3 phase question

[Anonymous]

WG
I am considering installing some low voltage alarm equipment that requires a 110V outlet at a tanning salon. The "handy" owner said he could "throw in" a single pole 20 amp breaker for this. I of course I wont touch the high voltage stuff - But he is bouncing a couple questions off me :( regarding his purposed outlet plan. He has 4 different panels serving this building with large buck boost transformers wired to some. There is one panel that he would like to connect to that has a main disconnect inside at the top with three feeders coming in with no buck boosts wired to it - the panel is a standard 200 amp resid. panel. He has measured 208 between the two main bus bars and 110 between either of the two busses and ground. The panel currently has only three double pole breakers feeding three beds and a single pole 30 amp feeding lights. He wants to run his one circuit from this panel to feed the alarm panel outlet, then continue this circuit to a switch for a single flourecent light. My questions for you: Does this sound ok? Is there anything that he should look for, or avoid while doing this? His plan calls for 1/2 flex and solid 12G wht - blk- and green for ground. Total run is about 50' - Finally, unrelated to this question - My curiosity is peaked regarding the large buck boost transformers over some of these panels. As said - I'm not touching the stuff - just wondering what those big 60lb. honkers do specifically. I have referenced some info over the web regarding these transX being used for tanning beds- I knew you would have the total scoop. Just trying to learn. Thank you!

[imported_joed]

I not an expert. The one thing that I see is #12 is only good for 20 amp. If you need 30 amp then use #10.

[Wgoodrich]

You numbers on your voltages are not matching a normal residential panel. I am suspecting you have a main 3 phase service that is a wye connected power source with 208 between any of the THREE hot wires to that panel. If you have two hot wires then you have a residential panel on a three phase system pulling only two hot legs.

Problem with this is that your equipment will be expecting 120 / 240 volt and it will be receiving from what you are stating 110 / 208 volts. This should be no problem other than increase the load being applied by about 10%. Only thing you need to be concerned about is that your electronic equipment is being fed a voltage within its listed range. You should find that voltage range allowance on your manufacturer's installation instructions. If it says + or - 10% or 110/120 or 208/240 then you are fine with this power source.

What you are calling flex is probably type MC or type AC wiring style often found in commercial buildings this to is fine.

The buck / boost transformers you are seeing in a tanning shop is probably the fact the tanning beds are from a foreign country with manufacturer's instructions that you must feed them with 100 or 200 volts 50 cycle and the power source is 120 / 240 volts 60 cycle. You can buy transformers to buck or boost to the voltage compatible with foriegn products including changing the cycling if need be. I suspect this is what is happening in that shop.

Wolf tanning beds are often as I discribed above.

Hope this helps

Wg