User Manual
DC Power Pre-test68P09255A57-2
Aug 2002
SC4812ET Optimization/ATP Manual Software Release R16.1.x.x
PRELIMINARY
2-9
Table 2-6: DC Power Pre-test (BTS Frame)
Step Action
7 Set the 8 LPA breakers ON by pushing them IN one at a time. Repeat step 3 after turning on each
breaker.
A typical response is that the ohmmeter will steadily climb in resistance as capacitors charge,
stopping at approximately 500
Ω..
8 Seat all LPA and associated LPA fan modules into their associated slots in the shelves one at a time.
Repeat step 3 after seating each LPA and associated LPA fan module.
A typical response is that the ohmmeter will steadily climb in resistance as capacitors charge,
stopping at approximately 500
Ω..
9 Seat the Heat Exchanger, ETIB, and Options breakers one at a time. Repeat step 3.
RF Cabinet Power Up
Table 2-7 covers the procedures for properly powering up the RF
Cabinet.
Table 2-7: RF Cabinet Power Up
Step Action
1 Ensure the 400 Amp Main DC breaker and all other breakers in the RF Cabinet are OFF.
2 Proceed to the DC Power Pre-test (BTS Frame) sequence (see Table 2-6) (for initial power-up as
required).
3 Ensure the power cabinet is turned on (see Table 2-5). Verify that 27 volts is applied to the terminals
on the back of the RF cabinet.
4 Engage the main DC circuit breaker on the RF cabinet (see Figure 2-5).
5 On each RF cabinet:
Set C-CCP shelf breakers to the ON position by pushing them in one at a time (labeled
C-CCP 1, 2, 3 - located on the power distribution panel).
Set LPA breakers to the ON position by pushing them in one at a time (8 breakers, labeled 1A-1B
through 4C-4D - located on the power distribution panel).
Set the two heat exchanger breakers to the ON position by pushing them in one at a time.
Set the ETIB breaker to the ON position by pushing it in.
Set the OPTION breaker to the ON position by pushing it in.
6 Measure the voltage drop between the Power Cabinet meter test point and the 27 V buss bar inside the
RF Cabinet PDA while the RF Cabinet is transmitting.
NOTE
For a 3-sector carrier system, the voltage drop should be less than 0.2 V.
For a 12-sector carrier system, the voltage drop should be less than 0.3 V.
7 Using a DC current probe, measure the current in each of the six (6) DC cables that are connected
between the RF and Power Cabinet. The DC current measured should be approximately the same. If
there is a wide variation between one cable and the others (>20 A), check the tightness of the
connections (torque settings) at each end of the cable.
2