ADC Telecommunications Inc. DISSMRAA Benutzerhandbuch
ADCP-75-136
• Issue 1 • November 2002
Page 53
©
2002, ADC Telecommunications, Inc.
3. Connect the DC power cable to the RJ-45 circuit access tool (see Figure 28).
4. Using a DC voltmeter, verify that the DC voltage level is between 34 and 48 Vdc
4. Using a DC voltmeter, verify that the DC voltage level is between 34 and 48 Vdc
between
any set of positive and negative (+/-) terminals at the RJ-45 circuit access tool
as
shown in Figure 29. Due to source current limiting at the DHU or DEU, low voltage
can
mean excess wire resistance, low source voltage, or excess remote current.
Warning: The DRU uses 48 Vdc power. To avoid electric shock or burns, use extreme care
when
working near exposed terminals or uninsulated cables. Be careful not to touch exposed
terminals
or to cause a short between terminals when checking voltage levels.
16206-B
POSITIVE (+)
TEST POINTS
1, 3, 5, AND 7
NEGATIVE (-)
TEST POINTS
2, 4, 6, AND 8
Figure 29. RJ-45 Circuit Access Tool Pin/Wire Designations
5. Disconnect RJ-45 circuit access tool from the DRU.
6. Use the DC voltmeter to check for open pin connections by checking for voltage between
6. Use the DC voltmeter to check for open pin connections by checking for voltage between
the
+/– pairs on the RJ-45 circuit access tool (see Figure 29).
7. Disconnect the DC power cable from the RJ-45 circuit access tool.
8. Re-connect DC power cable to the DRU.
8. Re-connect DC power cable to the DRU.
6.5 DHU or DEU Fan Replacement Procedure
It
is recommended that the fans (catalog # DGVI-100000FAN) be replaced every five years.
Replacement
of a fan requires that the DHU or DEU be turned off for a short period of time. This
will
drop all existing calls, cause a temporary loss of service, and generate a major alarm. Use the
following
procedure to replace the cooling fans within the DHU or the DEU:
1. Before touching the DHU or DEU or handling a fan, slip on an Electro-Static Discharge
(ESD)
wrist strap and connect the ground wire to an earth ground source. Wear the ESD
wrist
strap while completing each section of the fan installation procedure.
Warning: Electronic components can be damaged by static electrical discharge. To prevent
ESD
damage, always wear an ESD wrist strap when working on the DHU or DEU and when
handling
electronic components.
2. Observe the fans (located on right side of enclosure) to determine which fan requires
replacement.
The faulty fan may be stopped, running at a reduced speed, or the fan
bearing
may be noisy.
Note: Because the Mean Time Between Failures (MBTF) is the same for both fans, it may be
more
efficient to replace both fans at the same time.
FCC ID: F8I-DISSMRAA, Partial User Manual, 4 of 4