Inverter goes beeeep and shuts off

[PiperAviator]

I'm trying to figure out what kind of load my system can take.

I have a HF 2000 watt inverter and 4 marine batteries wired in parallel.

When I plug in my shop vac, it goes beeeeeep and shuts off. My intentions are to run my well pump in the event of a power failure but I am curious why the inverter does this. Kill-a-watt says the shop vac is sucking up 900 watts.

[thastinger]

My kill-a-watt is not good at detecting the initial starting surge of something like a shopvac, only the running watts.

It is likely that a 12V FLA battery is not capable of providing the discharge current necessary to start the surge the inverter is seeing and also possible you inverter isn't what it says it is. Is the inverter a PSW or MSW type and what brand?

[Sunking]

Because you have a 2000 watt inverter operating @ 12 volts. It is shutting down from being under voltage.

[rba13]

Roadrunner.gif

[john8750]

Just wondering, what size conductors do you have from battery to inverter. You need more than 80 amps at 12 volts, at least #4AWG. Are the batts fully charged? Four batts in parallel is plenty of power. And like mentioned before, starting surge could be a lot.
Hope you find the problem.

[thastinger]

If the inrush of the shopvac is 1200 Watts then you would need the battery to deliver 100 instant amps just to get it going, now factor in the losses in the inverter, say it is 93% effiecient, you need 108 Amps to start it. You are at some seriously dangerous current levels where fires start. At a C/8 discharge rate you could get 50 Amps out of your battery bank assuming they are 100Ah marine batteries, so you should be able to run about a 450W load from your 2000W inverter without the voltage sagging to the inverter cutout point.

[PiperAviator]

Harbor Freight 2000/4000 Given the price I paid, I'm sure is modified sine wave.

[PiperAviator]

Because you have a 2000 watt inverter operating @ 12 volts. It is shutting down from being under voltage.

So, do I rewire the batteries in series? the well pump pulls 1300 watts when it kicks in.

[PiperAviator]

Just wondering, what size conductors do you have from battery to inverter. You need more than 80 amps at 12 volts, at least #4AWG. Are the batts fully charged? Four batts in parallel is plenty of power. And like mentioned before, starting surge could be a lot.
Hope you find the problem.

I am using the thick yellow wire used for wiring houses. 2 Batts brand spanking new, 2 others I've had for a few years. All fully charged.

[thastinger]

I am using the thick yellow wire used for wiring houses. 2 Batts brand spanking new, 2 others I've had for a few years. All fully charged.

You need to stop with that now and buy the proper sized wire, that is 10/2 or 12/2 wire you have from the bank to the inverter if I understand what you are saying. The wire has numbers on the outer sheeve, what do they say? Not to be too dramatic, but you need to unhook all of that stuff and not attempt to use it until the folks here help you get it wired properly, you could get hurt or burn your place down if you don't.

[FloridaSun]

You need to stop with that now and buy the proper sized wire, that is 10/2 or 12/2 wire you have from the bank to the inverter if I understand what you are saying. The wire has numbers on the outer sheeve, what do they say? Not to be too dramatic, but you need to unhook all of that stuff and not attempt to use it until the folks here help you get it wired properly, you could get hurt or burn your place down if you don't.

be dramatic!
hahaha! .... trying to pull near 110amps (the 1300w pump) through a "thick yellow wire used for wiring houses" is outright dangerous. PiperA needs to stop right now and do some serious study about batteries, fuses, wire size, amps/volts/watts, MSW vs. PSW, etc.

[Sunking]

Well if you are using #10 or #12 wire it is seriously undersized. I would also assume all of it improperly terminated unless you borrowed a hydraulic compression tool from an electrician.

[SunEagle]

It is a good thing that your inverter shuts off almost immediately. If it stayed on your big yellow wires would get real hot and probably cause a fire.

If you are trying to draw 1300 watts at 12 vdc you are pulling > 100 amps. If your batteries are wired for 24 vdc then you are pulling > 50 amps. Either of those two voltages will cause the small wires to melt their yellow covering and short.

[PiperAviator]

Lots of info.

You need to stop with that now and buy the proper sized wire, that is 10/2 or 12/2 wire you have from the bank to the inverter if I understand what you are saying. The wire has numbers on the outer sheeve, what do they say? Not to be too dramatic, but you need to unhook all of that stuff and not attempt to use it until the folks here help you get it wired properly, you could get hurt or burn your place down if you don't.

It is 12/2 wire. Boy, I must say, I now realize I have absolutely no idea what I'm doing and maybe I should stop, buy a genny and get an electrician to hook it up just so I can have water during a power outage.

[PiperAviator]

Well if you are using #10 or #12 wire it is seriously undersized. I would also assume all of it improperly terminated unless you borrowed a hydraulic compression tool from an electrician.

I thought the 12/2 would have been fine because that's what the house uses and the well pump plugs into a 110 socket.