208Y backup generator for 240 high leg

[Birken Vogt]

It is very likely the generator can be reconnected for 120/240 delta. But there are a lot of boxes to check when doing that professionally. But it is far preferable to do it this way.

You might also consider splitting the difference if you are forced to remain wye, 125/216, or 127/220 volt, hopefully the small loads can lived with an increased voltage while the large loads have a less-reduced voltage to work with.

As others have stated, the transfer switch motor might want to be double checked. But the logic can probably be adjusted no problem.

 

[ActionDave]

There's a good chance if you look at the nameplate on the motors it will say usable at 208V.

I think it will work. My fair city bought a portable generator for back-up on some of their lift stations that were not outfitted with permanent generators to comply with a state mandated requirement. The generator was 208V. Some of the stations were 240V both open and closed delta and some were 208V. We tested all the stations with the generator and they all ran fine.

 

[Birken Vogt]

They might run fine but what if they are on the verge of dying and low voltage pushes them over the edge?

I would just be sure to get in writing from the customer that they understand the risk.

 

[ptonsparky]

The generator used in my village was a Generac.
No L-N loads.
Left Station control was via a stepdown CT which apparently was not bothered with 240 vs 208 input.

 

[kwired]

They might run fine but what if they are on the verge of dying and low voltage pushes them over the edge?

I would just be sure to get in writing from the customer that they understand the risk.

For induction motors you likely get away with using the 208 volt standby power as long as the motors are not utilized at full rated capacity.

If they are used at full rated capacity and do run for long periods of time then they likely are tripping motor overloads if they were properly set for 240 volt supply.

Resistance heating loads would simply put out less heat. Most the time this isn't a problem unless the heating element is selected with extreme precision and narrow margin of error on the necessary wattage needed, but most the time heating elements are oversized to the needs to some extent and are regulated in some manner to cycle or even vary output to the needs of the process.

 

[ActionDave]

They might run fine but what if they are on the verge of dying and low voltage pushes them over the edge?

I would just be sure to get in writing from the customer that they understand the risk.

Like I said first, the motor is likely to say it can be used at 208V. Even if they don't say it, motors aren't built so on the edge that they fail under circumstances like this. And if they do fail it will likely be because of a bad bearing, or because the motor is short cycling, or because of some other mechanical problem. The #1 rule when you go to troubleshoot a motor problem is that it ain't the motor that's the problem.

 

[kwired]

Like I said first, the motor is likely to say it can be used at 208V. Even if they don't say it, motors aren't built so on the edge that they fail under circumstances like this. And if they do fail it will likely be because of a bad bearing, or because the motor is short cycling, or because of some other mechanical problem. The #1 rule when you go to troubleshoot a motor problem is that it ain't the motor that's the problem.

Or if motor is failed you often find mechanical reasons that contributed to that failure.

 

[hillbilly1]

It is very likely the generator can be reconnected for 120/240 delta. But there are a lot of boxes to check when doing that professionally. But it is far preferable to do it this way.

You might also consider splitting the difference if you are forced to remain wye, 125/216, or 127/220 volt, hopefully the small loads can lived with an increased voltage while the large loads have a less-reduced voltage to work with.

As others have stated, the transfer switch motor might want to be double checked. But the logic can probably be adjusted no problem.

If capable, they are not that hard to change, but the cheaper Generac generators do not have that capability, and they seem to be making inroads to commercial and industrial applications. Most of the Kohlers I’ve installed are easily changed.

 

[Electromatic]

I went over some of the site details this morning. The pump motor nameplates simply say 230/460 (Smith & Loveless). The ATS does have a switched neutral, but it is designated as a 230V switch. It appears to have separately adjustable settings for normal and emergency sources pickup, dropout, etc. I'm going to check with the people who ordered the equipment and the supplier to see if somebody knew and planned this or if it's a screw-up. [I know a lot of generators have huge lead times these days. Maybe this is what they could get.] I may need to check with our water engineer to see if the pumps' reduced performance at 208V is a concern.

 

[electrofelon]

I went over some of the site details this morning. The pump motor nameplates simply say 230/460 (Smith & Loveless). The ATS does have a switched neutral, but it is designated as a 230V switch. It appears to have separately adjustable settings for normal and emergency sources pickup, dropout, etc. I'm going to check with the people who ordered the equipment and the supplier to see if somebody knew and planned this or if it's a screw-up. [I know a lot of generators have huge lead times these days. Maybe this is what they could get.] I may need to check with our water engineer to see if the pumps' reduced performance at 208V is a concern.

As long as the transfer switch can be programmed or set up to work, I wouldn't have an issue with the setup. I would probably just get the client to sign a statement saying the generator provided was not the ideal voltage and that you are not responsible for any motor failures down the road.

 

[Electromatic]

Well, it turns out it was much ado about nothing...The supplier restrapped the generator for high-leg delta but didn't have the corrected factory sticker to put on it before they shipped it out to us!
Thanks as always for the feedback, anyway.

 

[electrofelon]

......no one panic, we can still keep talking about and debating it for a few dozen more posts

 

[hillbilly1]

Well, it turns out it was much ado about nothing...The supplier restrapped the generator for high-leg delta but didn't have the corrected factory sticker to put on it before they shipped it out to us!
Thanks as always for the feedback, anyway.

Manufactures, or their distributors are bad at that. I installed an air screw compressor last year, I made sure the owner ordered 480 three phase. Compressor arrives, has 240 volt stickers all over it. The distributor assured us that it was changed, they just didn’t change the nameplate. I went through and checked all the connections and settings, and they did change it, though done a horrible job on the motor connections.

 

[augie47]

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

 

[Birken Vogt]

If capable, they are not that hard to change, but the cheaper Generac generators do not have that capability, and they seem to be making inroads to commercial and industrial applications. Most of the Kohlers I’ve installed are easily changed.

Most Generacs can be changed even though they say they can't. But you won't get factory support.

 

[hillbilly1]

Most Generacs can be changed even though they say they can't. But you won't get factory support.

Got one sitting in a warehouse right now that you can’t. Not enough leads. Generac uses the cheapest units they can. Maybe they do it differently overseas.

 

[Birken Vogt]

Got one sitting in a warehouse right now that you can’t. Not enough leads. Generac uses the cheapest units they can. Maybe they do it differently overseas.

What configuration is it in and what would you rather it be? I like a challenge now that this thread ran its course.

 

[ptonsparky]

What surprised me with the Village install, was the inspector allowed it.
How do you maintain Phase identification all the way to the motor, when it changes, dependent on the source.
In this case one of those leads should be Orange. (Yes, yours may be different)

 

[Electromatic]

Maybe you could mark the conductors with color-changing LED tape triggered to shift when the source changes!

 

[kwired]

Most Generacs can be changed even though they say they can't. But you won't get factory support.

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