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Calculating Power Requirements for the SRX5800 Services Gateway

 

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 Services Gateway AC Power Supply Specifications and SRX5800 Services Gateway 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 Services Gateway chassis with normal-capacity AC power supplies has one overall zone. The SRX5800 Services Gateway 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 Services Gateway chassis with normal-capacity AC power supplies.

Table 1: SRX5800 Services Gateway Zoning

Zone

Power Supply (PEM)

Components Receiving Power

Zone 0

PEM 0 or 2

  • Lower 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 Services Gateway Chassis
Power Distribution
from DC and High-Capacity AC Power Supplies in the SRX5800 Services
Gateway Chassis

Sample configuration for SRX5800 Services Gateway chassis with SRX5K-SCB (SCB1) and SRX5K-RE-13-20 (RE1):

  • 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 one Routing Engine installed in SCB 0

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

  • One SRX5K-40GE-SFP I/O card (IOC)

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

    Note

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

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

    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 and Table 6.

    Table 2: Sample Power Requirements for an SRX5800 Services Gateway with SCB1 and RE1

    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

    See note below.

    585W * 5 = 2925 W

     

    2925 W

    MPC - slot 5

    IOC2 with two MICs

    570 W

     

    570 W

    SCB 0 - slot 6

    SCB1 with

    RE1

    150 W

    90 W

     

    240 W

    SCB 1- slot 7

    SCB1

    150 W

    150 W

     

    MPC - slot 8

    IOC2 with two MICs

    570 W

    570 W

    SPC - slots 9 through 13

    SPC2

    See note below.

    585W * 5 = 2925 W

    2925 W

     

    Total power requirement

    SRX5800 standard-capacity AC (not zoned) 8070 W

    Zone 0 total: 3990 W

    Zone 1 total: 4080 W

    For the power consumption specifications of specific SRX5800 services gateway cards, see the SRX5400, SRX5600, and SRX5800 Services Gateway 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 Services Gateway with SCB1 and RE1

    Power Supply

    Maximum Output Power of Power Supply

    Maximum Output Power for System

    Nonzoned Unused Power

    Zone 0 Unused Power1

    Zone 1 Unused Power2

    SRX5800 AC standard-capacity

    1700 W

    5100 W

    Power exceeded (non-zoned; 5100 W - 8070 W = -2970 W power exceeded)

    SRX5800 AC high-capacity

    1700 W (one feed)

    4100 W (two feeds)

    3400 W (one feed)

    8200 W (two feeds)

    Power exceeded

    4100-3990=110 W

    Power exceeded

    4100-4080=20 W

    SRX5800 DC normal-capacity

    2800 W

    5600 W

    Power exceeded

    Power exceeded

    SRX5800 DC high-capacity

    1700 W (one feed)

    4100 W (two feeds)

    3400 W (one feed)

    8200 W (two feeds)

    Power exceeded

    4100-3990=110 W

    Power exceeded

    4100-4080=20 W

    1 For this configuration, output power is 3990 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 .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 4: Calculating Input Power for SRX5800 Services Gateway with SCB1 and RE1

    Power Supply

    Power Supply Efficiency1

    Input Power Requirement

    SRX5800 AC high-capacity

    ~88 %

    Zone 0: 3990/0.88= 4534 W

    Zone 1: 4080/0.88= 4636 W

    SRX5800 DC high-capacity

    86 %

    Zone 0: 3990/0.86= 4639 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 Services Gateway with SCB1 and RE1

    Power Supply

    Thermal Output (BTUs per hour)

    SRX5800 AC high-capacity

    (4534 + 4636) * 3.41 = 31,269 BTU/hr

    SRX5800 DC high-capacity

    (4639 + 4744) * 3.41 = 31,996 BTU/hr

Sample configuration for SRX5800 Services Gateway chassis 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 one Routing Engine installed in SCB 0

  • IOC2 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 services gateway in order to install and use SPC2. If you do not have high-capacity power supplies and fan trays installed, the services gateway will log an alarm condition when it recognizes the SPC.

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

    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 6.

    Table 6: Sample Power Requirements for an SRX5800 Services Gateway SCB2 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 4

    SPC2

    See note below.

    585 W * 5= 2925 W

     

    2925 W

    MPC - slot 5

    IOC2 with two MICs

    570 W

     

    570 W

    SCB 0 (slot 6 for Zone 1)

    SCB2 with RE2

    200 W

    90 W

    290 W

    SCB 1 (slot 7 for Zone 0)

    SCB2

    200 W

    200 W

    MPC - slot 8

    IOC2 with two MICs

    570 W

    570 W

    SPC - slots 9 through 13

    SPC2

    See note below.

    585 W * 5 = 2925 W

    2925 W

    Total power requirement

    SRX5800 standard-capacity AC (not zoned) 8170 W

    Zone 0 total: 4040 W

    Zone 1 total: 4130 W

    For the power consumption specifications of specific SRX5800 services gateway cards, see the SRX5400, SRX5600, and SRX5800 Services Gateway 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 Services Gateway with SCB2 and RE2

    Power Supply

    Maximum Output Power of Power Supply

    Maximum Output Power for System

    Nonzoned Unused Power

    Zone 0 Unused Power1

    Zone 1 Unused Power2

    SRX5800 AC standard-capacity

    1700 W

    5100 W

    Power exceeded (non-zoned; 5100 W - 8170 W = -3070 W power exceeded)

    SRX5800 AC high-capacity

    1700 W (one feed)

    4100 W (two feeds)

    3400 W (one feed)

    8200 W (two feeds)

    Power exceeded

    4100-4040=60 W

    Power exceeded

    4100-4130=-30 W

    Note: Power is exceeded. Therefore, there is not enough power to cover redundancy with this configuration.

    SRX5800 DC normal-capacity

    2800 W

    5600 W

    Power exceeded

    Power exceeded

    SRX5800 DC high-capacity

    1700 W (one feed)

    4100 W (two feeds)

    3400 W (one feed)

    8200 W (two feeds)

    Power exceeded

    4100-4040=60 W

    Power exceeded

    4100-4130=-30 W

    Note: Power is exceeded. Therefore, there is not enough power to cover redundancy with this configuration.

    1 For this configuration, output power is 4040 W.

    2 For this configuration, output power is 4130 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 Services Gateway with SCB2 and RE2

    Power Supply

    Power Supply Efficiency1

    Input Power Requirement

    SRX5800 AC high-capacity

    ~88 %

    Zone 0: 4040/0.88= 4590 W

    Zone 1: 4130/0.88= 4693 W

    SRX5800 DC high-capacity

    86 %

    Zone 0: 4040/0.86= 4697 W

    Zone 1: 4130/0.86= 4802 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 Services Gateway with SCB2 and RE2

    Power Supply

    Thermal Output (BTUs per hour)

    SRX5800 AC high-capacity

    (4590 + 4693) * 3.41 = 31,655 BTU/hr

    SRX5800 DC high-capacity

    (4697 + 4802) * 3.41 = 32,452 BTU/hr

Sample configuration for SRX5800 Services Gateway 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 one Routing Engine installed in SCB 0

  • IOC3 (SRX5K-MPC3-40G10G or 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 services gateway in order to install and use SPC2. If you do not have high-capacity power supplies and fan trays installed, the services gateway will log an alarm condition when it recognizes the SPC.

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

    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 10.

    Table 10: Sample Power Requirements for an SRX5800 Services Gateway 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 4

    SPC2

    See note below.

    585 W * 5= 2925 W

     

    2925 W

    MPC - slot 5

    IOC3

    607 W

     

    607 W

    SCB 0 (slot 6 for Zone 1)

    SCB3 with RE2

    300 W

    90 W

    390 W

    SCB 1 (slot 7 for Zone 0)

    SCB3

    300 W

    300 W

    MPC - slot 8

    IOC3

    607 W

    607 W

    SPC - slots 9 through 13

    SPC2

    See note below.

    585 W * 5 = 2925 W

    2925 W

    Total power requirement

    SRX5800 standard-capacity AC (not zoned) 8444 W

    Zone 0 total: 4177 W

    Zone 1 total: 4267 W

    For the power consumption specifications of specific SRX5800 services gateway cards, see the SRX5400, SRX5600, and SRX5800 Services Gateway 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 11 lists the power supplies, their maximum output power, and unused power (or a power deficit).

    Table 11: Calculating Power Budget for SRX5800 Services Gateway with SCB3, IOC3,and RE2

    Power Supply

    Maximum Output Power of Power Supply

    Maximum Output Power for System

    Nonzoned Unused Power

    Zone 0 Unused Power1

    Zone 1 Unused Power2

    SRX5800 AC standard-capacity

    1700 W

    5100 W

    Power exceeded (non-zoned; 5100 W - 8444 W = -3344 W power exceeded)

    SRX5800 AC high-capacity

    1700 W (one feed)

    4100 W (two feeds)

    3400 W (one feed)

    8200 W (two feeds)

    Power exceeded

    4100-4177=-77 W

    Power exceeded

    4100-4267=-167 W

    Note: Power is exceeded. Therefore, there is not enough power to cover redundancy with this configuration.

    SRX5800 DC normal-capacity

    2800 W

    5600 W

    Power exceeded

    Power exceeded

    SRX5800 DC high-capacity

    1700 W (one feed)

    4100 W (two feeds)

    3400 W (one feed)

    8200 W (two feeds)

    Power exceeded

    4100-4177=-77 W

    Power exceeded

    4100-4267=-167 W

    Note: Power is exceeded. Therefore, there is not enough power to cover redundancy with this configuration.

    1 For this configuration, output power is 4177 W.

    2 For this configuration, output power is 4267 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 12.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 12: Calculating Input Power for SRX5800 Services Gateway with SCB3, IOC3, and RE2

    Power Supply

    Power Supply Efficiency1

    Input Power Requirement

    SRX5800 AC high-capacity

    ~88 %

    Zone 0: 4177/0.88= 4764 W

    Zone 1: 4267/0.88= 4849 W

    SRX5800 DC high-capacity

    86 %

    Zone 0: 4177/0.86= 4857 W

    Zone 1: 4267/0.86= 4962 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 for SRX5800 Services Gateway with SCB3, IOC3, and RE2

    Power Supply

    Thermal Output (BTUs per hour)

    SRX5800 AC high-capacity

    (4764 + 4849) * 3.41 = 32,780 BTU/hr

    SRX5800 DC high-capacity

    (4857 + 4962) * 3.41 = 33,482 BTU/hr

Sample configuration for SRX5800 Services Gateway 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 services gateway in order to install and use SPC2 and SPC3. If you do not have high-capacity power supplies and fan trays installed, the services gateway will log an alarm condition when it recognizes the SPC.

  • High-capacity cooling system (upper and lower 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-IOC4-10G

    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

    For the power consumption specifications of specific SRX5800 services gateway cards, see the SRX5400, SRX5600, and SRX5800 Services Gateway 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 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)

    4100-3635=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 16.

    Table 16: 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 17 .

    Table 17: 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 Services Gateway 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 services gateway in order to install and use SPC2 and SPC3. If you do not have high-capacity power supplies and fan trays installed, the services gateway will log an alarm condition when it recognizes the SPC.

  • High-capacity cooling system (upper and lower 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 18.

    Table 18: 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

    For the power consumption specifications of specific SRX5800 services gateway cards, see the SRX5400, SRX5600, and SRX5800 Services Gateway 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 power output of the available power supply options.

    Table 19 lists the power supplies, their maximum power output, and unused power (or a power deficit).

    Table 19: 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 20.

    Table 20: 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 21 .

    Table 21: 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