Calculating Power Requirements for the SRX5600 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 SRX5600 Firewall AC Power Supply Specifications and SRX5600 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.

Both normal-capacity and high-capacity SRX5600 chassis with DC power supplies are zoned, meaning that certain components are powered by specific power supplies (see Table 1 for information on zoning). When calculating power requirements, be sure that there is adequate power for each zone.

For an AC-powered chassis, there is one overall zone. Two AC power supplies are mandatory for high-line power, and three AC power supplies are mandatory for low-line power.

The SRX5600 Firewall chassis with AC power supplies has one overall zone. Two AC power supplies are mandatory for high-line power, and three AC power supplies are mandatory for low-line power.

Sample configuration for SRX5600 Firewall chassis with SRX5K-SCB (SCB1) and SRX5K-RE-13-20 (RE1):

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

• Switch control boards (SCBs) with one Routing Engine installed in SCB 0 and SCB 1.

• SRX5K-40GE-SFP I/O card (IOC).

• High-capacity cooling system

  Note:

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

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

   Table 2: Sample Power Requirements for an SRX5600 Firewall with SCB1 and RE1

   Chassis Component	Part Number	Power Requirement	Zone 0 Power	Zone 1 Power
   Base system	SRX5600BASE-HC-AC	40 W	20 W	20 W
   High-capacity cooling system	SRX5600-HC-FAN	160 W
   IOC - slot 0	SRX5K-40GE-SFP	365 W	365 W
   SPC - slot 1	SPC2	585 W	585 W
   SPC - slots 2 through 5	SPC2	585 W * 4 = 2340 W		2340 W
   SCB 0	SCB1 with RE1	150 W 90 W	240 W
   SCB 1	SCB1 without RE1	150 W	150 W
   Total power requirement		SRX5600 AC (not zoned) 3880 W
   Total power requirement excluding cooling system		SRX5600 AC (not zoned) 3720 W	Zone 0 total: 1360 W	Zone 1 total: 2360 W

2. Evaluate the power budget. In the case of a DC-powered chassis, evaluate the budget for each zone. In this step, we check the required power against the maximum output power of available power supply options.

   Note:

   The power for the cooling system comes from a different tap on the power supply, reserved for the cooling system only. The cooling system power requirement does not need to be deducted from the output power budget of the power supply.

   Table 3 lists the power supplies, their maximum output power, and unused power (or a power deficit) for an AC-powered firewall. Table 4 lists the power supplies, their maximum output power, and unused power (or a power deficit) for an DC-powered firewall.

   Table 3: Calculating Power Budget, AC-Powered Chassis with SCB1 and RE1

   Power Supply	Maximum Output Power of Power Supply	Maximum Output Power for System	Nonzoned Unused Power
   SRX5600 AC standard-capacity Note: SPC2 may require HC PEMs to operate	1027 W (low-line)	3081 W (3+1 Redundancy)	3081 W - 3880 W = -799 W Power Exceeded
   	1590 W (high-line)	4770 W (3+1 Redundancy)	4770 W- 3880 W = -890 W Power Exceeded
   SRX5600 AC high-capacity	1167 W (low-line)	3501 W (3+1 Redundancy)	3501 - 3880 = -379 W Power Exceeded
   	2050 W (high-line)	4100 W (2+1 or 2+2 Redundancy)	4100 - 3880 = 220 W

   Table 4: Calculating Power Budget, DC Powered Chassis with SCB1 and RE1

   Power Supply	Maximum Output Power of Power Supply	Maximum Output Power for System	Zone 0 Unused Power1	Zone 1 Unused Power2
   SRX5600 DC standard-capacity	1600 W	3200 W (1+1 Redundancy per zone)	1600 - 1360 = 240 W	1600 W - 2360 = -760 W Power exceeded
   SRX5600 DC high-capacity	2240 W (DIP=0)	4480 W (1+1 Redundancy per zone)	2240 - 1360 = 880 W	2240 W - 2360 = -120 W Power exceeded
   	2440 W (DIP=1)	4880 W (1+1 Redundancy per zone)	2440 - 1360 = 1080 W	2440 W - 2360 = 80 W

   ¹ For this configuration, zone 0 power requirement is 1360 W.

   ² For this configuration, zone 1 power requirement is 2360 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 5.Here we include the power drawn by the cooling system.

   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 5: Calculating System Input Power for SRX5600 Firewall with SCB1 and RE1

   Power Supply	Power Supply Efficiency1	Input Power Requirement
   SRX5600 AC standard-capacity	85 %	3880/0.85 = 4565 W
   SRX5600 AC high-capacity	89 %	3880/0.89 = 4360 W
   SRX5600 DC standard-capacity	~98 %	3880/0.98 = 3960 W
   SRX5600 DC high-capacity	~98 %	3880/0.98 = 3960 W

   ¹ These values are at full load and nominal voltage.

4. Calculate thermal output (BTUs) for the system. To calculate this value, multiply the total input power requirement (in watts) by 3.41 as shown in Table 6.

   Table 6: Calculating System Thermal Output for SRX5600 Firewall with SCB1 and RE1

   Power Supply	Thermal Output (BTUs per hour)
   SRX5600 AC standard-capacity	4565 * 3.41 = 15,566 BTU/hr
   SRX5600 AC high-capacity	4360 * 3.41 = 14,867 BTU/hr
   SRX5600 DC standard-capacity	3960 * 3.41 = 13,503 BTU/hr
   SRX5600 DC high-capacity	3960 * 3.41 = 13,503 BTU/hr

Sample configuration for SRX5600 Firewall chassis with SRX5K-SCBE (SCB2) and SRX5K-RE-1800X4 (RE2):

• Services Processing Card SPC2

• Switch control boards with one Routing Engine installed in SCB slot 0.

• SRX5K-MPC (IOC2) with fully loaded optical modules and two MICs such as:

  SRX-MIC-1X100G-CFP

  SRX-MIC-2X40G-QSFP

  SRX-MIC-10XG-SFPP (slot 0)

• High-capacity cooling system

  Note:

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

1. Calculate the power requirements (usage) as shown in Table 7.

   Table 7: Sample Power Requirements for an SRX5600 Firewall with SCB2 and RE2

   Chassis Component	Part Number	Power Requirement	Zone 0 Power	Zone 1 Power
   Base system	SRX5600BASE-HC-AC	40 W	20 W	20 W
   High-capacity cooling system	SRX5600-HC-FAN	160 W
   IOC - slot 0	IOC2	570 W	570 W
   SPC - slot 1	SPC2	585 W	585 W
   SPC - slots 2 through 5	SPC2	585 W * 4 = 2340 W		2340 W
   SCB 0	SCB2 with RE2	200 W 90 W	290 W
   SCB 1	SCB2	200 W	200 W
   Total power requirement		SRX5600 AC (not zoned) 4185 W
   Total power requirement excluding cooling system		SRX5600 AC (not zoned) 4025 W	Zone 0 total: 1665 W	Zone 1 total: 2360 W

2. Evaluate the power budget. In the case of a DC-powered chassis, evaluate the budget for each zone. In this step, we check the required power against the maximum output power of available power supply options.

   Note:

   The power for the cooling system comes from a different tap on the power supply, reserved for the cooling system only. The cooling system power requirement does not need to be deducted from the output power budget of the power supply.

   Table 8 lists the power supplies, their maximum output power, and unused power (or a power deficit) for an AC-powered firewall.Table 9 lists the power supplies, their maximum output power, and unused power (or a power deficit) for an DC-powered firewall.

   Table 8: Calculating Power Budget, AC-Powered Chassis with SCB2 and RE2

   Power Supply	Maximum Output Power of Power Supply	Maximum Output Power for System	Nonzoned Unused Power
   SRX5600 AC standard-capacity Note: SPC2 may require HC PEMs to operate	1027 W (low-line)	3081 W (3+1 Redundancy)	3081 W - 4025 W = -944 W Power Exceeded
   	1590 W (high-line)	4770 W (3+1 Redundancy)	4770 W- 4025 W = 745 W
   SRX5600 AC high-capacity	1167 W (low-line)	3501 W (3+1 Redundancy)	3501 - 4025 W = -524 W Power Exceeded
   	2050 W (high-line)	4100 W (2+2 Redundancy)	4100 - 4025 W = 75 W

   Table 9: Calculating Power Budget, DC Powered Chassis with SCB2 and RE2

   Power Supply	Maximum Output Power of Power Supply	Maximum Output Power for System	Zone 0 Unused Power1	Zone 1 Unused Power2
   SRX5600 DC standard-capacity	1600 W	3200 W (1+1 Redundancy per zone)	1600 W - 1665 W = -65 W	1600 W - 2360 = -760 W Power exceeded
   SRX5600 DC high-capacity	2240 W (DIP=0)	4480 W (1+1 Redundancy per zone)	2240 - 1665 W = 575 W	2240 W - 2360 = -120 W Power exceeded
   	2440 W (DIP=1)	4880 W (1+1 Redundancy per zone)	2440 - 1665 W = 775 W	2440 W - 2360 = 80 W

   ¹ For this configuration, zone 0 power requirement is 1665 W.

   ² For this configuration, zone 1 power requirement is 2360 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 10.Here we include the power drawn by the cooling system.

   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 10: Calculating System Input Power for SRX5600 Firewall with SCB2 and RE2

   Power Supply	Power Supply Efficiency1	Input Power Requirement
   SRX5600 AC standard-capacity	85 %	4185/0.85 = 4923 W
   SRX5600 AC high-capacity	89 %	4185/0.89 = 4702 W
   SRX5600 DC standard-capacity	~98 %	4185/0.98 = 4270 W
   SRX5600 DC high-capacity	~98 %	4185/0.98 = 4270 W

   ¹ These values are at full load and nominal voltage.

4. Calculate thermal output (BTUs) for the system. To calculate this value, multiply the total input power requirement (in watts) by 3.41 as shown in Table 11.

   Table 11: Calculating System Thermal Output for SRX5600 Firewall with SCB2 and RE2

   Power Supply	Thermal Output (BTUs per hour)
   SRX5600 AC standard-capacity	4923 * 3.41 = 16,787 BTU/hr
   SRX5600 AC high-capacity	4702 * 3.41 = 16,033 BTU/hr
   SRX5600 DC standard-capacity	4270 * 3.41 = 14,560 BTU/hr
   SRX5600 DC high-capacity	4270 * 3.41 = 14,560 BTU/hr

Sample configuration for SRX5600 Firewall chassis with SRX5K-SCB3 (SCB3) and RE2:

• Services Processing Card SPC2

• Switch control boards with one Routing Engine installed in SCB slot 0

• IOC3 (SRX5K-MPC3-40G10G or SRX5K-MPC3-100G10G)

• High-capacity cooling system

  Note:

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

1. Calculate the power requirements (usage) as shown in Table 12.

   Table 12: Sample Power Requirements for an SRX5600 Firewall with SCB3, IOC3, and RE2

   Chassis Component	Part Number	Power Requirement	Zone 0 Power	Zone 1 Power
   Base system	SRX5600BASE-HC-AC	40 W	20 W	20 W
   High-capacity cooling system	SRX5600-HC-FAN	160 W
   IOC - slot 0	IOC3	607 W	607 W
   SPC - slot 1	SPC2	585 W	585 W
   SPC - slots 2 through 5	SPC2	585 W * 4 = 2340 W		2340 W
   SCB 0	SCB3 with RE2	300 W 90 W	390 W
   SCB 1	SCB3	300 W	300 W
   Total power requirement		SRX5600 AC (not zoned) 4422 W
   Total power requirement excluding cooling system		SRX5600 AC (not zoned) 4262 W	Zone 0 total: 1902 W	Zone 1 total: 2360 W

2. Evaluate the power budget. In the case of a DC-powered chassis, evaluate the budget for each zone. In this step, we check the required power against the maximum output power of available power supply options.

   Note:

   The power for the cooling system comes from a different tap on the power supply, reserved for the cooling system only. The cooling system power requirement does not need to be deducted from the output power budget of the power supply.

   Table 13 lists the power supplies, their maximum output power, and unused power (or a power deficit) for an AC-powered firewall. Table 14 lists the power supplies, their maximum output power, and unused power (or a power deficit) for an DC-powered firewall.

   Table 13: Calculating Power Budget, AC-Powered Chassis with SCB3, IOC3, and RE2

   Power Supply	Maximum Output Power of Power Supply	Maximum Output Power for System	Nonzoned Unused Power
   SRX5600 AC standard-capacity Note: SPC2 may require HC PEMs to operate	1027 W (low-line)	3081 W (3+1 Redundancy)	3081 W - 4262 W = -1181W Power Exceeded
   	1590 W (high-line)	4770 W (3+1 Redundancy)	4770 W- 4262 W = 508 W
   SRX5600 AC high-capacity	1167 W (low-line)	3501 W (3+1 Redundancy)	3501 - 4262 W = -761 W Power Exceeded
   	2050 W (high-line)	6150 W (3+1 Redundancy)	6150 - 4262 W = 1888 W

   ¹ For this configuration, zone 0 power requirement is 1902 W.

   ² For this configuration, zone 1 power requirement is 2360 W.

   Table 14: Calculating Power Budget, DC Powered Chassis 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
   SRX5600 DC standard-capacity	1600 W	3200 W (1+1 Redundancy per zone)	1600 W - 1902 W = -302 W	1600 W - 2360 = -760 W Power exceeded
   SRX5600 DC high-capacity	2240 W (DIP=0)	4480 W (1+1 Redundancy per zone)	2240 - 1902 W = 338 W	2240 W - 2360 = -120 W Power exceeded
   	2440 W (DIP=1)	4880 W (1+1 Redundancy per zone)	2440 - 1902 W = 538 W	2440 W - 2360 = 80 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 15 .Here we include the power drawn by the cooling system.

   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 15: Calculating System Input Power for SRX5600 Firewall with SCB3, IOC3, and RE2

   Power Supply	Power Supply Efficiency1	Input Power Requirement
   SRX5600 AC standard-capacity	85 %	4422/0.85 = 5202 W
   SRX5600 AC high-capacity	89 %	4422/0.89 = 4968 W
   SRX5600 DC standard-capacity	~98 %	4422/0.98 = 4512 W
   SRX5600 DC high-capacity	~98 %	4422/0.98 = 4512 W

   ¹ These values are at full load and nominal voltage.

4. Calculate thermal output (BTUs) for the system. To calculate this value, multiply the total input power requirement (in watts) by 3.41 as shown in Table 16.

   Table 16: Calculating System Thermal Output for SRX5600 Firewall with SCB3, IOC3, and RE2

   Power Supply	Thermal Output (BTUs per hour)
   SRX5600 AC standard-capacity	5202 * 3.41 = 17,738 BTU/hr
   SRX5600 AC high-capacity	4968 * 3.41 = 16,940 BTU/hr
   SRX5600 DC standard-capacity	4512 * 3.41 = 15,385 BTU/hr
   SRX5600 DC high-capacity	4512 * 3.41 = 15,385 BTU/hr