Server Rack Power
Review hot insertion, fault clearing, ORing, busbar drop, and service conditions at rack and shelf boundaries.
Server Rack Distribution and Power-Path Protection
Rack and shelf distribution carries high current through busbars, cables, connectors, input protection, and monitoring. The design must handle normal load, connection and removal, source handover, and fault events without exceeding device, contact, or thermal limits.
Hot-swap control, eFuse protection, and ORing serve related but different roles. A hot-swap path controls connection and inrush; ORing manages current flow between sources; a fuse or breaker provides a defined interruption function. Confirm which behavior each device actually provides in the system.
Evaluate the full path from power shelf to tray, including pass-device SOA during startup or faults, connector and busbar resistance, current sharing, sensing accuracy, and the cooling available at the installation point.
Component Requirements
Typical functions, devices, and parameters in Server Rack Power.
| System function | Typical devices | Key parameters | Browse |
|---|---|---|---|
| Shelf and rack interconnect Carries current from the power shelf through busbars, cables, and mating connectors to IT equipment. | Busbar connectors, cable assemblies, terminals, current sensors | Current, voltage drop, contact resistance, temperature rise, mating | View category |
| Hot-swap and eFuse path Controls connection, inrush, overload, and interruption at shelf or board inputs. | Hot-swap controllers, eFuses, MOSFETs, current-sense resistors | Inrush, power limit, timer, fault energy, MOSFET SOA | View category |
| ORing and source selection Manages current between redundant feeds and limits reverse flow where required. | Ideal-diode controllers, ORing FETs, source supervisors | Reverse current, forward drop, handover, sharing | View category |
| Rack monitoring Reports current, voltage, and temperature at distribution points for system supervision. | Current monitors, ADCs, temperature sensors, management MCUs | Measurement accuracy, bandwidth, interface, fault reporting | View category |
Design & Selection Considerations
Insertion and fault events
Define bus voltage, output capacitance, load startup, hot-short, fault current, limit level, and the required interruption behavior.
Pass-FET operating area
Check the device SOA for the voltage/current overlap and duration during startup, overload, and short circuit at the relevant temperature.
Redundant source behavior
Specify output sharing, reverse-current blocking, handover timing, and failure response for each power shelf or feed.
Connector and busbar heating
Assess current distribution, contact and conductor resistance, derating, insertion cycles, and cooling at the installed location.
Supply Chain Considerations
Protection request needs the event profile
Include output capacitance, source impedance, fault current, event duration, and controller timer or power-limit settings when reviewing a hot-swap path.
ORing must match redundancy topology
Provide the number and arrangement of feeds, source voltages, sharing method, and reverse-current requirement before comparing devices.
Interconnect depends on installation
Record the exact connector, busbar, mounting, airflow, service cycle, and temperature-rise limits for the intended rack.
Supply Chain Support
Power-path BOM
List shelf outputs, busbar and connector families, hot-swap and ORing controllers, pass devices, current sensors, and monitors.
System constraints
Provide fault and inrush data, source redundancy, mechanical interface, thermal conditions, and required maintenance procedure.
Frequently Asked Questions
During inrush or a fault, the pass MOSFET may carry current while sustaining a substantial voltage drop. Check its safe operating area for the event duration and temperature, along with controller power limiting, timer, and the connected capacitance.
Hot-swap control manages connection to a live bus and can limit inrush or fault current. ORing controls the path between redundant supplies and may block reverse current. Some designs combine functions, but the selected controller and external devices must be checked for each required behavior.