Using a 3-phase generator for 1-phase load

[KenRad]

I have a 3-phase 208 volt emergency generator that I want to use for single phase loads. Is there any problem with running the generator for prolonged periods while only using two of the three legs?

---KenRad

 

[wareagle]

Why not install a 120/208 3 phase panel and balance your single phase load on all phases?

 

[davidbeach]

If you have access to both ends of all three windings you can connect them so that you get 120/240 single phase using all three windings. /\._ Each line is one winding, the dot is the neutral.

 

[busbar]

wareagle has the best suggestion—it permits full-capacity-genset loading. If no 120V loads are served, you could also jack that puppy's AVR up to 139V/coil and get 240V ø-ø times three.

For connecting “edison 3-wire” service to a 12-lead stator, see page 6+ of www.marathonelectric.com/generators/BROCHURE/GPN016.pdf   In all three cases reduce available power to two-thirds of nameplate.

• DOUBLE-DELTA—SINGLE-PHASE CONNECTION  Most typical arrangement.

• LOW ZIG-ZAG—SINGLE-PHASE CONNECTION  {Also termed “Le Blanc”} Less voltage balance with respect to neutral, and the fun of making two sets of 4+ wire pigtail wads.

• HIGH-VOLTAGE—SERIES-DELTA CONNECTION   {Abandon/tape off “L1” external connection} Fine for 120/240V 3-wire if full neutral current is not needed {<50%.} Makes easier pigtail bolting/taping.