Hello

I suggest reviewing documentation. I think this is the support page for the UPS.

https://www.dell.com/support/home/product-support/product/dell-online-rack-ups-3750r/research

As long as the input is the appropriate type, AC or DC, and is providing voltage and amperage that is within supported specifications then it should work.

Thanks

I actually just figured out how to do it through the front panel.  I was confused how to actually get into the menus there.   I was able to change the output voltage from 208 to autosense and everything seems to be peachy now.  The units (I actually have 2) are happily running alarm free in bypass mode. 

I did actually read the manual, that's where I got the number for max voltage I mentioned.  

Nowhere in the manual(s) did I find it mention anything about setting input voltage thresholds like I can do with my APC units.  I am not very familiar with these dell units and did not originally set them up.  

What I found when I powered the unit up with 240VAC is that they will not go to bypass mode.  The input voltage is too high.  The output still works fine, however it is regulated down to 208.  It would be nice if there were settings somewhere I could change.

I did find the pinout for the serial cable I think, maybe config is there?

Youre using an old Dell (Eaton based) 3750 Watt UPS which goes end of sale 4 years ago.  We have 3 dozen of them left in production and they all run on 230V here.

Regards,
Joerg

Hello,

I know this is an older thread but I was hoping someone might still be able to answer a question for me.

Can anyone tell me if these could be used in a residential environment using either 120v or 220v (which is actually 240v)?

I greatly appreciate any information!

-Sam

It works just fine.  Make sure you don't have any loads connected when you power it in. You will need to go into the menus and set the correct input and output voltage and tolerances.

I have had 2 running perfectly on 240v single phase since I started this post.  I recently acquired 2 more that I plan to hook up the same way. 

Why do you say that? 

Genuinely curious, as they are well within their ratings.  I realize it's not a "standard" installation, but we aren't running anything out of spec. 

Hello, I would highly advise AGAINST it. Good chance of fire.

OK.... Pg63 doesn't have any useful information.

"because I said so" doesn't mean . TOS76>

.  Just because it's not an "approved" installation, doesn't automatically mean it's a safety hazard.  If you look at the speciations/ratings of the equipment, and have half a brain to interpret them, there should be no adverse effect running on 240v single phase.  It is not explicitly prohibited.  If it were so dangerous, why is it not called out as such in the documentation? 

It is possible to use but I would still say it's risky and if you don't use the right model it could be damaging to UPS and could lead to fire.

chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/https://dell.to/3hT9MpC

Dell Online Rack UPS 3750W and 4200W User's Guide
If you look at page 63, table 9 , UPS model list, they are all different.