TN102 - Data Center Power
| 102.1 | Summary |
| 102.2 | Typical Connectors |
| 102.3 | Three Phase Power |
| 102.4 | Strain Relief for Vertical Hanging Cables |
| 102.5 | Load |
| 102.6 | Power Quality/Grounding |
| 102.7 | Rack Mount Power Control/Distribution |
102.1 Summary
Various specifications and sources for power distribution in the data center.
102.2 Typical Connectors
NEMA standards prevents plug/outlet
interchange between current or voltage ratings. The
IEC 60320 standard (formerly called 320)
defines the international power connectors typically used for computer
equipment.
Locking blade (twist-lock) power plugs are normally used to connect power to computer racks. The locking blades also prevent accidental disconnection.
| Type | Plug | Receptacle |
|---|---|---|
| IEC 60320 C13/14 120/240 volt, Single Phase 3 wire, grounding 10 amp |
 C14 |
 C13 |
| IEC 60320 C19/20 120/240 volt, Single Phase 3 wire, grounding 16 amp |
 C20 |
 C19 |
| NEMA 5-15 120 volt, Single Phase 3 wire, grounding 15 amp |
 |
 |
| NEMA L5-20 120 volt, Single Phase 3 wire, grounding 20 amp |
 |
 |
| NEMA L6-20 240 volt, Two Pole 3 wire, grounding 20 amp |
 |
 |
| NEMA L6-30 240 volt, two pole 3 wire, grounding 30 amp |
 |
 |
| NEMA L15-20 240 volt, 3Ø, three pole, 4 wire, grounding 30 amp |
 |
 |
| NEMA L15-30 240 volt, 3Ø, three pole, 4 wire, grounding 30 amp |
 |
 |
| NEMA L21-20 120/208 volt, 3ØY, four pole, 5 wire, grounding 20 amp |
 |
 |
| NEMA L21-30 120/208 volt, 3ØY, four pole, 5 wire, grounding 30 amp |
 |
 |
G - Ground, W - Neutral,
X,Y,Z - Service Poles
102.3 Three Phase Power
For North Amercia data centers, three phase power is typicaly either 240 volt delta or 208Y/120 volt wye.
| 208Y/120 volt Wye (four pole) |
 |
| 240 volt Delta (three pole) |
 |
102.4 Strain Relief for Vertical Hanging Cables
|
Cable Grips |
 |
102.5 Load
It is often difficult to know if a given rack overloaded. Traditional clamp
meters require access to single conductor. Load can be measured in multi-core
cables using the
Megger Flexiclamp 200 from
AVO International.
102.6 Power Quality/Grounding
An excellent tutorial on power quality: Power Quality Primer.
The LEM GEO MODEL 15: Ground Resistance Tester from
LEM Instruments can measure
ground quality without disconnecting the circuit. They also have a tutorial
on grounding:
Ground Resistance Principles, Testing, Techniques & Applications
102.7 Rack Mount Power Control/Distribution
- 1U, 6 NEMA 5-15R outlets oriented for transformers Wiremold J60B2B-90.
- 72" vertical, 24 NEMA 5-15R outlets Wiremold UL2065BC.
- 1U, IEC 320 C14 inlet, and 8 IEC 320 C13 outlets Hammond 1582E.
- 2U, 2 power feeds, and 24 IEC 320 C13 outlets Techniques International PT620.
- 1U, IEC 320 C20 inlet, and 12 IEC 320 C13 switched outlets Pulizzi TPC2364.
- 2U, 3 phase feed, and 12 IEC 320 C13 switched outlets Pulizzi PC301/MTD.
- IEC 320 power cords Quail, Electri-Cord
- IEC 320 line mounted plugs and receptacles International Configurations