Standby inverters

kcopp

With winter and possible storm outages looming I got to think about back up power supplies.
Yes you can get a generator and the whole transfer switch set up....

With today wall hung boilers using around 120W and ECM circulators using 60 watts or less how about a simple battery inverter....
The battery technology has come a long way in the last few years.

A simple power cord wired into the boiler circuit could get you up and running for several hours.
Milwaukke and DeWalt have some portable power supplies w/ their 18/ 20V platforms.

Anyone tried this? What makes/ models have worked?

Jamie Hall

Um... well... you'd be in violation of any known electrical code, if that bothers you. If you do do something of the sort, the boiler must be connected via a plug into a wall outlet which you would have to unplug from the wall outlet and plug into your alternate power supply. This is where the code violation comes in (a heating boiler is a fixed appliance, and must be hard wired).

Do NOT, under any circumstance, wire an alternate power supply into your house wiring without using an approved transfer switch which breaks both hots from the grid mains before allowing the alternate supply to be connected. Otherwise you will back feed the grid. Even if that doesn't blow up your alternate power supply, it will energize the grid in your area, and the linemen who are trying to reconnect you don't like being electrocuted...

Yes, I know people do it. It's unsafe and may cause equipment damage, at best. At worst, you'll kill somebody.

kcopp

Jamie... of course I would isolate the power from the house. I know A LOT better than that.
Most wall hung boiler do come w/ a plug. So not all are hard wired.

WMno57

Runtime per battery? I don't think any of the 18 volt battery platforms have enough capacity / runtime. Check my math at the bottom of this post.
I don't like maintaining multiple battery platforms. Currently have 2. Milwaukee M12 and Ryobi 18v. I might add a third platform to that for an Inverter, chainsaw, and big shop-vac. Already have 18v chainsaw and 18v shop-vac though.
I live in the country and have a power outage about once a month. Couple days ago it was 5 minutes. Longest in 5 years was 12 hours. My neighbors tell me there have been multiple day outages in the past. I have about a dozen generators, but am interested in adding a battery powered inverter to my generator collection.
Been looking at the Ryobi 40 volt Inverter for $650 (tool only). The Ryobi is not an Uninterruptible Power Supply (UPS). You can't run off it all the time like you could with a computer or data center UPS.
https://www.ryobitools.com/products/details/46396036582
But maybe Stihl would be a better 40 - 60 volt platform?

Milwaukee's largest 18 volt battery is the HD12.0.
12 amp hours?
18 volts x 12 amp hours = 216 watt hours
75 % efficiency (just guessing) of converting 18 v DC to 120 volt AC
162 watt hours of 120v AC
120 watts for boiler + 60 watts for ECM circulator = 180 watts.
162 /180 = 0.9 hours
54 minutes of run time per battery
$227 per battery (must buy 2 for this price)
https://www.supplyhouse.com/Milwaukee-48-11-1852-M18-Redlithium-XC-5-0-Extended-Capacity-Battery-Pack-Two-Pack

WMno57

Or I could get a Prius and and used Data Center UPS. And build a PriUPS. Would that be OK with you @Jamie?
http://www.priups.com/riddle/answer-1.htm

ratio

Most load centers have a generator interlock kit that places a mechanical interlock between the main & one of the top two-pole breaker positions to back feed the panel once the main is off. I pretty much install one on every service I change out, because I can't see electricity becoming more reliable in the coming years.

Jamie Hall

Hey. As long as you have a positive way to prevent backfeeding the grid -- whatever works! @ratio ;s approach to new or rebuilt installations is a good one, and cheaper than a transfer switch.