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Thread: Outfitting new shop but only have 208v service

  1. #1

    Outfitting new shop but only have 208v service

    Hello all. We are outfitting an existing shop with a new planer,jointer,drill press, lathe, spindle sander, edge sander, and Festool for the smaller work. I originally wanted to go all Powermatic but I’m told by our building manager that we only have 208v service. We currently have a few older jointers and a large delta drill press that appear to be 220 rated and they are working fine. My question is, can someone recommend tools that will work well on 208 v service? I found a Bailiegh 208 planer but can’t find reviews. Any help is appreciated

  2. #2
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    208 to me means 3-phase. You might recheck with the building manager. If the service is indeed 3-phase, you have a whole world of machines available.

    If you want to run machines intended for 230 volt single phase, and you have only 208 service, you can use a buck-boost transformer. Correctly connected, it can make 230 from 208.

  3. #3
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    My guess is there is 240 3 phase (somewhere in the building) and they are getting 208 single phase from line to line, it will also give you 120v line to neutral.
    Of all the laws Brandolini's may be the most universally true.

    Deep thought for the day:

    Your bandsaw weighs more when you leave the spring compressed instead of relieving the tension.

  4. #4
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    208 three phase has each of the legs measuring 120v to ground, versus 240 three phase which has one leg that measures 208 to ground. That is usually referred to as delta or high leg system. Motors can be ordered to handle either 208 or 240 or both. It shouldn't be an issue although most 208 service was in a commercial/ industrial area running industrial machinery. It was supplied by a utility and each leg could also supply 110v for lights. Industrial machines will have 208 as a motor choice while lighter duty stuff is generally 240 delta as that is what rpc convert 240 single phase to. You can also boost 208 to 240 with a transformer for a reasonable cost. Dave

  5. #5
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    To make more mud out of clear water I was talking about a 3phase Wye system and Dave a 3phase Delta system.

    In a 3ph Wye you have a nominal 208v line to line and a 120v line to neutral. You get 208v 1ph from two ungrounded hots or 120v 1ph from anyone of the ungrounded lines to neutral.

    From the 240v 3ph Delta system with a secondary center tap you can get 240, 208 or 120v single phase.
    Of all the laws Brandolini's may be the most universally true.

    Deep thought for the day:

    Your bandsaw weighs more when you leave the spring compressed instead of relieving the tension.

  6. #6
    You are with in 10% of the 220 voltage and that is considered more than acceptable acceptable.

  7. #7
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    Many people don't know the differences in voltage from different types of power sources. To really know what it is, a volt meter check is the way to go, but 208 implies 3 phase with a neutral providing 120 from any phase to neutral. To know for sure, check the voltage phase to phase all three ways and then check phase to neutral from each phase. There will be differences in the readings, but all should be within a few volts. A three phase delta system will have 240 volts phase to phase. You should avoid taking measurements from phase to ground. Use neutral instead of ground, if one is available, since readings to ground can provide all kinds of errors in your readings. Some three phase delta systems have no neutral at all, some have a neutral, but the readings from each phase to neutral can be very different is it's a high leg or split phase delta system. If you aren't comfortable taking these measurements, have someone with electrical power experience do the measuring and tell you what kind of system that you have.

    In the USA all of these systems can exist, sometimes within the same facility. A 10% variation between the nominal and actual voltage readings is common. Most machinery and motors will work fine if the voltage reading is within 10% of the machine requirement, but buck-boost transformers can be added to slightly raise or lower the voltage if the equipment does not work well on the power supplied. One buck-boost transformer is needed if the power is single phase, three are required if the power is 3 phase Wye connected with neutral, and two or three will be required, depending on the kind of delta power system.

    We also don't have 110 / 220 volt 60 Hz single phase power systems in the USA. The power companies have moved away from that standard to 120 - 240 volt split phase systems many years ago (common household power). It is actually single phase, but center tapped to provide neutral, which is then grounded at the entry point into the building, plus two hot legs which provide 120 volts to neutral and 240 volts between them.

    Charley

  8. #8
    Thanks all! I was pretty sure that we could get away without a complete upgrade, I’m hoping this is the case as that money can go towards more tools,

  9. #9
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    Jason, as noted, you'll probably be just fine. I will bring up the buck/boost thing again merely to say that some Euro type gear is more sensitive to low-voltage and the transformer is the way to deal with that if you do have issues. I had to put one on my slider when the line voltage from the street was dipping a little too far a few years ago and shutting down my saw intermittently. The utility refused to replace the transformer at that point, so I had to deal with it at my end.
    --

    The most expensive tool is the one you buy "cheaply" and often...

  10. #10
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    Be careful of the 10% margin. Yes a 230V motor will operate on +-10% of 230V so 207-253V. Therefore 208V is perfectly acceptable, except that the utility promises 208V +-10% so your building voltage can vary 188-228V. Running undervoltage often results in start capacitor failure. Especially for high load start applications like air compressors and high mass loads a buck-boost transformer is heartily recommended.
    Chuck

  11. #11
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    Quote Originally Posted by Chuck Saunders View Post
    Be careful of the 10% margin. Yes a 230V motor will operate on +-10% of 230V so 207-253V. Therefore 208V is perfectly acceptable, except that the utility promises 208V +-10% so your building voltage can vary 188-228V. Running undervoltage often results in start capacitor failure. Especially for high load start applications like air compressors and high mass loads a buck-boost transformer is heartily recommended.
    Chuck
    All of my woodworking motors are 240v, not 230v. This summer the utility was giving us 206v and I sure didn't do any woodworking. Fortunately my A/C is 230v.

  12. #12
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    It might help if we knew what country you live in. Ex iron curtain countries may have some oddball stuff. USA went to 120/240 around 1920.
    I remember seeing labels on electric clocks "not for use in Chicago". I think they used a different frequency.
    Bill D

  13. #13
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    208Y/120 is likely THE most common supply to small commercial buildings in the US. It is well suited to lots of 120v loads because you have 120v to Neutral from all three phases. Then you still have 208v 3 phase for running large AC systems. You also have 208v single phase available. Problems start if you have motors that need 240v supply to operate.

    This has nothing to do with the US standardizing on 120/240v supply for residential.

    The 208v "hot leg" to neutral from one phase is for 240v 3 phase Delta, which is a different supply than 208Y/120. You are NOT supposed to power anything from that connection. If you look at a load center, you will not find any single breakers on every third slot. That slot will be #3, #6, etc. on older installs and #2, #5, etc. on newer installs. This system works better for light industrial where you are likely to need lots of 240v single phase and less 120v circuits since only one of the phase to phase circuits support 120v to Neutral.
    Last edited by Greg R Bradley; 11-23-2018 at 1:04 PM.

  14. #14
    Having 208V does not always mean 3Ø is available to a tenant, if the building load is sufficient then 208Y/120V 3Ø is brought to the meter stack(s), then single phase 5* jaw meter sockets are connected to balance between phases, this is very common in larger multi-family dwellings also,called 208V network metering.

    *The fifth jaw is installed in either the 6 or 9 O'clock positions & is connected to the neutral.

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