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StorageTek SL3000 Systems Assurance Guide E20876-08 |
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# 5 Power and Cooling

There are several power options for the SL3000 library. When selecting the proper power configuration, the customer should consider any power redundancy requirements along with the features and number of drives that will be supported in the library.

All power supplies and power distribution units (PDUs) within the SL3000 library reside in the Base Module (Base) and Drive Expansion Module (DEM).

## Power Configurations

The power configuration for the SL3000 library depends on the AC power source option selected and the power redundancy.

### AC Power Source Options

The SL3000 library has two AC power source options for the Base and DEM. Both are single phase:

- 120 VAC, 50/60 Hz, at 20 amps (range: 100–127 VAC, 47–63 Hz, 16 amps)

  - Limited support for T9840 and T10000 drives; no redundant robotics support.

- 240 VAC, 50/60 Hz, at 30 amps (range: 200–240 VAC, 47–63 Hz, 24 amps)

  - Supports all drive types and redundant robotics.

Each PDU installed in the library requires a separate AC power source. There can be a maximum of four PDUs in the library, depending on the configuration selected.

### Power Redundancy Options

There are three power configurations that offer various levels of power redundancy.

#### N+1 power configuration (standard)

- Offers DC power redundancy only

- Consists of one AC PDU (per Base or DEM), with one extra drive DC supply and one extra robotics DC supply

- Provides N+1 DC power supply redundancy

- Limited support for T9840 and T10000 drives and no redundant TallBot support

#### 2N power configuration

- Offers both AC and DC power redundancy

- Consists of two PDUs (per Base or DEM) for AC redundancy, with a set of DC power supplies for each PDU

- Provides N DC power supplies per PDU

- Requires two separate AC input sources per Base or DEM

- Required for redundant TallBot and redundant electronics support

#### 2N+1 power configuration

- Offers both AC and DC power redundancy with additional DC redundancy

- Consists of two PDUs (per Base or DEM) for AC redundancy, with additional DC power supplies for each PDU

- Provides N+1 DC power redundancy for each PDU, except the second PDU only has N DC power supply redundancy for the TallBot

- Requires two separate AC input sources per Base or DEM

- Supports redundant TallBot and redundant electronics

## DC Power Supplies

The SL3000 library uses two types of DC power supplies:

- Load sharing 1200W DC (used for the robotics unit and tape drives)

- 200W cPCI (used for the electronics control module)

Figure 5-1 Power Supply Locations - Base and DEM (Rear View)

### Robotics Unit Power Supplies

The robotics unit in the SL3000 library uses load sharing 1200 W DC power supplies located at the top of the Base (there are no robotics DC supplies in the DEM) — see Figure 5-1. The 1200 W DC power supply used for the robotics unit is the same power supply used for the tape drives. For ordering information, see "DC Power Supplies".

Each Base ships standard with two robotics DC power supplies used for N+1 and 2N configurations. A third DC power supply is required with the 2N+1 configuration.

### Electronic Control Module Power Supplies

The electronics control module (ECM) uses 200 W cPCI power supplies. These power supplies are located below the HBT card in the Base (there are no ECM power supplies in the DEM) — see Figure 5-1. The power supply for the electronics control module is different from the power supplies used for the robotics unit and the tape drives. Only the 2N+1 configuration requires ordering two additional ECM supplies, for ordering information, see "DC Power Supplies".

Each Base ships standard with two ECM power supplies used for N+1 and 2N+1 configurations. Two additional ECM power supplies are required with the 2N+1 configuration.

### Tape Drive Power Supplies

The tape drives in the SL3000 library use load sharing 1200 W DC power supplies. Up to four tape drive power supplies are located to the left of each PDU in both the Base and the DEM — see Figure 5-1.

The library ships with two tape drive DC power supplies per Base and two tape drive DC power supplies per DEM. The number of tape drive DC power supplies required depends on the power configuration selected and the number and type of tape drives in the library. To calculate the number of power supplies to order, see "Calculating Tape Drive Power Supply Quantities" below.

## Calculating Tape Drive Power Supply Quantities

The number of supplies required, depends on:

- Power configuration (120 VAC or 240 VAC with N+1, 2N, or 2N+1)

- Number and type of tape drive (T10000, T9840, or LTO)

To determine the number of power supplies required in a specific library configuration:

1. Determine the total number of each drive type.

2. Multiply by the watts-per-drive for each drive type, see Table 5-1, "Watts Per Drive".

3. Add together the watts used by each drive type to calculate the total watts consumed.

4. Use Table 5-2 through Table 5-5 to determine the number of DC power supplies needed.

Refer to "DC Power Supplies" for ordering part number information.

### Watt Consumption Per Drive

Table 5-1 Watts Per Drive

Drive Type | Maximum Watts Used by Each Drive
--- | ---
T9840D | 100
T10000A/B/C | 93
T10000D | 127
LTO | 46

### Power Supplies Required for 120 VAC PDUs

To use 120 VAC PDUs, the total watts used by the drives must be less than 843 W in the Base and less than 1,481 W in the DEM. 240 VAC PDUs are required if the total watts exceeds 843 W in the Base or 1,481 W in the DEM.

Table 5-2 DC Power Supplies for Base (120 VAC PDU)

Total Watts Used by All Drives | Power Supplies Required for N+1 | Power Supplies Required for 2N | Power Supplies Required for 2N+1
--- | --- | --- | ---
1 - 563 | 2 | 2 | 4
564-843 | 3 | 4 | 6

Use the following table to calculate the number of power supplies required in the DEM when using a 120 VAC PDU.

Table 5-3 DC Power Supplies for DEM (120 VAC PDU)

Total Watts Used by All Drives | Power Supplies Required for N+1 | Power Supplies Required for 2N | Power Supplies Required for 2N+1
--- | --- | --- | ---
1 - 700 | 2 | 2 | 4
701 - 1,400 | 3 | 4 | 6
1,401-1,481 | 4 | 6 | 8

Note: You cannot mix 120 VAC with 240 VAC PDUs within the library. All PDUs must be the same type.

### Power Supplies Required for 240 VAC PDUs

240 VAC PDUs are required if the total watts used by the drives exceeds 843 W in the Base or 1,481 W in the DEM.

Table 5-4 DC Power Supplies for Base (240 VAC PDU)

Total Watts Used by All Drives | Power Supplies Required for N+1 | Power Supplies Required for 2N | Power Supplies Required for 2N+1
--- | --- | --- | ---
1 - 1,063 | 2 | 2 | 4
1,064 - 2,263 | 3 | 4 | 6
2,264 - 3,463 | 4 | 6 | 8
3,464 - 3,805 | 5 | 8 | 8

Table 5-5 DC Power Supplies for DEM (240 VAC PDU)

Total Watts Used by All Drives | Power Supplies Required for N+1 | Power Supplies Required for 2N | Power Supplies Required for 2N+1
--- | --- | --- | ---
1 - 1,200 | 2 | 2 | 4
1,201 - 2,400 | 3 | 4 | 6
2,401 - 3,600 | 4 | 6 | 8
3,601 - 4,443 | 5 | 8 | 8

Note: You cannot mix 120 VAC with 240 VAC PDUs within the library. All PDUs must be the same type.

### Example: Calculating Required Number of Drive DC Power Supplies

The following example shows how to calculate the DC power supplies required in a mixed media library. The sample library has a Base and a DEM with all three drive types (T10000, T9840, LTO). Table 5-6 shows how to calculate the total watts used by the mixed tape drives in both the Base and DEM:

Table 5-6 Base Module Tape Drive Watts Consumption Example

Drive Type | Quantity of Drives | Multiply by Watts Per Drive | Total Watts Per Drive Type
--- | --- | --- | ---
T10000D | 6 | 127 | 762
T9840D | 6 | 100 | 600
LTO4 | 4 | 46 | 184

The drives in the Base use 1,546 W. In Table 5-2, 1,546 W exceeds the maximum 843 W supported by a 120 VAC PDU. Therefore, the Base requires a 240 VAC PDU to support the drive configuration, so refer to Table 5-4.

Table 5-7 DEM Tape Drive Watts Consumption Example

Drive Type | Quantity of Drives | Multiply by Watts Per Drive | Total Watts Per Drive Type
--- | --- | --- | ---
T10000C | 4 | 93 | 372
T9840D | 2 | 100 | 200
LTO5 | 4 | 46 | 184

The drives in the DEM use 756 W. In Table 5-3 and Table 5-5, either a 120 VAC or 240 VAC PDU can support 756 W. However, you cannot mix 120 VAC with 240 VAC PDUs within the library. Therefore, the example library requires 240 VAC PDUs.

Two tape drive DC power supplies ship standard with the Base and two power supplies ship standard with the DEM. Therefore, subtract two from the DC supplies required. Use Table 5-4 and Table 5-5 to determine what to order.

The tables below list the power supplies required for the example library.

Table 5-8 DC Supplies Required for Base Example

Configuration Option | DC Supplies Required | DC Supplies to Order (= Required - 2)
--- | --- | ---
N+1 (240 VAC PDU) | 3 | 1
2N (240 VAC PDU) | 4 | 2
2N+1 (240 VAC PDU) | 6 | 4

Table 5-9 DC Supplies Required for Drive Expansion Module - Example

Configuration Option | DC Supplies Required | DC Supplies to Order (= Required - 2)
--- | --- | ---
N+1 (240VAC PDU) | 2 | 0
2N (240VAC PDU) | 2 | 0
2N+1 (240VAC PDU) | 4 | 2

The number of drive DC supplies that must be ordered depends on the power configuration selected. For instance, if the example library had a 2N+1 configuration, it would require an order of six additional drive DC power supplies (4 supplies for the Base and 2 supplies for the DEM). The 2N+1 also requires an additional ECM 200W cPCI power supply. The ECM power supply is different than the tape drive and robot power supplies listed in this example. For ordering information, see "DC Power Supplies."

## AC Power Cables

The following table lists the cables required for each power configuration. You must order one power cord per PDU installed:

- N+1: One power cord for the Base and an additional power cord for the DEM (if installed)

- 2N or 2N+1: Two power cords for the Base and two additional power cords for the DEM (if installed)

Table 5-10 Power Cable Descriptions

Power Source | Description | Circuit Breaker | Wall Connector | Library Connector | Power CordLength/Type
--- | --- | --- | --- | --- | ---
120 VAC/20A | US/Japan | 20A | L5-20P | L5-20R | 3.7 m (12 ft) 12 AWG
240 VAC/30A | US | 30A | L6-30P | L6-30R | 3.7 m (12 ft) 12 AWG
240 VAC/30A | International | 30A | 330P6W | L6-30R | 4 m (13 ft) HAR

## Power Consumption

For environmental or economical reasons, you may want to determine the total power consumption (watts), CO2 emission values, and British Thermal Units (Btu/hr) for the SL3000 library and tape drives. The table below provides power consumption in watts.

Table 5-11 Power Consumption Values

Components | Quantity | Idle Watts | Max Watts
--- | --- | --- | ---
Base Library (required) Includes: 1 ECM, 1 robot, and 1 CAP | 1 | 156 | 197
Redundant Electronics (optional) | 1 | 100 | 100
Redundant Robotics (optional) | 1 | 28 | 55
Operator Panel (optional) | 1 | 29 | 37
Additional CAPs (optional) | Each | 10 | 14
Access Expansion Module (optional, 1 or 2) | Each | 8 | 30
T9840 | Each | 79 | 100
T10000A/B/C | Each | 61 | 93
T10000D | Each | 64 | 127
LTO | Each | 30 | 46

### Calculating Total Watts, CO2 Emissions, and Btu/hr

To calculate the total power consumption in Watts for the library, add up all the applicable wattage values for the library configuration from Table 5-11.

To calculate kilograms of CO2 emissions per day, multiply watts by the CO2 emissions constant. Use the constant that is applicable for your country (0.02497 for US).

To convert electrical values to Btu/hr, multiply the number of watts by 3.412 (1 W =3.412 Btu/hr). Many manufacturers publish kW, kVA, and Btus for their equipment. Use the information provided by the manufacturer. Otherwise, use the formula below.

- 3.41214 x Watts =Btu/hr

#### Power Consumption Example 1

Using the maximum continuous values for the following components:

Table 5-12 Power Consumption Example

Quantity | Component Description | Watts
--- | --- | ---
1 | SL3000 Base (including one ECM, one robot, one CAP) | 197
16 | LTO4 Tape Drives | 736
-- | Total | 933

- Emissions: 933W x 0.02497 = 23.3 Kg of CO2

- Power consumption: 933W x 3.412 = 3,183 Btu/hr

#### Power Consumption Example 2

Using the maximum continuous values for the following components:

Table 5-13 Power Consumption Example

Quantity | Component Description | Watts
--- | --- | ---
1 | SL3000 Base (including one ECM, one robot, one CAP) | 197
8 | T9840D Tape Drives | 800
1 | Drive Expansion Module | --
8 | T10000C Tape Drives | 744
1 | Cartridge Expansion Module | --
3 | CAPs (3 at 10 Watts each) | 30
-- | Total | 1,771

- Emissions: 1,771W x 0.02497 = 44.2 Kg of CO2

- Power consumption: 1,771W x 3.412 = 6,043 Btu/hr

## Cooling

Cooling within the SL3000 library is divided into three areas:

- Electronics control module

- Tape drives

- DC power supplies

### Library Electronics Control Module

Two fans, located to the right of the electronics control module, provide cooling for the electronics in the library. Air is drawn from the sides of the library and flows through the fans to the rear of the library.

- The library controller card (HBCR) monitors these fans for proper operation.

- An amber Fault indicator is on the fan assembly to indicate a failure.

While there are two dedicated fans, one fan is sufficient to provide adequate cooling for the library and the electronics. The fans can be replaced without interfering with library operations. Therefore, replace a defective fan when it is detected.

### Tape Drives

Each tape drive tray contains a fan for drive cooling. The tape drive's power converter card supplies power for the fans. Air is drawn from the front of the drive and flows through the fan to the rear of the drive/library.

### DC Power Supplies

Each 1200 Watt DC power supply contains a fan that pulls air from the library, through the rear of the supply, and out the rear of the library.