guess who bought a power jack inverter

[davidwillis]

I think I just fried my 8000 split phase power jack...  I was testing it to see if it would run some appliances.  I had a 1500 watt dual stove top burner on, and turned on a 1000 watt microwave.  It seemed to work for about 20 seconds, then it just shut off.  There was also a smell of smoke.  I shut it off and turned it back on, but it did not produce any power.  I have not taken it apart yet, but shouldn't they have some safety to prevent them from burning up it you load them too much?  I thought for sure it would run the two things, but I guess not...  Or was this just a faulty unit?

[oztules]

Its a dud. The 8000 will run those loads standing on it's head.
If it was running above 4-5kw and. more, it would beep for 12 seconds or thereabouts, and shut down from over load.
These things are o/load protected.... and even when they squark... you can bypass some of the current around the CT, and push them very hard and they still don't break..

Suspect faulty wiring in the power circuits... ie loose high current connections would be my first guess.. warranty if so.

They really are bullet proof if they are assembled properly.... yours was not from the sounds of it.

.........oztules

[davidwillis]

Thanks.  That is what I thought it should do.   Sounds like the first thing to do with these inverters are to take them apart and make sure there is nothing loose...?

[andymack]

the AeroSharp 2k5 transformer.  The labels shows manufacturer info.

2kVA, PRI : 230V  SEC: 250V  8.7A


How does this compare to the other transformers.

Thanks Oztules, I wouldn't have counted the turns.   Will now

[andymack]

Frackers


How much did you pay for the 48V 15kw boards?

(looks like the price is escalating)

[frackers]

How much did you pay for the 48V 15kw boards?

(looks like the price is escalating)

The price often looks good until you select the actual model you want and then you get a bit of a surprise! I've PM'ed the details.

[davidwillis]

I did some more testing with my inverter today.  I found that turning it on would not produce a voltage above 4 VAC, after a few seconds it would sound an alarm.

So I decided to take it apart to see what went wrong.  At first I could not see anything until I looked here:

[oztules]

Thats an amazing 8kw unit... it has the big power board in it, plenty of cooling... it really should have been a pretty good unit... much better parts than I have seen before in the 8kw  units... that should have been a ripper unit really. Bigger fet board, looks like their bigger tranny's, and dual cooling fans for them too.

I'm amazed it failed under such small loads.


............oztules

[davidwillis]

Yes, it is strange.  Any ideas on why those chips would break apart like that?  This has me a little worried.... Do you still think there was something wrong with this unit, or are there any other ideas why this would happen?

I had run other larger loads weeks earlier (a harbor freight 220v wire feed welder), and a few other things... do you think that could have damaged it?  Also I tried using the charger on it, but it simply would not work, and would end up giving me an alarm and shutting off, when I tried it (this was well before the burn down).

[oztules]

No. That configuration should be bullet proof. Are you sure this is only a 8kw unit.. the guts look more like 10kw..

Anyway, that fet destruction is normal for when you have a signal failure or fet failure. They are caught between the battery potential when they short... either they blow your battery fuse ( will happen if a few short together at the same time) or they will simply explode to get rid of the short.. fets always fail short, as you know what happens with a screwdriver across the batt terminals... well thats what the fets try to do too.

When one fails first, and explodes, then the next and the next follow in a cascade of pops, until there is no fet trying to short the battery any more. If they short together, then they have enough "fet legs" to present a massive low impedance, and then it may short your fuse if you have one.

Something was wrong with it. It should have saved itself from over load.... and the loads you describe would be trifling for it.

I have no idea of what split phase would do to the current ratings or how it works with the CT... we don't have that here... thats the only complication I can't guess at.
Usually it is something like loose battery cables, terminals even... then any other thing you have in the battery line that could cause sparking and inductive problems.... check the ribbon that connects the two boards together for broken wires, unplugged, and the opto isolators are plugged in properly

So no, I don't know how or why it failed.... as  I don't know how the current transformer sees the loads at 110v and 220v..... totally unknown at the moment.

The charger needs the frequency and voltage to be in range.. if you know it was in the right range ( grid perhaps), and it still would not sync, there was something wrong with the mother board.

..oztules

[davidwillis]

It may be a 10kw, but I ordered an 8kw, and it is not as big as the 10kw I have....  It sure seems like a luck of the draw as to what you really get...

Anyway, the only other thing I noticed inside was a small burn mark on the ground wire (you can see it in the second picture of my post).  Other than that nothing seems loose, and my batteries were connected well.

I know it sure would make a large spark when I would hook up the batteries, do you think it could have damaged them when I connected the power? 

[oztules]

No it is just the massive caps charging up very very quickly....they make an impressive splat don't they...

......oztules

[andymack]

Transformer strip down AeroSharp 2k5

Pri  230V  : Sec 250V

The secondary is 2 windings of 1.8mm dia in parallel.
There are 2 joins in each layer so I have 6 rolls of wire tha I pulled off.  The 2 windings are joined together at each join.

I had some problems sometimes with windings being caught under other windings so I may have goofed with the turn count, as their seems to be some variance between some of the counts. 

Layer A count is 239
Layer B count is 244

Its all good fun - until the shoulders start getting sore 

Andrew

[oztules]

Don't be shy with the pics..... ( the saddist in me likes to see others suffer like me...). The shoulders and back have new muscles in there,,, or old ones rejigged.... after this last Tranny. It is wound now, just the 14 turns of the primary to go.... easy when you say it quickly..hard if you try to do it neatly..... we'll see with mine.


It looks like you have a turn per volt or so close to it, so the inspire torroid is a bit bigger. The one I just wound seems to be 245v for 114 turns on a double core. Mine is now three layers of 1.6mm so (.8x.8x3.1417)x3 or  6mmsq.... if you use 2 x 1.8mm will be 5mmsq should be good for 5-6kw normal usage, as it will be well exposed for cooling.

I use a rule of thumb.... where the primary:secondary cross section area should be the same as the winding ratio.... so mine will be 8:1 turns ratio, so my primary should be around 8 times the 6mm or 50mmsq is close enough.... if we think the 50mmsq can handle 200a then the secondary 6mmsq will handle an honest  25 amps ... 6000watts.

Extension leads are 1.6mmsq for 15A 30 and 50 meters long.... on that metric, the 50mmsq can stand 50/1.6X16=500 amps for the same losses.... but only 10 meters of cable used. ( actually the 30 meter extension is really 60 meters for these purposes, as it is a 2 way trip for the heating.)... does that sound right??

I'd take your highest figure of 244, and calculate on 1v/turn for your core.    guessing your core is about 3000mmsq cross section.


...........oztules

[frackers]

Found some old toroids at a local scrap yard - sail cloth and shellac variety - but might be usable after a total rewind.

The label has the following details on it:

SECURR
CURRENT
TRANSFORMER
NZSS 2141

Type D06
Ratio 200/100/5
15 VA  Class S10
50Hz  No. 18781

I've only been able to measure with the windings still on.

150mm diameter
155mm high
14kg
1.5mm wire
0.14ohms resistance, centre tapped

Looking up tables based on 0.17 x 10-8 ohm.m it would appear there is about 15m of wire on them which will approximate to 40 turns.
Another table puts 1.5mm wire at 9.76ohm/1000m which would indicate about 70m which equates to 175 turns which is close to the 200 on the label!!
The centre tap allows access to the two separate windings.

Not sure if they will strip cleanly but I'll try and get an idea of how many turns there really is.

I'm tempted to put a few turns through of whatever I can find, put the existing winding via a 100w 'current limiter' bulb onto 240v and see what I get out. Would be pretty amazing if I could just put a few turns of primary on as there is a 45 gallon drum of these things available