208Y backup generator for 240 high leg

[hillbilly1]

You get pretty much no support from Generac that isn't in end users manuals unless you are an authorized distributor/service provider

We were at one time, and still didn’t get any support!

 

[motormuff]

I'm getting ready to install a new backup generator for a small sewage pump station. The service is 240V high-leg delta, and the generator that is already set is 208Y. What should I look out for when wiring this setup? The main load is a couple of pumps, but there are also some lights, receptacles, etc. I'm assuming the generator supplier did account for higher amps at 208. I did confirm the ATS is a switched neutral.
TIA

I'm getting ready to install a new backup generator for a small sewage pump station. The service is 240V high-leg delta, and the generator that is already set is 208Y. What should I look out for when wiring this setup? The main load is a couple of pumps, but there are also some lights, receptacles, etc. I'm assuming the generator supplier did account for higher amps at 208. I did confirm the ATS is a switched neutral.
TIA

I don't see any reason why you can't make this work. The transfer switch must be open transition so a total disconnection of the utility will occur when the the transfer switch changes position to the generator. Transfer switch would be programed with transfer points and generator stop/start operation. I am guessing your current transfer switch is open transition since closed transition is more money. SO you WILL have a momentary loss of power while transferring. If you want a bump less transfer you will need a different generator. Your single phase loads will come from the existing panel. Check with your AHJ and iron out any flaws in this theory. Though not ideal, your 230 volt 3 phase motors will run fine on 208V. Life may be shortened but have seen many 230 volt motors run many years on 208. Does the NEC allow a change in supply voltage, open delta to wye transformer supply? I don't know as I have never researched.

 

[norcal]

Since the OP;s "problem" has been solved and in accordance with electrofelon;s post #32 meeting the number of required posts I will take the liberty of relating a "nameplate" incident
One of the jurisdictions where I inspected, at that time, would accept a PE's stamped information in lieu of a NRTL certification.
This particular PE wanted some guidance as to what was required and was shown a sister installation of the equipment which was UL certified.
He took down all the nameplate data and submitted his letter along with having a corresponding nameplate placed on the new equipment.
The two nameplates were identical...only problem being the UL unit was 480, the "engineered"one was 208.
Sometimes nameplates cant be trusted

Someone told me a story about a gen installation at a 911 center, got it installed & went to test it, as soon as it transferred, everything went black, turns out neither the job foreman, or the engineer bothered to check the nameplate, the building was 208/120V, & the gen was 480/277V, heard heads rolled on that one as they should.

 

[kwired]

Someone told me a story about a gen installation at a 911 center, got it installed & went to test it, as soon as it transferred, everything went black, turns out neither the job foreman, or the engineer bothered to check the nameplate, the building was 208/120V, & the gen was 480/277V, heard heads rolled on that one as they should.

They should have run the generator in manual mode (no transfer) and checked voltage and phasing just in case something was wrong anyway.

I did this with a smaller single phase Generac one time and did find voltage was well below what it should have been. Ended up voltage regulation settings were not set right.

 

[ptonsparky]

Why anyone would not check voltage before connecting loads is beyond me. Heads should have rolled.

 

[Electromatic]

I'm still waiting for the generator supplier/CAT to commission the genset. I hope they did re-strap it like they said.

On another note at this same site: I came to find out that the high leg was never moved from the C phase at the meter to the B phase in the service disconnect or anywhere downstream. The C phase is the high leg throughout. On top of that, the panel was actually designed for a high leg, with the top few slots bussed as 3-phase and the rest of the breaker spaces bussed A, C --- great if the high leg is B-phase as it should be, but instead, every other breaker space on the lower half of the panel is 208. What a clusterfudge!!

 

[hillbilly1]

I'm still waiting for the generator supplier/CAT to commission the genset. I hope they did re-strap it like they said.

On another note at this same site: I came to find out that the high leg was never moved from the C phase at the meter to the B phase in the service disconnect or anywhere downstream. The C phase is the high leg throughout. On top of that, the panel was actually designed for a high leg, with the top few slots bussed as 3-phase and the rest of the breaker spaces bussed A, C --- great if the high leg is B-phase as it should be, but instead, every other breaker space on the lower half of the panel is 208. What a clusterfudge!!

Pretty common around here, because the local electricians don’t know three phase, let alone delta systems. The ones that do, are usually linemen doing side work, and don’t know code.