Energy Matters Forums

[APR]

As a side note, if i cant source copper bar locally, any ideas where I could get some and have it shipped at a reasonable price?

If you have access to a press, cut an adequate sized and thickness copper pipe into the trquired lengths, flatten it, drill it, and tidy up the ends.

19mm OD copper pipe flattens out to around 30mm. A common wall thickness that I have found in scrap yards is 1.2mm, so a cross sectional area when flattened is 2.4mm X 30mm, or 72mm^2. Alternately, check out seller "offcuts.galore" on eBay....

http://www.ebay.com.au/itm/Copper-Buzz- ... 2101728081

[new to solar power]

As a side note, if i cant source copper bar locally, any ideas where I could get some and have it shipped at a reasonable price?

I went to Essential Energy Depot in my area and asked the store man for some copper bus bar and he gave me what I needed and a bit extra in case I made a mistake.
I have a Kemppi Master !50A inverter welder that I use for stick welding ( an older type 1996 model which is very reliable,)
Also I have a Lincoln SP170A mig welder with no problems.
In my workshop I have a Uni Mig 250A Mig welder. This one is a rectifier type and I limit it to 25A from the 240v supply, the inverter is working at 100% capacity.
Working the 9 inch Angle grinder, 14 inch cut off machine hard, they work fine too.
I cannot notice any difference using these welders between mains supply and inverter supply.
We are totally off grid.

[davidg]

I use fluro lights inside, and they flicker in a very rapid way and very intensly when using the weldcorp. I have never seen any flicker like it. This makes me believe that the waveform is to blame.

Sounds like Harmonics.

As a side note, if i cant source copper bar locally, any ideas where I could get some and have it shipped at a reasonable price?

Copper pipe, just ensure you make the area large enough of the interconnects between batteries.

[offgridQLD]

I have been dealing with the same issues.

I run two different welders offgrid from inverters. One main unit is a 200A AC/DC invertrer tig (that is also a Arc welder) the other is a smaller 140A inverter tig (also a arc welder) I also run a 60A plasma cutter to.

The issue you are having like you say isn't that the load is to large for the inverter. It's the kind of load. When manufactures design there equipment they are counting on most people will be using it powered from the grid. The grid has a huge ability to absorb things that can create problems with battery powered inverters.

Harmonics and all kinds of feedback issues can have your inverter doing all kinds of crazy things. From experience even a tiny adjustable electronics rework heat gun that only has a 250w element can result in a 85kg 6000w continues high quality inverter shuddering and carrying on (making all the lights flickerin the house and fridge make strange noises) It's just the feedback from the device.

No issues on the grid as its just way to massive to have a effect on it.


To often my wife would come up to the workshop and say the fridge is making strange noises. I would look up from the welding table and think.... hmmm all the dials on the front of my welder that are used to chop up the output and make it pulse and tweek the frequancy output in every possible way do result in a great weld but are hell on my inverter and are feeding back and are having a similar effect on the house inverters nice stable clean output.

Another good one was when my wife mentioned she could hear the rhythmic sound of my 3cyl 16A air compressor coming through the vacuum cleaner when she was using it in the house:lol:

So the way I fixed the issue was to install a separate inverter for the workshop. Now the workshop is completely isolated from the house and all my nasty loads from welders and induction motors have zero effect on the house. Also its great not having to think befor I crank up a 4000w welder. I wonder if my wife is vacuuming with say the dishwasher on and a few other loads at 3000 - 4000w in the house. I can just go full tilt and If i trip the inverter it has no impact on the house.

The dedicated workshop inverter is just a inexpensive inverter as I think for it's application top shelf quality isn't needed. It has a 4000w continuous rating and 8000w spike loading. Haven't trip it out yet.

All the gentle clean demestic house loads from appliances run through the selectronic inverter and it has a easy life now.

Kurt

[notanothername]

Thanks for all the recommendations guys.
I got to the scrap yard today and bought a roll of copper bar. 3mm x 25mm so 75mm^2 so that should be fine for the interconnects. He had 8 kilos for $95 but he said it had sat for too long so I got it all for $60

The missus gave me the ok to spend for the unimig 165. all I have to do now is find one.. xD.

[notanothername]

Okay everyone.

For starters, thank you all.

I have the copper and will be replacing the interconnects this week. Making the holes and insulation now.

I purchased a UniMig RazorWeld 175amp online from ebay. Cost 740 with a bonus helmet.

Tested it out at the block. PERFECT

Slight blink when starting run and very slight feedback flicker when welding arc. So slight, you wouldn't notice if you were not looking for it.

Great advice guys.

[Gordon-Loomberah]

Great to hear you have a good result with the welder

Regarding working on the batteries when you put the new Copper bars on, I find it useful to place a heavy sheet of cardboard, or other similarly good insulator, over the top of all the batteries, and particularly the exposed terminals & connectors, other than the one you are working on. It gives you some peace of mind that if you accidentally drop an uninsulated spanner, you wont have a nasty explosion of liquid metal to deal with
I also have the handles of the Allen key and shifting spanner that I use for the battery connectors wrapped in a couple of layers of insulation tape to guard against accidental short circuits. You can get thousands of amps out of a big Lead-acid battery, and significantly more with a Lithium battery

[notanothername]

Thanks for the tips Gordon.

I have already made insulated spanners with heatshrink and Ill be putting heatshrink on the bars. Battery safety is a big thing to me. Ive taught my kids well. Not even allowed to walk within a meter of the batteries with any conducting material.