Toshiba Strata CT, Инструкция по установке и обслуживанию

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Fault Finding
Strata CT I&M Manual October 2000
8-5
Ohmmeter Test
Check the continuity of the cable run between the KSU/cabinet and digital or electronic
telephone with an ohmmeter.
➤
To perform the ohmmeter test
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
Chapter 4 – Universal Slot PCB
Wiring .)
4. At the modular block, measure the resistance between all wire combinations. The
proper readings are shown in
Table 8-3 for digital telephones, DDSSs, DDCBs and
Table 8-4 for electronic telephones and HDSSs.
5. An improper reading indicates an open, crossed or shorted wire. See “Power Supply
(BPSU672F) Removal” on Page 2-8 and “Power Supply Replacement” on Page 2-8 .
Table 8-2 Station Cable Continuity Check for Electronic Telephone Cables using
Voltmeter
From To
Voltage
Pair Wire Colour Pair Wire Colour
1 T Green
1
1. The green-red, black-yellow and white-blue measurements should be within 10% of each other.
2 T Black 24
2
2.
Nominal voltage—within limits of ± 26.3 ~ ± 27.8VDC while under AC power, polarity depending on voltmeter
lead placements.
1 R Red 2 T Black 24
2
1 T Green 2 R Yellow 24
2
1 R Red 2 R Yellow 24
2
1 T Green 1 R Red 0
2 T Black 2 R Yellow 0
3 T White 3 R Blue 0
3 T White 1 R Red 0
3 R Blue 1 R Red 0
3 T White 1 T Green 0
3 R Blue 1 T Green 0
3 T White 2 T Black 0
3 R Blue 2 T Black 0
3 T White 2 R Yellow 0
3 R Blue 2 R Yellow 0
H
C