Feedback on 1012LV-MS design for UPS backup

[monochromatic]

Hi, this is a follow-up to my previous post after learning a lot the past few days. Thanks to all who replied!

My goal is to make this as safe as possible, as I want to mount this in a closet in my house (maybe a bad idea?). Here is my design so far:





Does anything look wrong in my proposed setup?

My questions as listed in the image:

• The 1012LV-MS user manual says: "CAUTION!! Before connecting to AC input power source, please install a separate AC breaker between inverter and AC input power source. This will ensure the inverter can be securely disconnected during maintenance and fully protected from over current of AC input. The recommended spec of AC breaker is 10A for 1KVA, 20A for 2KVA, 32A for 3KVA, 40A for 4KVA and 50A for 5KVA." The 1012LV-MS will be plugged into a 20 amp GFCI outlet, so are they saying I need another 10 amp breaker before it plugs into this outlet? Very confusing for me.
• I've read all the threads about the MPP ground/neutral bond and yet... still don't seem to have a clear answer. Basically since this unit will be plugged into the outlet full-time, it can use the G-N bond at the main panel in my house. Do I need to short the dry contact ports to always use the main panel's ground neutral bond?
• The goal of this build is safety. I want to be able to leave my house for a week and not be concerned about the house burning down. All of the battery cables will be run in conduit as much as is feasible, I'm going to use a Class T fuse even though it might be overkill, etc. What would make this safer? I've thought about enclosing the entire setup in a metal utility closet with some fans, lined with drywall in case of an inverter or battery fire.

Thank you!

 

[JAS]

I'll give you my thoughts

• Tie the in and out neutrals together to get N-G Bond when running on battery. EDIT: MAKE SURE TO LEAVE THE AC INPUT PLUGGED IN
• Not sure why MPP wants a 10A breaker on the AC input. Breakers are normally there to protect wiring. As long as the wiring can handle your 20A circuit, I don't think you need a separate breaker. Besides, the unit will overload before it can produce 20A anyway. I guess you could put a powerstrip in between. They normally have around a 10A breaker built into them.
• Safety: At least make sure everything is mounted on a non-flammable surface

 

[Shimmy]

You likely do not need the battery switch or class-T fuse with a single battery. You might try the marine-rated terminal fuses instead since it is just 12V. (The battery switch is a good idea, it just might not be absolutely required.)

A metal box to put everything in is the best approach for safety.

 

[JAS]

I would be concerned about putting the MPP inside of another box. You'd want to make sure it is well ventilated. Someone else had posted a diy solar generator using the 1012 inside of a large plastic toolbox. I asked them how hot the unit got inside there and they said it got pretty hot very quickly. They had fans mounted on the box for ventilation.

The MPP unit itself is already a metal box. If anything lets out smoke inside, it may briefly flame up internally. But, I expect it would burn itself out pretty quickly and all you would see from the outside is smoke coming out. If it burns badly enough to short out on the metal, it should trip your AC input breaker...

 

[patrickcasavant]

Hi @monochromatic! How do your setup go? I plan to do the exact same thing!
Did you run some tests? Your servers, switchs and routers dont have any problem with the ~10ms transfert delay?
Thanks!
Pat

 

[JAS]

Finally getting back to this...

I'm running my Internet, WiFi, Switches, etc. on my 1012 MS. It runs mostly off of solar/battery and only switches to AC when the battery percentage drops. I've had no issues with anything rebooting during the Transfers to/from.