So I just blew 2 300 amp ANL fuses on the input to my inverter. It is a newer install. 3KW inverter/charger with 4/0 cable. I think I am fusing it correctly but this is what happens. Plugged into 20a house plug with 1 AC on and the fridge. Both are on the same leg. 1st time is happened I had my shop vac (a small one) plugged into the outside GFCI plug and was cleaning out the basement from all the debris left behind from the manufacture. It tripped the inside breaker and I come back out and the fuse is blown. The other time I accidentally turned the 2nd AC on thus tripping the breaker again. I get that the inverter can not handle the load but why kill the fuse and not just shut down? Kind of has me a bit concerned since I am leaving for a trip on Monday.
Fuse size
- Thread starter orion7144
- Start date
SNOKING
Well-known member
At 3000 Watts, you are getting close to 300 amps. If your inverter is trying to put out more than 3KW, then the fuse at 300 is most likely going to blow. One must manage load if the inverter is powering the whole trailer. Was the water heater also on AC? Chris
SNOKING
Well-known member
I think he said that he trip the breaker in the house and dropped the load onto the inverter. Chris
Correct. The AIMS inverter charger has a 6kw surge. Only breakers in the rv that are on are the refrigerator and ac. Both are on the same leg and that leg is fed from inverter. I usually turn off the ac before turning other things on. I do this the day before coming to cool off fridge and camper before we go. Thinking I need to move main ac to other leg. Also with fridge and ac in show 15a on the progressive industries.
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L1 is going to inverter then main panel. L2 is fed straight to panel. All breakers on L2 were off. I have a 30a breaker feeding the input ac to the inverter. Maybe I need that breaker on the output.
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danemayer
Well-known member
I'm guessing you're trying to say that shore power L1 goes through a transfer switch built into the inverter where either the inverter output or the shore power L1 is fed to the breaker panel. And shore power L2 just goes straight into the breaker panel.
So if I have that right, when you tripped the 20 amp circuit in your home, the transfer switch flipped and started pulling power from the inverter output instead of shore power, and the fuses between batteries and inverter blew.
Have you checked battery voltage under load. Maybe a bad cell? Loose connection?
carl.swoyer
Well-known member
Orion, gave this a quick look over this morning. L1 &. L2 from shore power should go to L1&L2 in the transfer switch in. From there to each leg on the RV distribution panel. From the inverter , (using my Magnum Ms2812 set up) hot 1 & hot 2 out you need to identify the two RV circuts to be powered. Disconnect the wires from the respective RV circuits and wire them to the inverter hot out. They now are
"not"connected to the RV distribution panel.
I brought the above subject to lite because if you piggy back the inverter hot out to the rv distribution panel you are back feeding the RV panel which may explain the blown 300 amp fuse.
My Magnum Inverter has pass thru technology.
Hopefully this made sense.
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carl.swoyer
Well-known member
Forgot to ask, what is the model number of your inverter.
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carl.swoyer
Well-known member
Are the hot outs from your inverter going to the RV distribution panel?
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danemayer
Well-known member
If the neutral wiring is as shown, depending on how the inverter's transfer switch handles the neutral line, a loss of power on L1 while plugged into shore power and using both L1 and L2 could open the neutral which is also needed by L2. This would be a very dangerous situation.
But maybe the neutral connection in the inverter is a passive pass-through rather than being actively switched.
You might want to get some advice from a licensed electrician familiar with your inverter. If you get it wrong, the consequences could be severe.
carl.swoyer
Well-known member
You should have a dedicated hot in , from the RV distribution center to the hot in on the inverter/ charger. This is needed to let the inverter charger sense the absence and or presence of shore power.
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L1 is dedicated to the inverter first then distribution panel. I will check and see if the neutral is a pass through. Everything works fine on 50A power. I have had this setup for a few weeks and this was the 2nd time plugged in at home. It was the first time I tripped the house breaker after turning on the 2nd AC by accident and again when I was running the shop vac. Never blew a fuse before.
carl.swoyer
Well-known member
I'm feeling a little concerned. I think your wiring is wrong..
Im certain that the current setup is back feeding the RV . 120 volts going to the panel both from shore and from the inverter at the same time. That would be why the 300amp fuse blows.
Yes this will work until you plug in to shore power.
You cannot have any hot feed from your inverter to the RV main distribution center. As Dane mentioned passive pass through technology from the inverter will keep the circuits hot when toggling between shore power and inverter/ dry camping.
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The power panel is a split panel. L1 supplies half and L2 supplies half. They are not on the same circuit. It is like having 2 separate power panels in a house. They do share the neutral so I will be looking into that today. The AC and fridge have been on all night without issue.
In case it comes up I am running my 50A cable to a 30A dogbone with a 45' 30A rv extension cable to a dogbone to my 20A receptacle in the garage. I do have plans on changing the 20A outlet in the garage to 30A once camping season is over and I have some time.
FYI my experience with electronics is extensive (10 years military ET and 22 years and counting as a Semiconductor Engineering Technician)
The whole purpose to run the inverter to supply half of my power panel is to run the refrigerator and microwave on quick overnight stops. I can not put both AC's on one leg so I am forced to keep them separate thus having to remember to turn the breaker off if running on battery power.
If I forget (while NOT on shore power) the AC does try and come on and you can here the inverter beep a few times before shutting off but it does NOT kill the fuse.
Another option to try and reduce the load is to swap the bedrooms 13.5K AC to the inverter leg.
I am running 4 235ah 6V batteries in series parallel.
In case it comes up I am running my 50A cable to a 30A dogbone with a 45' 30A rv extension cable to a dogbone to my 20A receptacle in the garage. I do have plans on changing the 20A outlet in the garage to 30A once camping season is over and I have some time.
FYI my experience with electronics is extensive (10 years military ET and 22 years and counting as a Semiconductor Engineering Technician)
The whole purpose to run the inverter to supply half of my power panel is to run the refrigerator and microwave on quick overnight stops. I can not put both AC's on one leg so I am forced to keep them separate thus having to remember to turn the breaker off if running on battery power.
If I forget (while NOT on shore power) the AC does try and come on and you can here the inverter beep a few times before shutting off but it does NOT kill the fuse.
Another option to try and reduce the load is to swap the bedrooms 13.5K AC to the inverter leg.
I am running 4 235ah 6V batteries in series parallel.
Water heater is on L2. I did measure the neutral with all power off to the inverter and it does NOT pass it so that is probably my issue.
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I put the 300a before the inverter to protect the inverter. It has a 9KW surge but I figure if I mess up and turn too much on like I did it will kill the fuse before the inverter. Are you suggesting I put a bigger fuse in?
- - - Updated - - -
I put the 300a before the inverter to protect the inverter. It has a 9KW surge but I figure if I mess up and turn too much on like I did it will kill the fuse before the inverter. Are you suggesting I put a bigger fuse in?
carl.swoyer
Well-known member
Try this test.
1 Disconnect shore power.
2 Get a volt meter.
3 Turn on your inverter.
4 Test each leg on the shore power cord. Be careful as they might be hot if you are in fact back feeding the RV distribution panel.
If the prongs on the power cord are hot while the inverter charger is on you have a very dangerous set up.
Also if you're running the AC unit off the inverter/ batteries you're probably boiling the batteries. Another scary application.
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1 Disconnect shore power.
2 Get a volt meter.
3 Turn on your inverter.
4 Test each leg on the shore power cord. Be careful as they might be hot if you are in fact back feeding the RV distribution panel.
If the prongs on the power cord are hot while the inverter charger is on you have a very dangerous set up.
Also if you're running the AC unit off the inverter/ batteries you're probably boiling the batteries. Another scary application.
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