If you are having these problems, it would seem that others would be as well.
Are they?
It's really no different than it can be in our homes, when/if we overload the circuits, with too much plugged into one plug or plugs that are all wired together. Often happens in the kitchen and we just get to know what not to do!! When you think of it, it's a wonder more do not have this problem at other sewing groups. Granted, some do/have, then after figuring it out, work around it. Example, I know one group that goes to a facility, and they have their irons in a different room. Not so much because of space, or to force movement/exercise, but because they just know they get into electrical problems.
As
@mkc already described, a surge protector only deals with surges/spikes. Whereas a UPS deals with both the highs and lows (called brownouts) as effectively you are running off a battery all the time. The power goes into the UPS, and is then stored, so that you can get the right output as you need it. I've had UPS' on my computers for over 30 yrs, eventually adding my sewing machines too. Not sure how small you can get one ... but the ones that I have are a lot more weighty than I would want to be slugging to take to a sew-day! At the least you can do some queries, and see what might work for you.
Aside from your noting your sewing results are not up-to-par when this happens ... you need to be aware, that using your machine without the correct incoming power, can do damage to your machine. That's why 30+yrs ago, I had to get a UPS ... effectively the brains of my home computer were destroyed! And why, I will always use a UPS.
However, all this might be something that needs to be discussed by the whole group. Maybe the location needs to be reconsidered? Or acceptable alternatives discussed/decided?
BTW there are also whole-home UPS' that can be installed. Not the priciest either ... and might be a good and realistic option for sewing group locations. However, that's something that only an electrician could advise, based on the specifics of the location.
@Chuck2012 while you have noted ...
Originally Posted by
Chuck2012
This retreat is at a hotel with a large conference center. Wonderful space…except for the electricity.
... keep in mind that the electricity for the room, was probably not designed for so many sewing machines running at the same time! Have discussions been had with the hotel people? If they value your group's business, they may be willing to do the changes needed, to maintain the business ... and perhaps increase their usage for your events.
Good Luck !!