In this section:
Power enters the DSC 8000 chassis through the DC Power Entry Module (PEM). The DC PEM is rated for a voltage range of -43.5 to -60 VDC. There is only one (1) DC PEM per chassis. The power capacity of the system is dependent on the specific model and the number of Power Modules (PMs) used in the chassis. The hot-swap DC PMs are each rated for 1,100 W per unit.
Note
The YSD.00124 Rectifier is available as a specific order from Ribbon if you prefer to use AC power for your system. The Ribbon part number for this equipment is 200Q059710. The Field Installation Guide is included with your order. If you require more information about this power system and how to order the system, contact Ribbon Sales.
Power Distribution
The following figure, DSC 8000 Power Channels, illustrates the MicroTCA power distribution. The horizontal lines represent connections between the slots. The DSC 8000 has a star-topology power channel interconnect backplane. Power channel switching is provided on every PM allowing any PM to be assigned to provide power to any payload slot. The DSC 8000 defines 16 power channels: 2 MCHs, 2 cooling units (CUs), and 12 AMCs.
While each PM can power any payload channel in the system, there is only one PM assigned as a primary supply to each payload. Each channel assignment controls both the Management Power (MP = 3.3 V) and Payload Power (PP = 12 V) as a pair.
The following figure shows that the MCH channels have two interconnects for PP, while all other payloads have only one interconnect for PP.
DSC 8000 Power Channels
The following figure shows the power distribution within a shelf.
Power Distribution for a Chassis
Note
The above figure shows power interconnects to four PM slots on a DSC 8000 chassis; however, only three slots are populated with PMs. To provide N+1 redundancy, the slot designated PM 4 is configured as a backup to provide power to any channel in the event a primary channel fails. Slot PM 3 is not used.
The DSC 8000 chassis contains three Power Modules; two are designated as primary PMs populated in slots PM 1 and PM 2. The third PM is designated as a backup Power Module and is populated in slot PM 4. In the event of a primary power fault, the redundant PM delivers current without interruption.
The modular N+1 redundant power supply configuration is critical in Central Office locations where two power plants deliver redundant DC input to high availability devices.
Power Entry Modules and Power Module Cards
The Power Entry Modules (PEMs) provide power cable entry, Electro-Magnetic Compatibility (EMC) power conditioning, and distribution to the Power Module (PM) slots. Each PM then provides voltage conversion and power channel distribution to the payloads.
There is one PEM and up to three PMs per DSC 8000 shelf.
DC PEM
The DC PEM distributes two feeds to each PM; designated A and B. These dual, isolated feeds are the common method for redundant power entry in the telecommunications environment. For redundancy, each path is capable of supplying the total current for a fully loaded DSC 8000. The PMs employ diodes to inhibit any reverse current flow when both A and B inlet feeds are connected; feed A cannot source power to B and vice versa.
DC Power Modules
DC PMs convert the incoming -48 V / -60 V feed(s) to the appropriate voltages for the DSC 8000 payloads.
The DC-DC conversion is implemented with a fully digital, high efficiency, PM bus managed controller. This controller includes digital voltage adjustment plus digital monitoring of temperature, current, and voltage on the PM.
Each PM employs distribution switching so that each payload can be supplied by any PM in the system. This switching uses digital controls and monitoring by the Enhanced Module Management Controller (EMMC). The switch controllers provide a comprehensive solution for system management such as adjustable current limits and voltage monitors for each channel. Fault conditions are immediately isolated by hardwired controls and then alerts are forwarded by communication to the EMMC layer. Fuses are employed at the input to the DC-DC converters for safety, but these are not serviceable.
Supported Power Features
The sections describe the power features available on the DSC 8000.
Power Channels
Channeling of the 3.3 V (management) and 12 V (bulk payload) power to each load is paired together so that an assigned payload receives both voltages from the same PM channel. This method conforms to the MicroTCA standard and insures that each load is properly managed during payload assignment and fault containment.
Payload Assignments
The DSC 8000 follows the MicroTCA standard for star power distribution. The system configures itself by assigning each payload channel to a specific PM. However, during initial power up, before the intelligent management process is started, one PM is elected to operate in autonomous mode. This start-up PM then automatically provides power to the cooling units and the MCH cards.
The MicroTCA Carrier Management Controller (MCMC) learns of the payload population from a PM because each PM receives the card slot presence signals. The MCMC also learns the quantity of PM cards and performs the accounting task of assigning payload channels to the available PMs. The system assigns payloads to the available PMs in slots 1 and 2 in an alternating fashion up to the capacity of each PM. All channels on PM4 are reserved for redundancy.
160 Watt Extended Power Capability
The DSC 8000 is designed with Ribbon’s Extended Power capability that doubles the standard MicroTCA 80 Watt allowance for each payload slot. In the backplane, each AMC slot position includes a custom connector that extends each power path allowance to 160 W total when the payload power is switched on to that AMC slot.
Redundancy
The DSC 8000 can be configured with redundant Power Modules in an N+1 arrangement; this requires a minimum of two PM cards. PM slot 4 is designated as the redundant supply. Slots PM 1 and PM 2 are the primary Power Modules. In the event of a primary power fault, the redundant PM in slot PM 4 delivers current without interruption. A Power Module is not populated in slot PM 3.
Fault Detection
The PM provides comprehensive fault recognition and fault isolation. For example, each power channel has a current limit threshold on the management power and the payload power (3.3 V and 12 V respectively). The values for the current limit thresholds for each power channel are adjusted to the IPMI advertised needs of each payload module. In a case where the limit is exceeded, the power channel is immediately disconnected. Likewise, the voltage values also have a level threshold for every channel in use. This automated fault detection provides isolation of malfunctions to ensure a high availability system.
Power Budget Planning
To budget power, the system planner should survey each payload including the MCH card(s) and cooling units. Each payload provides a declaration for maximum power demand through the FRU record. An example of one such survey is shown in the following table.
To ensure an adequate power supply, the system is populated with the appropriate number of PM cards to meet the demand. In simplest terms, this means that the total capacity of the PM card(s) must meet or exceed the payload population. Another consideration is with the MicroTCA process that partitions power channels for individual payloads. The system planner must consider the granularity of the PM capacity to resolve payload demand.
Note
For system fault tolerance there must also be a redundant PM installed. PM 4 is not included in the calculation for PM capacity.
The MCMC automatically assigns payloads to the PM population in a round robin fashion. The MCMC performs this assignment using the FRU values from each payload and the FRU advertisement capacity of each PM. Some power margin is necessary to ensure that the PM assignments do not bottleneck from the step function of payloads.
Payload Demand Example
Payload Type | Power (Watts) | Quantity | Aggregate (Watts) |
|---|---|---|---|
| Cooling Units (medium speed) | 110 | 2 | 220 |
| MCH: AMC670-12541 | 79 | 2 | 158 |
| Management or Routing CPU + µRTM | 80 | 12 | 960 |
| Total | = | 1,638 | |
Power Connections
On site power connections have to be made between
- the shelves and the PDU
- the facility power and the PDU
For more information about the PDU, see Power Distribution UnitPower Distribution Unit.
The following figure shows a typical connection diagram between the DSC 8000 shelves, PDU, and the grounding bar.
For detailed cable and hardware information, refer to Grounding the DSC 8000 and Providing Power to the DSC 8000.
TDSC 8000 Power Connection Diagram
Power Distribution Unit
The DSC 8000 is DC-powered. The Power Distribution Unit (PDU) is a Dual 200A 4/5 TPA/GMT fuse panel, located at the top of the 19” rack (see DSC 8000 Control Shelf (Front View)). The PDU provides high-current and low-current fuse protection for the DSC 8000.
The design of the PDU ensures redundancy in case of any problem with supplying power to the system. There are two electrically isolated sides, the “A” side and the “B” side. Each side includes its own high-power inputs, high- and low-current fuses, and high- and low-power outputs.
PDU Fuses
The PDU fuses are not installed at the time of delivery, but are included in the accessory box shipped with the system. The following fuse types are included:
- two TPA fuses for each shelf, one for A feed and one for B feed and a spare (48 V, 50 A rated fuse, Ribbon Part Number 650Q003810)
- three GMT fuses for alarm panel (0.75 A, 60 VDC per each fuse, Ribbon Part Number 650Q003210)
Only install the number of fuses that are required for the DSC 8000. Therefore, if your system is equipped with one chassis in a shelf, install one TPA fuse into location A1 and B1 on the PDU. If your system is equipped with two chassis in the rack, install one TPA fuse into location A1 and B1 and location A2 and B2 and so on.
The following figure shows the mapping of the TPA fuses to the Power Module on each shelf.
Mapping of TPA and GMT Fuses to Power Modules and Alarm Panel, Respectively
Caution
When replacing a TPA or GMT fuse (refer to Replace TPA and GMT Fuses in the PDU), make sure the replacement fuse is the correct fuse type and current rating. Otherwise, an incorrect fuse can cause damage to the protected equipment or the PDU.
The alarm panel requires GMT fuses populated in the PDU for power. For more information about the alarm panel, refer to the topic Alarm Panel.
PDU Cables
The -48 VDC power cable connected between the PDU and Alarm panel is installed before shipment.
Power Consumption
The maximum power consumption for the DSC 8000 is 1,638 W per shelf. Depending on your configuration, each shelf in a multi-shelf configuration consumes different levels of power, up to the maximum power capacity limit of 2,200 W.
To properly budget for power consumption on the DSC 8000, many factors need to be considered for each shelf and are outlined in the following sections.
Note
The actual power consumption is determined by the individual shelf configuration.
Redundant Power Modules and Power Feeds
Each DSC 8000 shelf receives input power from redundant DC power feeds. Each redundant power feed provides input power to all the power modules in the shelf.
DSC 8000 System Cards and Fan Trays
The DSC 8000 system cards and fan trays draw power from the Power Modules. Ensure all installed system cards and fan trays are taken into consideration when calculating system power budget.
Cooling Capacity
Each shelf in the DSC 8000 is designed to cool in excess of the 2,200 W maximum power consumption rating (refer to the topic Cooling Architecture).
Power Budget Example for a Fully Loaded DSC 8000 Chassis
The following table is an example of a power budget provided for your information. µRTM modules are not included because they receive power from their front cards rather than the backplane.
Power Budget for a Fully Loaded DSC 8000 Chassis (Example)
| Component | Units | Watts per Unit | Aggregate (Watts) |
|---|---|---|---|
| PT-MTC5165 and PT_MTC5166 (Fan Trays) | 2 | 110 | 220 |
| AMC671 | 2 | 79 | 158 |
| AMC124 | 8 | 80 | 640 |
| ACM348 | 4 | 20 | 80 |
| Total Power | 1,098 | ||
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