Inverter Questions.

[cookie]

Bernie, does you're inverter have a grounding screw?
You might only have to ground it to the frame of the trailer, like the converter.

Peace
Dave

Sent from my DROID RAZR using Tapatalk 2

 

[happykraut]

Bernie, does you're inverter have a grounding screw?
You might only have to ground it to the frame of the trailer, like the converter.

Peace
Dave

Sent from my DROID RAZR using Tapatalk 2

Dave, yes it does. I hooked it to the white bus bar which is also hooked to the NEG of the battery. It is worth a try. Thanks.

 

[cookie]

Don't hook the ground wire to the neutral buss. Only the white neutral goes to the buss.
Ground it to the frame.

Peace
Dave

Sent from my DROID RAZR using Tapatalk 2

 

[happykraut]

Don't hook the ground wire to the neutral buss. Only the white neutral goes to the buss.
Ground it to the frame.

Peace
Dave

Sent from my DROID RAZR using Tapatalk 2

Dave, I'm bringing it home tomorrow and will change it then. Thanks. See you next week.

 

[happykraut]

OK, all done. I hooked the ground to the frame of the RV. Thanks again to all.

 

[scottyb]

Well, the inverter install is completed minus the fuses. Looks like you have to take out a loan to buy a 300A class T DC fuse plus the mount. Don't know what I'm going to do yet. I ran a fan and then a vac in the bedroom and they worked great. One problem though. The checker shows an open ground which goes back to my original question. I noticed the minus side of the battery is connected to the white bus bar and that is what I used for the minus side of the inverter. There is no ground on a RV until you hook up to shore power. So, do I just live with it??

DBLink ANL Fuse Holder I wasn't expecting much but was impressed with it's durability when I received it. I am using 1-0 cable.

300A Fuses

 

[happykraut]

scottyb, it was mentioned in a post here that I need a Class T DC fuse. A 400A fuse plus holder is $96. I'm sure the 300 would be a little less. I have no idea if your fuse is acceptable versus the Class T DC fuse, but certainly a lot cheaper.

 

[brianharrison]

An ANL vs Class T may be acceptable depending on the max current capable of being delivered by the batteries. This is usually calculated when at lowest voltage before inverter trips out - or if available the battery short circuit amperage.

A 300A ANL I believe is rated at a maximum of 6000 AIC - Ampere Interrupt Current. DC circuit breakers may have to break very high amperages. In such situations, the points inside the breaker may arc over, and may fuse together. The ability of a circuit breaker to safely handle such a situation is its Ampere Interrupt Capacity (AIC) rating (copied from here).

I am using Discover Energy Dry Cell EV Traction AGMs - each has a short circuit of 3,700A - I have a bank of 4. I chose the Class T for its higher AIC, as well as the Blow delay curve for a Class T, was better than the Blow delay curve for an ANL, similar rating.

The increased cost to protect my Xantrex Freedom SW3000 inverter/charger was not a concern for me. Most high end inverter manufacturers recommend a Class T fast blow fuse.

Hope this helps.

Brian

PS - Amazon has Blue Sea Class T 300A fuse ($34) and Class T holder ($41)

 

[scottyb]

Brian, thanks for all that information. I'm not so worried about my "el cheapo" inverter that I am using to run my wine fridge, but I will be more concerned when I upgrade to a high end inverter charger. I have been looking at a Magnum MS2812, and in it's owner's manual it recommends a Class T for it's time delay that allows momentary current surges. So I guess I will be in the same boat as happykraut.

 

[happykraut]

Brian, thanks for clearing that up. Mine is also a cheapo and only plan on using it to run a little fan, an hour or two to run a small TV and brew a cup of coffee. None at the same time. The original cost was $200. A neighbor bought it new at a garage sale with a new box of cables for pennies and then sold it to me for I think it was $20.

 

[brianharrison]

I need to clarify my earlier comments - I said I used the Class T to protect my inverter; this is partially correct. I should have stated I used the Class T to protect my inverter installation - including the wires. In the electrical community experts correctly state the fuse is to protect the wiring. My Xantrex and batteries are capable of high short circuit amperage - the fast acting, high AIC of the Class T is needed to protect the installation - the probable mode of failure in a short circuit case, would be that my wires (2/0) would melt and possible cause a fire.

I used a circuit sizing program similar to this - BlueSea Circuit Wizard - to calculate the wire size, fuse size the 300A, 2/0 gauge, 10ft circuit length (5 ft each way, positive cable and negative cable). I chose to keep voltage drop to less than 2%.

Hope this helps, and does not add more confusion. Apologies on the earlier lack of clarity.

Brian

 

[porthole]

Brian brought up a good point. Keep in mind when sizing wires, with 12 volt DC circuits, the wire run length is calculated using both wires. E.g. battery is 5' from inverter, run is 10'. The current flows out to the load and back.

Been awhile since I was on that page for Blue Sea. If you look on the top right corner they now have an app for phones.