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# Calculating Power Requirements for the SRX5800 Firewall

The information in this topic helps you determine which power supplies are suitable for various configurations, as well as which power supplies are not suitable because output power is exceeded. You determine suitability by subtracting the total power draw from the maximum output of the power supplies. Afterward, the required input current is calculated. Finally, you calculate the thermal output.

We recommend that you provision power according to the maximum input current listed in the power supply electrical specifications (see SRX5800 Firewall AC Power Supply Specifications and SRX5800 Firewall DC Power Supply Specifications).

Use the following procedures to calculate the power requirement:

1. Calculate the power requirement.

2. Evaluate the power budget.

3. Calculate input power.

4. Calculate thermal output (BTUs) for cooling requirements.

The SRX5800 Firewall chassis with normal-capacity AC power supplies has one overall zone. The SRX5800 Firewall Chassis with high-capacity AC power supplies or either standard- or high-capacity DC power supplies is zoned. Zoning means that certain components are powered by specific power supplies (see Table 1 and Figure 1 for information on zoning). When calculating power requirements, be sure that there is adequate power for each zone.

Three AC power supplies are mandatory for a SRX5800 Firewall chassis with normal-capacity AC power supplies.

Table 1: SRX5800 Firewall Zoning

Zone

Power Supply (PEM)

Components Receiving Power

Zone 0

PEM 0 or 2

• Bottom fan tray

• IOC/SPC slots 6 through 11

• SCB slots 1 through 2

Zone 1

PEM 1 or 3

• Upper fan tray

• IOC/SPC slots 0 through 5

• SCB slot 0

Figure 1: Power Distribution from DC and High-Capacity AC Power Supplies in the SRX5800 Firewall Chassis

Sample configuration for SRX5800 Firewall chassis with SRX5K-SCB (SCB1) and SRX5K-RE-13-20 (RE1) or with SRX5K-SCBE (SCB2) and SRX5K-RE-1800X4 (RE2):

• Four high-capacity AC power supplies (using two feeds for each power supply); two supplies are active, two are redundant.

• Two Switch Control Boards (SCBs) with Routing Engines.

• Two SRX5K-MPC (IOC2) Modular Port Concentrator, with two Modular Interface Cards (MICs).

• SRX5K-SPC-4-15-320 (SPC2) Services Processing Cards

Note:

You must have high-capacity power system (either AC or DC power supplies) and high-capacity cooling system (upper and bottom fan trays) installed in the firewall in order to install and use SPC2. If you do not have high-capacity power supplies and fan trays installed, the firewall will log an alarm condition when it recognizes the SPC.

• High-capacity cooling system (upper and bottom fan trays).

1. Calculate the power requirements (usage) as shown in Table 2.

Table 2: Sample Power Requirements for an SRX5800 Firewall with SRX5K-SCB (SCB1) and SRX5K-RE-13-20 (RE1) or with SRX5K-SCBE (SCB2) and SRX5K-RE-1800X4 (RE2)

Chassis Component

Part Number

Power Requirement

Zone 0 Power

Zone 1 Power

Base system

SRX5800BASE-HC-AC

50 W

25 W

25 W

High-capacity cooling system

SRX5800-HC-FAN

320 W * 2 = 640 W

320 W

320 W

SPC - slots 0 through 4

SPC2

585W * 5 = 2925 W

2925 W

MPC - slot 5

IOC2 with two MICs

570 W

570 W

SCB 0 - slot 0

SCB1 with RE1

or

SCB2 with RE2

150 W

90 W

240 W

SCB 1- slot 1

SCB1 with RE1

or

SCB2 with RE2

150 W

90 W

240 W

SCB 2/MPC - slot 2/6

IOC2 with two MICs

570 W

570 W

SPC - slots 7 through 11

SPC2

585W * 5 = 2925 W

2925 W

Total power requirement

SRX5800 high-capacity AC (not zoned) 8070 W

Zone 0 total: 4080 W

Zone 1 total: 4080 W

For the power consumption specifications of specific SRX5800 Firewall cards, see the SRX5400, SRX5600, and SRX5800 Firewall Card Guide at www.juniper.net/documentation/.

2. Evaluate the power budget, including the budget for each zone, if applicable. In this step, we check the required power against the maximum output power of available power supply options.

Table 3 lists the power supplies, their maximum output power, and unused power (or a power deficit).

Table 3: Calculating Power Budget for SRX5800 Firewall with SRX5K-SCB (SCB1) and SRX5K-RE-13-20 (RE1) or with SRX5K-SCBE (SCB2) and SRX5K-RE-1800X4 (RE2)

Power Supply

Maximum Output Power of Power Supply

Maximum Output Power for System

Zone 0 Unused Power1

Zone 1 Unused Power2

SRX5800 AC high-capacity

4100 W (two feeds)

8200 W (two feeds)

4100-4080=20 W

4100-4080=20 W

SRX5800 DC high-capacity

4100 W (two feeds)

8200 W (two feeds)

4100-4080=20 W

4100-4080=20 W

1 For this configuration, output power is 4080 W.

2 For this configuration, output power is 4080 W.

3. Calculate input power. In this step, the input power requirements for the example configuration are calculated. To do this, divide the total output requirement by the efficiency of the power supply as shown in Table 4 .

Table 4: Calculating Input Power for SRX5800 Firewall with SRX5K-SCB (SCB1) and SRX5K-RE-13-20 (RE1) or with SRX5K-SCBE (SCB2) and SRX5K-RE-1800X4 (RE2)

Power Supply

Power Supply Efficiency1

Input Power Requirement

SRX5800 AC high-capacity

~88 %

Zone 0: 4080/0.88= 4636 W

Zone 1: 4080/0.88= 4636 W

SRX5800 DC high-capacity

86 %

Zone 0: 4080/0.86= 4744 W

Zone 1: 4080/0.86= 4744 W

1 These values are at full load and nominal voltage.

4. Calculate thermal output (BTUs) for the system. To calculate this value, add the total input power requirement (in watts) for the two zones together and multiply the sum by 3.41 as shown in Table 5.

Table 5: Calculating Thermal Output for SRX5800 Firewall with SRX5K-SCB (SCB1) and SRX5K-RE-13-20 (RE1) or with SRX5K-SCBE (SCB2) and SRX5K-RE-1800X4 (RE2)

Power Supply

Thermal Output (BTUs per hour)

SRX5800 AC high-capacity

(4636 + 4636) * 3.41 = 31,617 BTU/hr

SRX5800 DC high-capacity

(4744 + 4744) * 3.41 = 32,354 BTU/hr

Sample configuration for SRX5800 Firewall chassis with SRX5K-SCB3 (SCB3) and SRX5K-RE-1800X4 (RE2):

• Four high-capacity AC power supplies (using two feeds for each power supply); two supplies are active, two are redundant.

• Two Switch Control Boards (SCBs) with Routing Engines.

• Two IOC3s (SRX5K-MPC3-40G10G and SRX5K-MPC3-100G10G) Modular Port Concentrator.

• SPC2 Services Processing Card

Note:

You must have high-capacity power supplies (either AC or DC) and high-capacity fan trays installed in the firewall in order to install and use SPC2. If you do not have high-capacity power supplies and fan trays installed, the firewall will log an alarm condition when it recognizes the SPC.

• High-capacity cooling system (upper and bottom fan trays).

1. Calculate the power requirements (usage) as shown in Table 6.

Table 6: Sample Power Requirements for an SRX5800 Firewall SCB3, IOC3, and RE2

Chassis Component

Part Number

Power Requirement

Zone 0 Power

Zone 1 Power

Base system

SRX5800BASE-HC-AC

50 W

25 W

25 W

High-capacity cooling system

SRX5800-HC-FAN

320 W * 2 = 640 W

320 W

320 W

SPC - slots 0 through 3

SPC2

585 W * 4= 2340 W

2340 W

slot 4

Empty

MPC - slot 5

SRX5K-MPC3-100G10G

607 W

607 W

SCB 0 - slot 0

SCB3 with RE2

185 W

90 W

275 W

SCB 1 - slot 1

SCB3 with RE2

185 W

90 W

275 W

SCB 2/MPC - slot 2/6

SRX5K-MPC3-40G10G

607 W

607 W

SPC - slots 7 through 10

SPC2

585 W * 4 = 2340 W

2340 W

slot 11

Empty

Total power requirement

SRX5800 high-capacity AC (not zoned) 7249 W

Zone 0 total: 3567 W

Zone 1 total: 3567 W

For the power consumption specifications of specific SRX5800 Firewall cards, see the SRX5400, SRX5600, and SRX5800 Firewall Card Guide at www.juniper.net/documentation/.

2. Evaluate the power budget, including the budget for each zone, if applicable. In this step, we check the required power against the maximum output power of available power supply options.

Table 7 lists the power supplies, their maximum output power, and unused power (or a power deficit).

Table 7: Calculating Power Budget for SRX5800 Firewall with SCB3, IOC3,and RE2

Power Supply

Maximum Output Power of Power Supply

Maximum Output Power for System

Zone 0 Unused Power1

Zone 1 Unused Power2

SRX5800 AC high-capacity

4100 W (two feeds)

8200 W (two feeds)

4100-3567=533 W

4100-3567=533 W

SRX5800 DC high-capacity

4100 W (two feeds)

8200 W (two feeds)

4100-3567=533 W

4100-3567=533 W

1 For this configuration, output power is 3567 W.

2 For this configuration, output power is 3567 W.

3. Calculate input power. In this step, the input power requirements for the example configuration are calculated. To do this, divide the total output requirement by the efficiency of the power supply as shown in Table 8.

Note:

Normal-capacity AC and DC power supplies are not included in the following table, because their power budget was exceeded in the sample configuration.

Table 8: Calculating Input Power for SRX5800 Firewall with SCB3, IOC3, and RE2

Power Supply

Power Supply Efficiency1

Input Power Requirement

SRX5800 AC high-capacity

~88 %

Zone 0: 3567/0.88= 4053 W

Zone 1: 3567/0.88= 4053 W

SRX5800 DC high-capacity

86 %

Zone 0: 3567/0.86= 4147 W

Zone 1: 3567/0.86= 4147 W

1 These values are at full load and nominal voltage.

4. Calculate thermal output (BTUs) for the system. To calculate this value, add the total input power requirement (in watts) for the two zones together and multiply the sum by 3.41 as shown in Table 9 .

Table 9: Calculating Thermal Output for SRX5800 Firewall with SCB3, IOC3, and RE2

Power Supply

Thermal Output (BTUs per hour)

SRX5800 AC high-capacity

(4053 + 4053) * 3.41 = 27,641 BTU/hr

SRX5800 DC high-capacity

(4147 + 4147) * 3.41 = 28,282 BTU/hr

Sample configuration for SRX5800 Firewall chassis with six SRX5K-SPC-2-10-40 (SPC2), one SRX5K-SPC3 (SPC3), three SRX5K-IOC4-10G, and two SRX5K-SCB4s (SCB4) with two SRX5K-RE3-128Gs (RE3):

• Four high-capacity AC power supplies (using two feeds for each power supply); two supplies are active, two are redundant.

• Two SRX5K-SCB4s (SCB4) with two SRX5K-RE3-128Gs (RE3) installed in slot number SCB 0 and SCB 1 of the chassis.

Note:

The two SCB4s fabric mode must be changed from default fabric mode to redundant fabric mode.

• Three SRX5K-IOC4-10Gs (IOC4) Modular Port Concentrator

• Six SPC2s & one SPC3 Services Processing Cards

Note:

You must have high-capacity power supplies (either AC or DC) and high-capacity fan trays installed in the firewall in order to install and use SPC2 and SPC3. If you do not have high-capacity power supplies and fan trays installed, the firewall will log an alarm condition when it recognizes the SPC.

• High-capacity cooling system (upper and bottom fan trays)

1. Calculate the power requirements (usage) as shown in Table 10.

Table 10: Sample Power Requirements

Chassis Component

Part Number

Power Requirement

Zone 0 Power

Zone 1 Power

Base system

SRX5800BASE-HC-AC

50 W

25 W

25 W

High-capacity cooling system

SRX5800-HC-FAN

320 W * 2 = 640 W

320 W

320 W

SPC - slots 0

SPC3

650 W

650 W

SPC - slots 1 through 3

SPC2

585 W * 3= 1755 W

1755 W

slot 4

Empty

MPC - slot 5

SRX5K-IOC4-10G

500 W

500 W

SCB 0 (For Zone 1)

SCB4 with RE3

425 W

110 W

535 W

SCB 1 (For Zone 0)

SCB4 with RE3

425 W

110 W

535 W

MPC - SCB 2 / slot 6

SRX5K-IOC4-10G

500 W

500 W

MPC - slot 7

SRX5K-IOC4-10G

500 W

500 W

SPC - slots 8 through 10

SPC2

585 W * 3= 1755 W

1755 W

slot 11

Empty

Total power requirement

SRX5800 (not zoned) 7420 W

Zone 0 total: 3635 W

Zone 1 total: 3785 W

2. Evaluate the power budget, including the budget for each zone, if applicable. In this step, we check the required power against the maximum power output of the available power supply options.

Table 11 lists the power supplies, their maximum power output, and unused power (or a power deficit).

Table 11: Calculating Power Budget

Power Supply

Maximum Power Output of a Power Supply

Maximum Power Output of a System

Zone 0 Unused Power1

Zone 1 Unused Power2

SRX5800 AC high-capacity

4100 W (with two feeds)

8200 W (2+2 with two feeds)

4100-3635=465 W unused power

4100-3785=315 W unused power

SRX5800 DC high-capacity

4100 W (with two feeds)

8200 W (2+2 with two feeds)

4100-3635=465 W unused power

4100-3785=315 W unused power

1 For this configuration, power output is 3635 W.

2 For this configuration, power output is 3785 W.

3. Calculate input power. In this step, the input power requirements for the example configuration are calculated. To do this, divide the total power output requirement by the efficiency of the power supply as shown in Table 12.

Table 12: Calculating Input Power

Power Supply

Power Supply Efficiency1

Input Power Requirement

SRX5800 AC high-capacity

~88 %

Zone 0: 3635/0.88= 4131 W

Zone 1: 3785/0.88= 4301 W

SRX5800 DC high-capacity

86 %

Zone 0: 3635/0.86= 4227 W

Zone 1: 3785/0.86= 4401 W

1 These values are at full load and nominal voltage.

4. Calculate thermal output (BTUs) for the system. To calculate this value, add the total input power requirement (in watts) for the two zones together and multiply the sum by 3.41 as shown in Table 13 .

Table 13: Calculating Thermal Output

Power Supply

Thermal Output (BTUs per hour)

SRX5800 AC high-capacity

(4131 + 4301) * 3.41 = 18,797 BTU/hr

SRX5800 DC high-capacity

(4227 + 4401) * 3.41 = 19,234 BTU/hr

Sample configuration for SRX5800 Firewall chassis with six SRX5K-SPC-2-10-40 (SPC2), one SRX5K-SPC3 (SPC3), three SRX5K-IOC4-MRAT, and two SRX5K-SCB4s (SCB4) with two SRX5K-RE3-128Gs (RE3):

• Four high-capacity AC power supplies (using two feeds for each power supply); two supplies are active, two are redundant.

• Two SRX5K-SCB4s (SCB4) with two SRX5K-RE3-128Gs (RE3) installed in slot number SCB 0 and SCB 1 of the chassis.

Note:

The two SCB4s fabric mode must be changed from default fabric mode to redundant fabric mode.

• Three SRX5K-IOC4-MRATs (IOC4) Modular Port Concentrator

• Six SPC2s & one SPC3 Services Processing Cards

Note:

You must have high-capacity power supplies (either AC or DC) and high-capacity fan trays installed in the firewall in order to install and use SPC2 and SPC3. If you do not have high-capacity power supplies and fan trays installed, the firewall will log an alarm condition when it recognizes the SPC.

• High-capacity cooling system (upper and bottom fan trays)

Note:

The high-capacity cooling system satisfies cooling requirements of SPC2 & SPC3 and must be used for proper cooling.

1. Calculate the power requirements (usage) as shown in Table 14.

Table 14: Sample Power Requirements

Chassis Component

Part Number

Power Requirement

Zone 0 Power

Zone 1 Power

Base system

SRX5800BASE-HC-AC

50 W

25 W

25 W

High-capacity cooling system

SRX5800-HC-FAN

320 W * 2 = 640 W

320 W

320 W

SPC - slots 0

SPC3

650 W

650 W

SPC - slots 1 through 3

SPC2

585 W * 3= 1755 W

1755 W

slot 4

Empty

MPC - slot 5

SRX5K-IOC4-MRAT

545 W

545 W

SCB 0 (For Zone 1)

SCB4 with RE3

425 W

110 W

535 W

SCB 1 (For Zone 0)

SCB4 with RE3

425 W

110 W

535 W

MPC - SCB 2 / slot 6

SRX5K-IOC4-MRAT

545 W

545 W

MPC - slot 7

SRX5K-IOC4-MRAT

545 W

545 W

SPC - slots 8 through 10

SPC2

585 W * 3= 1755 W

1755 W

slot 11

Empty

Total power requirement

SRX5800 (not zoned) 7555 W

Zone 0 total: 3725 W

Zone 1 total: 3830 W

2. Evaluate the power budget, including the budget for each zone, if applicable. In this step, we check the required power against the maximum power output of the available power supply options.

Table 15 lists the power supplies, their maximum power output, and unused power (or a power deficit).

Table 15: Calculating Power Budget

Power Supply

Maximum Power Output of a Power Supply

Maximum Power Output of a System

Zone 0 Unused Power1

Zone 1 Unused Power2

SRX5800 AC high-capacity

4100 W (with two feeds)

8200 W (2+2 with two feeds)

4100-3725=375 W unused power

4100-3830=270 W unused power

SRX5800 DC high-capacity

4100 W (with two feeds)

8200 W (2+2 with two feeds)

4100-3725=375 W unused power

4100-3830=270 W unused power

1 For this configuration, power output is 3725 W.

2 For this configuration, power output is 3830 W.

3. Calculate input power. In this step, the input power requirements for the example configuration are calculated. To do this, divide the total power output requirement by the efficiency of the power supply as shown in Table 16.

Table 16: Calculating Input Power

Power Supply

Power Supply Efficiency1

Input Power Requirement

SRX5800 AC high-capacity

~88 %

Zone 0: 3725/0.88= 4233 W

Zone 1: 3830/0.88= 4352 W

SRX5800 DC high-capacity

86 %

Zone 0: 3725/0.86= 4331 W

Zone 1: 3830/0.86= 4453 W

1 These values are at full load and nominal voltage.

4. Calculate thermal output (BTUs) for the system. To calculate this value, add the total input power requirement (in watts) for the two zones together and multiply the sum by 3.41 as shown in Table 17 .

Table 17: Calculating Thermal Output

Power Supply

Thermal Output (BTUs per hour)

SRX5800 AC high-capacity

(4233 + 4352) * 3.41 = 19,073 BTU/hr

SRX5800 DC high-capacity

(4331 + 4453) * 3.41 = 19,516 BTU/hr