EFJohnson 3000 SERIES - Manual (Page 175)

22-1
POWER SUPPLY
SECTION 22 POWER SUPPLY
22.1 INTRODUCTION
The Switch may be powered by different types of
power e.g.:
•
110V AC Single Phase
•
230V AC Single Phase
A power supply may be removed and installed
while power is applied to the Switch provided the
Switch is equipped with a Redundant Supply.
See Section 4 for a wiring diagram of the power
supplies.
22.2 POWER CONSUMPTION
The following tables shows the voltage, current
and power for each supply voltage per card (based on
loading of 72 cards).
Total watts including TIM-DID is 5.74W.
Excluding the TIM-DID provides a total of 4.3W for
normal modules. The following formulas are used to
find the BTUs per hour.
The total wattage of the terminal is found by
multiplying the wattage of a module by the number of
modules.
Total Watts x No. of Modules = Terminal Power
The wattage required by the power supply is
found by dividing the total wattage of the terminal by
the efficiency of the power supply (0.7).
Terminal Power
÷
0.7 = Wattage of Power Supply
The BTUs per hour are found by multiplying a known
value (3.6) by the wattage required by the power
supply.
3.6 x Wattage of Power Supply = BTU per hour
EXAMPLE:
4.3W x 72 = 310W
310W
÷
0.7 = 443W
3.6 x 443W = 1,595 Btu/Hr
Table 22-1 AVERAGE VOLTAGE/CURRENT/
POWER
Voltage Current Power
+5V DC 0.50A 2.50W
+12V DC 0.10A 1.20W
-12V DC 0.05A 0.60W
-48V DC 0.03A* 1.44W
Total 5.74W
* DIDs only.
Figure 22-1 POWER SUPPLY