Operating from battery

[mmckenna]

I have to wonder if not putting a fuse on the negative side is a partial transfer of the idea of never fusing a ground in A/C circuitry.

Whatcha think?

Thanks Joel

In a vehicle with a negative ground system, it seems like there aren't really any benefits.

The benefits that people claim are usually centered around resolving issues that would come up from really awful lack of vehicle maintenance. Like losing the chassis ground connection from the battery. Letting that happen would probably be exceptionally stupid and indicate a complete and total lack of understanding of the very basics of electrical work. Anyone who would willingly ignore the basics like that probably shouldn't be monkeying around with anything sharp or electrical.

 

[AK9R]

Like losing the chassis ground connection from the battery.

And, it ignores the fact that on a modern automobile, losing the chassis ground connection to the battery will probably throw up all kinds of codes. Of course, it seems that the typical American driver ignores check engine lights and drives around with them illuminated anyway.

 

[krokus]

I have to wonder if not putting a fuse on the negative side is a partial transfer of the idea of never fusing a ground in A/C circuitry.

Whatcha think?

Thanks Joel

Electricians are scary around electronic/vehicular wiring. They do not understand why the black wire is not hot. (Nor why wire nuts are not a good idea.)

 

[MUTNAV]

ok... one more question then (real question), when a mobile is used in a home setting, would it help for it to be fused on both side?

Thanks
Joel

 

[mmckenna]

ok... one more question then (real question), when a mobile is used in a home setting, would it help for it to be fused on both side?

Thanks
Joel

No. The fuse is there in the event there is a fault that results in an over current condition. One fuse on the positive side would open if there was a fault.

Same reason the A/C circuit breakers in your house are only on the hot side of the circuit.

 

[MUTNAV]

Ok... I lied, I have another question. When a mobile is put in a home, does the chassis of the mobile require a separate ground.

I ask this because at one point a co-worker was working on a GRC-206 (MRC-144) and when hooked up to a grounded portable generator, (through a built in ac/dc power supply (3 wire)) , the chassis of the equipment became hot (it may have been an add on power supply since it was the only piece of equipment that was bare metal, the rest was olive drab).

I was the only one to recognize it because I've been shocked enough to recognize the 60 cycle buzz / shock when touching equipment, ( I had to prove it to him with a multi-meter connected between the chassis of the equipment and another probe stuck in the ground.

The words "isolation transformer" keep coming to mind, but I don't know if it would have helped, or if everyone should have one with mobile equipment in the home.

I appreciate helpful answers to this kind of question.

Thanks
Joel

 

[mmckenna]

Sounds like a wiring fault.

Yeah, the equipment should be grounded. Usually building out a ham shack or any radio facility -everything- gets bonded to a common ground. Electrical outlet grounds are not sufficient. There's usually a ground buss somewhere in the room, on the rack, or a 'halo' ground above the equipment racks. Every chassis (radio, power supply, etc) gets bonded to that so everything is at the same ground potential. Having everything at the same ground potential helps with lightning survival.

 

[MUTNAV]

Thanks.... Mostly got it. I ended up recalling things from the past and watching two you tubes about isolation transformers...

When working on simulators a long time ago, being young, I checked out an oscilloscope carts outlet strip and noticed that the ground wasn't connected, I was starting to fill out a hazard report when my supervisor spoke to me about how it was supposed to be that way, and I would confuse a lot of people.

Thanks for the help, nothing is ever as simple as it seems like it should be.

Thanks
Joel