Renogy 3000W inverter shuts down on initial startup

[biker]

Just installed the inverter for the first time and it shuts down with no load. Battery voltage (as measured at the 12V input posts) is within range. Verified the ground directly to outdoor rod is good. I have a 60A fuse from batteries (12V 100AH x 2) to inverter. The 60A fuse trips upon inverter turn-on. I realize that 60A is not nearly enough to support the full 3KW output, but why would it trip with no load? I plan initially to just run a refrigerator. Is there a high inrush current at startup? Doesn't make sense to me. It should only draw < 2.5 A quiescent current, with no load. Any help would be appreciated.

 

[John Frum]

Just installed the inverter for the first time and it shuts down with no load. Battery voltage (as measured at the 12V input posts) is within range. Verified the ground directly to outdoor rod is good. I have a 60A fuse from batteries (12V 100AH x 2) to inverter. The 60A fuse trips upon inverter turn-on. I realize that 60A is not nearly enough to support the full 3KW output, but why would it trip with no load? I plan initially to just run a refrigerator. Is there a high inrush current at startup? Doesn't make sense to me. It should only draw < 2.5 A quiescent current, with no load. Any help would be appreciated.

The capacitors inside the inverter need to pre-charge.
They draw a very large current very quickly.
It looks like a short-circuit to the fuse.

 

[John Frum]

Inverter Disconnect Switch with Precharge

To get the paper, click on the orange button at the top of this page. This circuit is designed as a disconnect switch that allows the user to pre-charge the inverter capacitors before turning the switch completely on. 26 June 2020 update: At...

diysolarforum.com

I've seen a graphite pencil used as a resistor to pre-charge the capacitors.
Also a 100 watt incandescent bulb.

 

[biker]

The capacitors inside the inverter need to pre-charge.
They draw a very large current very quickly.
It looks like a short-circuit to the fuse.

So the precharging needs to be performed at every turn-on? Seems that it would.

 

[John Frum]

So the precharging needs to be performed at every turn-on? Seems that it would.

Pretty much.
On some units the caps dissipate their charges pretty quickly on power-down.

 

[rmaddy]

So the precharging needs to be performed at every turn-on? Seems that it would.

It's my understanding that most inverters only need to be pre-charged when reconnecting power. Once connected, turning the inverter off and on using the inverter's built-in switch should not require pre-charging.

 

[MrNatural22]

Pretty much.
On some units the caps dissipate their charges pretty quickly on power-down.

Yep, I have to precharge my Samlex each time after it being shut down for even a few minutes.
Most inverters will dissipate the caps charge from those I've spoken to.

 

[John Frum]

Yep, I have to precharge my Samlex each time after it being shut down for even a few minutes.
Most inverters will dissipate the caps charge from those I've spoken to.

OP can test that.