What is an inverter?

[AlanBeckett]

Why is it all in Americanese?

Alan

[Alan Douglas]

I'm not sure I follow, but I think you're saying that now you can plug the device (combination inverter and charger) in when you want it, but the previous electrician had it wired in all the time?

I assume the outlets on the device are always fed from the inverter, never directly from the power plug? If that's so, then there are two entirely separate functions in that device, a battery charger and an inverter. My original confusion was wondering how you could charge a battery with an inverter?

It's not all Americanese; it's a sort of hybrid, probably written by someone whose native language was neither American nor British.

[AlanBeckett]

I was thinking of the Drawing Alan. The use of the word 'Cord' and the drawing of the wall Plugs and Sockets.

Alan

[Nowhere-Man]

I was thinking of the Drawing Alan. The use of the word 'Cord' and the drawing of the wall Plugs and Sockets.

Alan

It's a below average translation from Chinese. It seems to have been made in Taiwan and then the instructions were translated by the best they had.

Actually I have a few Chinese friends and they tried teaching me the odd word in Mandarin. Not all translators are as good as my friends as the following may illustrate:

[Nowhere-Man]

I'm not sure I follow, but I think you're saying that now you can plug the device (combination inverter and charger) in when you want it, but the previous electrician had it wired in all the time?

I assume the outlets on the device are always fed from the inverter, never directly from the power plug?  If that's so, then there are two entirely separate functions in that device,  a battery charger and an inverter.   My original confusion was wondering how you could charge a battery with an inverter?

It's not all Americanese; it's a sort of hybrid, probably written by someone whose native language was neither American nor British.

Yes, you have understood correctly. Maybe my mistake was to just call it an inverter and assume I'd be understood. The more expensive units combine inverter and charger.

If you plug into mains supply, battery charger amps are only 10 so there's  no need for large cables to the batteries (just as a charger). However, if you switch off the mains supply to the unit or there was a power cut, you can use the unit as an inverter. It draws a steady 6 amps just being switched on and then draws current if you're using it to watch a movie. So cables need to be larger in that case. For example, once there was a power cut so I switched the inverter on. I plugged in a 50 watt TV/DVD but the low battery alarm sounded an hour or so later. My batteries were a bit low.

Because it uses inverter as well the battery cables need to be 100 amp as I said above.

Connecting permanently to shoreline was a bad idea. Normally there would be a selector switch from generator to shoreline to inverter. The guy who wired my boat was qualified but really you need marine electrical training and not house or buildings. There are very few courses for marine engineers in local areas. Areas like Brighton would be a better bet perhaps.

[Alan Douglas]

I was thinking of the Drawing Alan. The use of the word 'Cord' and the drawing of the wall Plugs and Sockets.

The drawing isn't proper Americanese either.  It would never be called a "home main socket" and the individual receptacles are drawn 90 degrees off.  From the National Electrical Code:
   
Singles and triples are very rare.  Duplex outlets can be installed in any orientation (there's a constant debate between "ground up" and "ground down") but the individual receptacles are always oriented per the drawing.

I didn't catch the "cord" usage since it seems normal to me.

[AlanBeckett]

I used to work for a subsiduary of Hubbell. Most of the ones I came across in the USofA seemed to be theirs.

Alan

[Nowhere-Man]

If anyone is interested, I recommend it's a good idea to learn about marine/boat engineering. I think the radio electronics also helps. There is plenty of work for boat electricians but it's a murky environment because very few marine electrical courses exist. So, you have a lot of household electricians wiring boats but the problem is this isn't such a good idea. They are likely to use domestic cable and, of course, DC and inverters need to be understood in depth.

Something I've been looking into over the last few days is alternator charging systems. I've noticed a large percentage of marine electrical people seem to view the positive and negative charging circuit as different. That is, current from the alternator + charging cable as opposed to the negative return. They figure if you put an ammeter in line with the B+ alternator you'll get the charging current but if you put the ammeter across the negative return to alternator case and battery, it will give the complete boat circuit amp draw. So I viewed it all the same as you would a radio:

Just like a transformer secondary, alternators produce AC voltage with is rectified by diodes. The alternator B+ ought to be the same as the DC ripple from a valve rectifier cathode used to rectify the secondary on a tube radio. Almost the same as with a radio, the alternator DC + goes to a lead acid battery bank (not a smoothing cap) but creates a charged supply. Current will of course be flowing through the charging cable and electron flow will leave the neg battery terminal, supply the boat circuit (pumps, DC lights) and return to the battery positive terminal (i.e. non conventional current flow).

I think it would be interesting for me to measure the amps from the B+ alternator and also the negative return to the alternator case but what I'd expect is for current to alter deeper into the circuit (the watts of appliances seem to me to be resistances in parallel.

Apparently it's now far more widespread to put ammeters in the negative charging line.

Inverters it seems have caused many problems with heavy currents.

[Herald1360]

And strictly speaking, a "generator" puts out DC while an "alternator" supplies AC.  However everyone talks about their "emergency generators" for household power, or "portable generators" to run tools a on a jobsite, so one just has to go with the flow.

Interesting.....

I thought generator was a general term for a machine that generates electricity of whatever flavour. Specific dc machines being dynamos and ac machines, alternators.

I suspect there may also be a touch of British vs American terminology clouding the issue as well.

[Alan Douglas]

Could be. I haven't seen "dynamo" used here in decades.