Three-phase distribution, remote power panels and busway
Trace the data hall power chain from switchgear to rack PDU, understand wye and delta systems and the voltage an outlet actually supplies, read branch and line currents on three-phase PDUs, balance loads, and know which RPP and busway tasks belong to qualified electrical workers.
- Level
- Intermediate
- Length
- About 55 minutes
- Contents
- 3 lessons · 1 video · final exam
- Status
- Published · updated 3 Oct 2026
Skills you'll practise
- Trace the power chain from switchgear through UPS, room PDU and RPP or busway to the rack PDU, and name each item's job
- Work out line-to-line and line-to-neutral voltages and say which voltage a labeled outlet supplies
- Relate branch currents to line currents on a three-phase PDU and choose outlets that keep phases balanced
- Separate tasks a technician may do from those reserved for qualified electrical workers, including busway plug-in units
Course outline
- 1.Three-phase power, RPPs and buswayVideo · 2 min
- 2.From switchgear to the rackLesson · 18 min
- 3.Wye, delta and the voltage at the outletLesson · 19 min
- 4.Balancing load and staying in your laneLesson · 18 min
- 5.Three-phase distribution, remote power panels and busway: knowledge checkKnowledge check · 20 questions
- 6.Three-phase distribution, remote power panels and busway: practical exerciseKnowledge check · 1 question
- 7.UPS module maintenance: the pre-check that failsScenario
- 8.Final exam8 questions · passing it completes the course, so people who already know the material can test out
Sources it draws on
The lessons and questions are written from these references, so learners can go back to the original.
- ASHRAE TC 9.9: Data Center Power Equipment Thermal Guidelines and Best Practices (2016), incl. the 2015 thermal guideline table and notes, power distribution chain, RPPs and busways
- U.S. DOE Federal Energy Management Program: Best Practices Guide for Energy-Efficient Data Center Design (2024), incl. ASHRAE 2021 thermal guideline table, cooling, electrical and metrics sections
- Three-phase electric power: line-to-line and line-to-neutral voltage, star (wye) and delta, neutral current and harmonics (Wikipedia, citing IEC 60050 and IEC 60038)
- Server Technology application note PDU-001: line and branch current limitations of rack PDUs (single- and three-phase, wye and delta)
- Server Technology: three-phase rack PDU solutions (load balancing across phases)
- Starline (Legrand): Track Busway overview (plug-in units with breakers, outlets and metering; adding circuits on an energized busway)
- Starline (Legrand): remote plug-in actuator (engaging plug-in units from outside the incident energy area)
- OSHA 29 CFR 1910.333: Selection and use of work practices (deenergizing, lockout/tagout, qualified persons)
See it with your own jobs and topics
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