Finally scored a whole house sine wave inverter!

[rcavictim]

I've been looking for a large capacity single phase inverter that uses a practical low voltage like 48 volts now for a whole decade and last Thursday I finally found one.  I put a deposit on it and on Saturday returned to the vendor with a trailer and helper to pick it up.  It is one heavy piece, weighing about 600 lbs.  I had to rig a wire rope electric winch to ease it down the stairs into my house basement.  The weight was completely straining and bending the axle on my wheeled dolly.

Most of these surplussed commercial system UPS inverters are either 3-phase or require a high voltage battery bank, like 200 VDC or higher for operation.  As discussed elsewhere such battery banks can be a bomb waiting to go off as all the current is forced through every cell.  If one cell goes high impedance it can grenade and cause damage and a fire or worse.  A 48 volt plant with lots of parallel batteries is not nearly as dangerous, nor is it the shock/electrocution hazard of a high voltage pack.

The unit I got is 10 kVA and delivers clean filtered sine wave power at 50 Hz or 60 Hz user selectable and  single phase voltage from 115-125 VAC at about 85 amperes or split phase 120-0-120. It will drive full power into any load leading or lagging power factor up to 30 %. The frequency and voltage can be fine tuned as can lo and hi limits on the auto switchover from the incoming AC mains when used as a UPS.  It also can be set as a stand alone inverter that does not need AC mains reference to start or run.  The auto/manual transfer switch is internal, the massive battery charger is not part of this unit.  The diagnostic start up and transfer functions are all under microprocessor control.  The unit is spotlessly clean inside.

Until I found this I was gathering up all the 12 volt inverters I could get my hands on within a tiny budget.  I was going to use basically one inverter per breaker box circuit.  Some of these are mod sine inverters, some are sinewave inverters.  Quite a hodge podge.  This single inverter makes life much simpler.  One high quality sine wave inverter to drive the entire existing breaker panel in the house.  The switchover function can be used to connect the house panel to my diesel genset in the other building when I wish to take advantage of a generator run to do laundry, or manage other infrequently applied high power loads.

Pics of the unit as found now sitting in my basement are attached.  I am so worn out from moving it yesterday I haven't had the energy to touch it yet.  Notice the two battery terminals are four lengths of AWG #4/0,  2000 volt, 90C rated marine shipboard cable date coded 1999 and looking like brand new.

I have batteries now too as of a fairly recent acquisition so I can be ready for my wind turbine when that is done, hopefully this year.

This kind of project when so much is DIY and on a miniscule budget can take a good many years to complete. I am relieved that I am now close to having an operational off-grid system.  I can't wait for the day I contact the enemy and demand that they terminate the uninterrupted flow of crippling power bills to my post box. 

[Tom Reed]

Just curious, what is the idle current on that bad boy?

[rcavictim]

Just curious, what is the idle current on that bad boy?

Good question!  The manual I have for the equipment does not mention that spec.  I did not measure it during my brief field test at the vendor's location. Once I get it physically into it's final resting place I can use the same 50 AH battery pack I used to field test it to get a idle current spec.

[mobile_bob]

if you find the idle current is too high for your liking, you could always use it only for those heavier loads and get
a smaller unit to cover the continuous loads that has a lower idle current

exeltech units are available on ebay, in 48volt versions, pure sinewave and anywhere from 250-1100watts output

just a thought.

nice score btw, probably about bullet proof too

bob g

[rcavictim]

if you find the idle current is too high for your liking, you could always use it only for those heavier loads and get
a smaller unit to cover the continuous loads that has a lower idle current

exeltech units are available on ebay, in 48volt versions, pure sinewave and anywhere from 250-1100watts output

just a thought.

nice score btw, probably about bullet proof too

bob g

I had thoughts of maybe rewiring just the lighting in my home so it is all on one or two circuits that I could run from a much smaller 48 volt inverter.  I have several computer UPS's that are anywhere from 1400 watts to 2200 watts sine wave output that run off a 48 volt battery bank.  Just picked up a nice Compaq this weekend that uses an external battery box and delivers 1400 watts..  Tested it out today and it is AOK.  Quiet too.

[WGB]

Good deal!

[cschuerm]

Sweet!  I've been looking for something just like that for quite a few years myself.....
Congrats!

chris

[veggie]

 Whoa !

You don't do anything in a small way do you !
Nice unit.

veggie