How do I calculate the power and current requirements for an MSE 8000?

Chassis calculator

Chassis calculator

Use this calculator to determine the power requirements for your MSE 8000 chassis and blades. (To calculate power requirements manually, see the information later in this article.)

Slot 1: MSE 8050 - Supervisor
Slot 2:

Slot 3:

Slot 4:

Slot 5:

Slot 6:

Slot 7:

Slot 8:

Slot 9:

Slot 10:

If you know the efficiency of your rectifier, enter the value here to find AC power and current. For example, for 90% efficiency, enter the value 90:

%

Calculator results

The results are as follows (values are rounded up):

Requirements

Value

DC power (Watts)

DC current (Amps)

Rectifiers required per power shelf

Calculator results for AC power

Using the rectifier efficiency value that you entered above, the AC power and current results are as follows:

Requirements

Value

AC power (Watts)

240V P.S.U. current draw (Amps)

110V P.S.U. current draw (Amps)

Understanding power requirements

The power requirements for an MSE 8000 chassis vary significantly depending on the number of blades installed and their individual power requirements. For example, a chassis that is fully loaded (nine MSE 8510 Media2 blades) would require 4kW of power. In contrast, a chassis that is minimally loaded with one MSE 8420 Media blade would require 0.52kW of power.

Each blade and fan tray has a power requirement figure, which is available from a label on the blade or from the following table.

Model number

DC current (Amps)

DC power (Watts)

MSE 8010 - Fan Tray

3.5

168

MSE 8050 - Supervisor

1.3

62.4

MSE 8220 - VCR

1.3

62.4

MSE 8310 - ISDN4

1.3

62.4

MSE 8321 - ISDN8

1.3

62.4

MSE 8330 - Serial GW

1.3

62.4

MSE 8420 - Media

1.3

62.4

MSE 8510 - Media2

7.3

350.4

MSE 8710 - Telepresence

7.3

350.4

Media 820 - Telepresence

7.9

379.2

Calculating the current draw from a 48V DC power supply unit

To calculate the current that will be drawn from your 48V DC power supply unit:

Use the table above to find the DC current requirement for each blade and fan tray to be installed in your MSE 8000.

Sum these figures to give a total DC current requirement.

Example. The current drawn in the instance outlined above would be:

1.3 + 3.5 + 3.5 + 7.3 + 7.3 + 1.3 = 24.2 Amps

So the total current drawn will be approximately 25 Amps.

Calculating the number of rectifiers needed

To calculate the number of rectifiers needed:

Calculate your total DC current requirements using the information above.

Use the following table to determine the number of rectifiers required:

Total DC current requirement (Amps)

Rectifiers required per power shelf

20

1

40

2

60

3

80

4

Example. In the chassis example detailed above, there was a total DC current of 25 Amps meaning that two rectifiers would be needed per power shelf.