power inverter keeps shutting off

You must absolutely put an inline fuse in the positive side as close to the battery as possible. The inverter fuse protects the inverter. The inline fuse will protect the truck batteries.

With the size of cable needed, a short can cause a fire very quickly. There is a lot of current that can be dumped in a short time, and batteries can explode if discharged that fast. Hence the inline fuse.

 

#4 copper wire is good for about 4 feet with a 1500W inverter. For 10 feet, you may need to go with 1/0 (pronounced "one aught", aka 0 gauge. (The next larger size is #00, or 2/0, "two aught".)

You may also be getting bitten by the "modified sine wave meets electronics" issue. Some electronics simply don't work with a modified sine wave (MSW) inverter, and the RoadPro is MSW. Other electronics work, but at a very poor efficiency (higher power use than on "true sine wave" power). A microwave oven is really a high power radio transmitter, and it's quite possible that yours simply doesn't like the power that your inverter is putting out.

Assuming that you have the manual (or can find it online), what is the exact problem that the error code represents? "LV" could mean low voltage, but that could be either on the input (12V) side, or the output (120V) side, meaning excessive power drain. I can see a high power factor (voltage and current are too far out of phase) causing such an error message.

 

You definitely need #4 copper wire. Aluminum has more resistance to it and you're suffering a voltage drop. In fact if you wire in a house service panel you need twice the size aluminum service wire versus copper to carry the same amperage.

Keep the cables as short as possible. Under 4' is ideal, up to 6' is acceptable. Then from the output you can use short extension cords up to 12'. Most likely on one side of the truck a 6' extension cord will do and 12' to feed the other side. If your batteries are back at the tandems put the inverter under the bunk closest to the batteries as possible. Right inside a bunk door sounds ideal. Lift up the rubber flooring and you probably can find a factory access hole that is already plugged. Cut a X in that plug an it will help protect your cables. Also silicone it if you can. That hole is where shorts happen from repeated vibration from the truck. Protect it good.

Yes, use a 150 amp fuse as close to the battery. If the hot wire going through the floor does short that fuse will protect the cables. No fuse and the hot cable shorts then your truck burns down. The inverter fuse just protects from the inverter on. The cables still stay hot. You can get a good deal on Amazon for one of them fuses and fuse holder. They do sell circuit breakers which will work just as good if they ain't cheap junk.

Road Pro is a cheap brand inverter. They have great expensive ones but I've has good success with Cobra which is moderately priced. Amazon seems to have the best deals on them too.

 

also, besides copper cable. try wiring the invertor to opposite batteries too. if you got both ends connected to one battery. and that one battery is junk. you get the LV code.

had that happen on a truck i just started driving. company wasn't worried about batteries as long as the truck started. i rewired to 2 different batteries and all was good till all the batteries went toast.

 

are you running the truck engine while the microwave is on? Put it up on high idle, and watch your engine voltage.

 

Ok so now I have it hooked up with copper wires. Mixrowave runs for about 3secs and cuts off beeping with an opv on the display wth?

 

That's the overload protection kicking. What kind of microwave do you have? Microwaves need ~ twice the wattage to start and it varies from brand to brand. One might need 1100 watts to start and the next brand needs 1500 watts. Also it's possible you bought a piece of junk of eBay. Some of these guys buy stuff at garage sales or flea markets and resell them without even testing them.

Tell me the brand and model # of the microwave and let me check the specs on it. Also what model # is that inverter and I'll check the specs on it.

Another thing run the microwave again and watch the trucks voltage gauge. See if it jumps way up above 14V.