of each other.
2.
Nominal voltage—within limits of
lead placements.

Ohmmeter Test

➤
To perform the ohmmeter test
Strata CT I&M Manual October 2000
Station Cable Continuity Check for Electronic Telephone Cables using
Voltmeter
From
Wire Colour
T Green
R Red
T Green
R Red
T Green
T Black
T White
T White
R Blue
T White
R Blue
T White
R Blue
T White
R Blue
26.3 ~
±
Check the continuity of the cable run between the KSU/cabinet and digital or electronic
telephone with an ohmmeter.
1. Disconnect the DSS console, electronic or digital telephone.
2. At the MDF, remove the bridging clips.
3. At the MDF, place shorting jumper wires between the T and R of pair #1 (green-red),
the T and R of pair #2 (black-yellow) and the T and R of OCA pair #3 (blue-white), for
PEKU/PESU only. (For MDF pin numbers, see
Wiring.)
4. At the modular block, measure the resistance between all wire combinations. The
proper readings are shown in
Table 8-4 for electronic telephones and HDSSs.
5. An improper reading indicates an open, crossed or shorted wire. See
(BPSU672F) Removal" on Page 2-8
Pair
1
2
2
2
2
1
2
3
1
1
1
1
2
2
2
2
27.8VDC while under AC power, polarity depending on voltmeter
±
Table 8-3 for digital telephones, DDSSs, DDCBs and
and "Power Supply Replacement" on Page
To
Wire Colour
T Black
T Black
R Yellow
R Yellow
R Red
R Yellow
R Blue
R Red
R Red
T Green
T Green
T Black
T Black
R Yellow
R Yellow
Chapter 4 – Universal Slot PCB
"Power Supply
Fault Finding
Voltage
2
24
2
24
2
24
2
24
0
0
0
0
0
0
0
0
0
0
0
2-8.
8-5