Power

Power may not techincally be consider part of “Layer 1” but it is a cirtial and often over look part of IT. Below I will go over the basics of power and then go into how it applies to IT.

Voltage (V)

  • Electromotive Force or often refered to as electric pressure.
  • Common House voltage (in the US) is 120V but many higher end servers and UPS’s run on 240V.

Amps (A)

  • Amps are a measure of the flow of power, ushally you can think the thicker the cable the more AMPs (or electric flow) it can handel. (Again the plumbing )

Watts (W)

  • The unit for Power is Watts, and watt is the combination for Voltage and Amperage. (W=V * A)
  • Power Supplies are desigged to work at certiain voltages and amperage. It is alway important to check the type of power circuits you have and the power supply you are about to order.

Connectors NEMA / IEC “320”

NEAM Power

NEMA (National Electrical Manufacturers Association)
  • [Locking]Voltage-Amperage-Gender
  • Voltages 6 = 240 - 5 = 120
  • Amperage as given 15 = 15 Amps 20 = 20 Amps
  • Gender P = Plug (Male) R = Receptcual (Female)
  • Locking = L Is if there is a twisting formfact to lock the plug in place.
IOS IEU
  • These are the connectors you see plugging into almost all computer, server and networking power supplies.
  • Note the notch veraint used on some equipment
  • This is a very popular version used in the power strips in datacenter.
  • Note this connector type supports both 120V and 240V so if you plug your server in a nothing happens check the votage it needs vs what kind of circit you have.

UPS (Uninterruptable Power Supplies) / Battery Backup

  • UPS and Battery backups serve two main purposes, to provide clean power, and support the power load in the case of a power outage.
  • UPS can be small enough to fit next to your desk or big enough to support data centers and take up several rooms.
  • However most IT professionals with deal with smaller sized. These UPS are measure ing KVA

PoE (Power over Ethernet)

  • Power over ethernet like the name implies, is provding power over an ethernet (CAT5 or above) cable.
  • PoE is widly popular simplifying todays office allowing one ethernet cable to both provide power and data to VoIP phone ans Wireless Access Points, to name afew.
  • PoE is defined by these main standards.

Power Budgeting

PDU (Power Distrobustion Unit)

  • This term means differnt things to different people and different situwations.
  • Technially a PDU is used

Power Strips