Inverter Installation Question

[Boatsb]

As you explain the problem it does not sound like any damage should have occurred. When checking on a system like you are installing, using the voltage setting on the meter, it is best to put the negative probe on the source negative, like the wire going directly to the battery negative terminal. Using this method, with the breaker off check the voltage on the wire coming from the battery, if should be battery voltage, now turn on the breaker, and measure the voltage on the other connection on the breaker, it should read the same on both terminals. If you think there is sufficient charge on the capacitors to give you a reading, you can either turn the breaker off and recheck the voltage at than point, or disconnect the wire on the load side of the breaker, and recheck.

I would be hesitant to just put in a fuse and switch, the breaker is a safety device to protect the equipment, a fuse my not blow as fast a the breaker can open, this could compromise the protection needed for the equipment.

No a breaker is not the recommended safety for a charger / inverter. First of all the fuse size should be 400 amps. Second a breaker is calibrated for only one direction. You will electrons flowing both ways.

[Boatnut]

No a breaker is not the recommended safety for a charger / inverter. First of all the fuse size should be 400 amps. Second a breaker is calibrated for only one direction. You will electrons flowing both ways.

I had to go back and recheck the picture, I was thinking the breaker was included in the inverter. Why a fuse would be recommended, I don't understand, but a fuse where the breaker is located will certainly work OK.

As for your second comment about a breaker being calibrated one way, is a theory that is way beyond my understanding, never heard it, and don't get it. Do you have a reference that explains it.

[Boatsb]

I had a breaker reversed on an inspected vessel and was told to reverse it. I contacted the manufacturer's engineering department and they explained the trip apparatus was designed for a single direction on dc breakers and that it would probably trip in the other direction at about the same amperage but would not be within the design tolerances of the breaker. May take more or less in the other direction .

[Boatnut]

Thanks Scott, that's a new one on me. It kind of makes sense though for a dc breaker. I don't know why anyone would reverse line and load anyway, if they do they have no business working on it in the first place.

[Boatsb]

some breakers are mirror images of others and can be mixed up pretty easily if your eyes are not great in the dark

[Boatnut]

Trying to help people on this forum has gotten ridiculous, it seems someone always knows more than the next guy, if they don't, you get some off the wall smart a$$ remark, or some kind of theory that is not pertinent to the problem. I can not say I have ever seen a quality circuit breaker that is not clearly marked line and load, and if is not marked clearly don't buy it, it is junk. It doesn't seem like a wise idea to work on electrical equipment in poor or insufficient light.

To get back to the subject at hand, Vincent how are you making out with the inverter? If I can be of help PM me, and it can probably be easily solved with a phone call. If you decide to go with fuses, check with the manufacturer to clarify what type of fuse to use. They probably specify what type in the manual. It can make a difference.

[Vincentc]

Thanks,
Job work has been interfering with boat work . The battery bank had sat up and gone down. Once I get it charged I will see if everything works. Magnum seems insistent that I use 400 amp protection, either fuse or breaker. For now, I intend on checking the breaker flow and see if it all works.

Regards

[Boatsb]

Trying to help people on this forum has gotten ridiculous, it seems someone always knows more than the next guy, if they don't, you get some off the wall smart a$$ remark, or some kind of theory that is not pertinent to the problem. I can not say I have ever seen a quality circuit breaker that is not clearly marked line and load, and if is not marked clearly don't buy it, it is junk. It doesn't seem like a wise idea to work on electrical equipment in poor or insufficient light.

To get back to the subject at hand, Vincent how are you making out with the inverter? If I can be of help PM me, and it can probably be easily solved with a phone call. If you decide to go with fuses, check with the manufacturer to clarify what type of fuse to use. They probably specify what type in the manual. It can make a difference.

Craig the older airpax uses the dame form factor as a carling but the poles are reversed. Also the marks are sometimes molded on the black plastic and almost impossible to read in less than bright perfect light.

Fuses do not care about polarity. There is not a trip mechanism. They also do not reset so spares are a must..

[GJH]

Thanks,
Job work has been interfering with boat work . The battery bank had sat up and gone down. Once I get it charged I will see if everything works. Magnum seems insistent that I use 400 amp protection, either fuse or breaker. For now, I intend on checking the breaker flow and see if it all works.

Regards

A 400 amp breaker costs as much as the whole system. Get the T fuse and block Magnum specifies, they sell one but others do too. Just do a search on 400 amp T fuse.

[Vincentc]

A 400 amp breaker costs as much as the whole system. Get the T fuse and block Magnum specifies, they sell one but others do too. Just do a search on 400 amp T fuse.

That explains why I didn't find a 400 amp breaker. Magnum appears to sell a mounting panel which includes a breaker, but I have not seen it for sale. I have a the fuse assy and switch but thought a 200 amp breaker would serve. Not a big deal to change. Practice makes it easier if not perfect.

Regards