Toshiba Strata DK 24, Руководство по установке и обслуживанию

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STRATA DK FAULT FINDING
SECTION 400-096-500
SEPTEMBER 1992
-4-
and Table H for digital telephones, DDSSs
and DDCBs.
7.20 Cable Installation
7.21 If cable voltmeter and ohmmeter tests are
within limits, digital telephones may not operate
because of the following:
1) Digital telephone cable runs must be free of
cable splits (single or double). Test for
and eliminate all cable splits.
2) Cable bridge taps - Digital telephones will
not operate if cable runs contain any type
(short or long) or cable bridge. Test for and
eliminate all cable bridges.
3) When installing the station cable, do not run
parallel to and within 3 feet of an AC power
line. AC power lines should be crossed at
right (90
°
) angles only. In particular, avoid
running station wire pairs near devices that
generate electrical noice, such as neon or
fluorescent light fixtures.
4) For the MDF-to-telephone (digital or elec-
tronic) cable, a more precise check is made
using an ohmmeter.
7.10 Ohmmeter Test
7.11 The continuity of the cable run between the
KSU and digital or electronic telephone is checked
with and ohmmeter as follows:
1) Disconnect the electronic 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 Figure 9-1 for electronic telephones or
Figure 9-22 for digital telephones).
4) At the modular block, measure the resis-
tance between all wire combinations. The
proper readings are shown in Table F for
electronic telephones, HDCBs and HDSSs,