Service manual

9-1
March 2000
Part No. 001-3139-502
POWER SUPPLIES
SECTION 9 POWER SUPPLIES
9.1 RECEIVER SITE POWER SUPPLY (-490)
The -490 Receiver Site Power Supply has a 110V
AC 50/60 Hz, 5A maximum input and 10 separate
13.8V DC/ground output connections.
9.2 RECEIVER SITE REDUNDANT KIT (-495)
The -495 Receiver Site Redundant Supply Kit
allows two power supplies to share the load.
9.3 VOTER SHELF POWER SUPPLY (-555)
The -555 Voter Shelf Power Supply has a 115/
230V AC 50/60 Hz input and 4 continuous duty out-
puts as follows:
+5V DC 24A.
-5V DC 6A.
+12V DC 3A.
-12V DC 5A.
The -555 power supply can handle 2 Voter
Shelves. The -555 has:
4 separate +5V 2A connections.
2 separate -5V connections.
2 separate +12V connections.
2 separate -12V connections.
6 separate ground connections.
9.4 VOTER POWER SUPPLY REDUNDANT
PLATE (-553)
The voter power supply drawer can be made
redundant by the use of the redundant diode plate. The
redundant plate allows two power supply drawers to
share the load via diodes. One of the power supply
drawers may be removed and the remaining drawer
will supply the full load. (See Figure 9-7.)
9.5 POWER CONSUMPTION
The voltage, current and power for each supply
voltage per card is shown in Table 9-1.
Total watts for a module is 6.03W. The following
formulas are used to find the BTUs per hour. The
total wattage of the voter system is found by multiply-
ing the wattage (6.03W) by the number of modules.
Watts x Number of Modules = Voter Power
The wattage required by the power supply is
found by dividing the total wattage of the Voter by the
efficiency (0.7) of the power supply.
Voter Power ÷ 0.7 = Wattage of the Power Supply
The BTUs per hour are found by multiplying a
known value (3.6) by the wattage of the power supply.
3.6 x Wattage of the Power Supply = BTU per hour
Example:
6.01 x 13 = 78.13W (Voter Power)
78.13 ÷ 0.7 = 111.6W (Wattage of the Power Supply)
3.6 x 111.6 = 401.76 BTUs per hour
Table 9-1 POWER CONSUMPTION
Voltage Current Power
+5V DC
-5V DC
+12V DC
-12V DC
0.80A
0.07A
0.08A
0.06A
4.00W
0.35W
0.96W
0.72W