Inverter change over problem

[richmon74]

I have a 2500W n a 2000W in inverter both powered by eight 200AH battery (of same type) connected to produce 48V

it worked perfectly the first time of installation but latter when the public power goes out the inverters will shut down immidiately even when the betteries are fully charged.

what could possibly be the problem plz someone help

 

[GusM]

What is this some type of commercial backup (APC or something)......... is there software with it to test it for powerfailure.


I had a small APC before that would only work with a powerfailure ....... you coundn't use it as a straight inverter and have it power equipment by batteries alone. I'd have to look it up there is generally two "types" of inverters for backup units.

 

[richmon74]

it's a heavy duty inverter not the small ups

 

[marie65]

What means "public power" goes out. Are your inverters connected in the grid power? I mean, are you generating power in the grid from an alternativ power source (solar, hidro etc)? If it's so, when your main power shut off, you have to disconect your inverters from the grid instantly and let them only to power your home.

 

[richmon74]

What means "public power" goes out. Are your inverters connected in the grid power? I mean, are you generating power in the grid from an alternativ power source (solar, hidro etc)? If it's so, when your main power shut off, you have to disconect your inverters from the grid instantly and let them only to power your home.

it's automatic inveter. it's suposed to change over to battey power during power outage. the regular public power not any solar etc..

 

[Ante]

Do you mean that its output is paralleled with the “public power” at all times?

 

[Buriedcode]

hi,

Really out of my depth here, I'm not a 'power' man, and I've never worked on such a device. Just so you know.

As a back up system, I would assume it is fitted between the public power grid, and the local grid (of a shop/house/factory/hospital etc..) and as you said, only operating when there is no external power from the public grid, ie: a power cut. I assume its a comercial device, so I can only assume that the actual 'inverter' part is ok. I find it hard to believe a company would sell such a device with no over-load protection, so it should be something simple, maybe a circuit breaker has blown? Or a relay?
How much power (on average) are you drawing from this/external power? Because, say you've got your 2 and 2.5kW inverters, the main grid is good, and you're drawing 6kW, then the public grid shuts off, your inverters cannot supply that much power.

Maybe its the connection to the external grid thats at fault. If it doesn't know when theres a power cut, it won't turn on. So the 'automatic' part might be at fault.

Have you tried shutting off the external mains while the inverters are in operation? With, say, only 500W power being drawn?

Sorry if this is of no use, but problems are there to be solved, and 'brainstorming' is what I do.

BuriedCode.

 

[richmon74]

i've solved the problem. it was insufficient current flow from the battery to the inverter. the diameter of the cable they used to connect the battery was to small and the distance between the battery and the inverter also was too long