An intro to commercial electricity and 3 Phase Power

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So, you’re looking for equipment for a new location. Before you buy anything there are a couple of really important electricity related things you’ll want to know/find out:

  • Does the new location have 3 Phase power?
  • What is the amperage supply to the building?

This information will determine what equipment is available to you. If you have the answers before you go shopping it will save you a lot of frustration, wasted time and possibly the expense of having to convert a piece of equipment from three phase to single phase.

What the heck is 3 phase power?

Three phase power is a variation of power that is often used for big equipment. In a three phase system, circuit conductors carry three alternating currents of the same frequency. There is a delay between each of the three currents (phases) which results in a constant power transfer over each cycle of the current.

Benefits of 3 Phase power:

  • Consistency in power delivery
  • Efficiency. Three phase motors draw much less current than the equivalent single phase motor; therefore they will be cheaper to operate.
  • Simplicity in motor design. Three phase systems can produce a magnetic field that rotates in a specified direction, simplifying the design of the motor.

If this isn’t technical enough and you would like some more detailed infomration on 3 phase power, Vin Marshall has a great article :

How do I know if I have Three Phase Power Available?

No residential location has three phase power. It is only available in commercial buildings. Not all commercial buildings are equipped with three phase power. If your specific unit does not have three phase power being used currently, a three phase power supply may still be available in the building. Your Landlord or Realtor should be able to tell you.

To look into this yourself: when you look at your breaker panel there will be three switches tied together. (see picture)

3 phase breaker3 phase breaker


OK, so now you know whether you have single or 3 phase power available, the next step is to find out what the maximum amperage supplied to your building unit is.

What is amperage? Think of it this way; to use the common anology comparing electrical terminology to water in a pipe, amperage is the volume (how big the pipe is) and voltage is the pressure or speed that the water passes through the pipe with. Newer commercial units will have 200-250 amps available to start for a smaller room and go up from there.
Each piece of equipment has an amperage rating. Certain machines, such as steam kettles and ovens (typically things with elements/ heaters) require larger amperage to run. These machines often use 45-50 amps each and they will take up a greater portion of the available amps in comparison to things like mixers, grinders and small appliances.

You need to calculate the amperage load with everything you intend to run and then add 20% to give you the required electrical “headroom”. If in doubt, you should always check with your electrician.

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