Bonding nuance

[Bluedog225]

I’ve got my entire system set up in a conex box. I set up a uni-strut cage so that I could mount various pieces of electrical equipment. [edited for spelling] Quattro, main panel, cerbo , MPPT, etc. And a large metal shelving unit for the batteries.

All this stuff is bolted together. That is, the Quattro, main panel, etc are attached with nuts and bolts. And the metal bookshelf it similarly attached to the strut.

My earth ground conductor runs to the Quattro.

Everything I’ve mentioned above shows basic continuity on the multimeter. And I plan to run a jumper wire from the ground wire to the conex box itself.

My first question is whether I need to run jumper wires to and from each piece of equipment? Some have grounding attachment points, some don’t.

I’m thinking yes, I do need to. The NEC just says “connected together.” They are definitely connected. But I’m not sure whether my incidental connections establish an effective ground-fault current path.

My second question is what is the maximum fault current? 5000/120 for the inverter is 41 amps. The batteries are 48 volt and 100 amps each. How would calculate that? Maybe limited by the 225 amp class T fuse?

Thanks

 

[sumpower]

I’ve got my entire system set up in a conex box. I set up a uni-strut cage so that I could mount various pieces of electrical equipment. Quattro, servo, maintain, MPPT, etc. And a large metal shelving unit for the batteries.

All this stuff is bolted together. That is, the Quattro, main panel, etc are attached with nuts and bolts. And the metal bookshelf it similarly attached to the strut.

My earth ground conductor runs to the Quattro.

If the earth ground wire you are discribing goes to two ground rods, then it needs to be connected to the AC panel and nowwhere else. There should be a green bonding screw in the main panel that bonds the panel (neutral and ground bonded at this point and no where else).

Everything I’ve mentioned above shows basic continuity on the multimeter. And I plan to run a jumper wire from the ground wire to the conex box itself.

Ground wire from conex needs to be attached to one of the ground bars in the main panel.

My first question is whether I need to run jumper wires to and from each piece of equipment?

No, A Ground wire needs to be run from the ground lug in the main panel to the inverter. A ground wire should be run from the inverter to each DC source.

Some have grounding attachment points, some don’t.

I’m thinking yes, I do need to. The NEC just says “connected together.” They are definitely connected. But I’m not sure whether my incidental connections establish an effective ground-fault current path.

My second question is what is the maximum fault current? 5000/120 for the inverter is 41 amps. The batteries are 48 volt and 100 amps each. How would calculate that? Maybe limited by the 225 amp class T fuse?

Max fault current involves a calculation that includes the length and size of the conductor from the inverter or from the battery to the inverter. T class fuse is sufficient for small system fault current as it will be less than the 10,000amp rating of the fuse.

Thanks