Station Cable Continuity Check; Voltmeter Test - Toshiba strata CT Installation & Maintenance Manual

Fault Finding

Station Cable Continuity Check

Voltmeter Test

Use a voltmeter to check cable continuity between the Strata CT cabinet, digital or electronic
telephone, DSS console, and the attendant console. Make tests at the modular block. Refer to
Tables 8-1
➤
To perform the voltmeter test
1.
2.
3.
4.
H
5.
Table 8-1 Station Cable Continuity Check for Digital Telephone Cables using Voltmeter
Pair
C
1
1
1
1
1
2
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.
8-4
and 8-2.
Refer to Chapter 4 – Universal Slot PCB Wiring
Disconnect the digital or electronic telephone, DSS console, PDIU-DS, HDCB, or
DDCB.
Using a DC voltmeter, measure between the wires of the two pairs to verify the readings
shown in Table 8-1 for digital telephone ports. Refer to
telephone ports. The reading will be a plus or minus depending on meter lead
placement.
An improper reading indicates an open, crossed or shorted wire. See
(BPSU672F) Removal" on Page 2-8
For the MDF-to-telephone (digital or electronic) cable, use an ohmmeter to make a
more precise check.
From
Wire Colour
1
T Green
R Red
T Green
R Red
T Green
T Black
± ±
26.3 ~
for appropriate MDF wiring diagrams.
and "Power Supply Replacement" on Page
To
Pair Wire
2 T
2 T
2 R
2 R
1 R
2 R
27.8VDC while under AC power, polarity depending on voltmeter
Table 8-2 for electronic
"Power Supply
Colour
Black
Black
Yellow
Yellow
Red
Yellow
Strata CT I&M Manual October 2000
2-8.
Voltage
0
2
24
2
24
0
2
24
2
24