Mon, 06 Jun 2005 06:22:43 GMT
Richard sayed:
Whoops, I may have not made myself clear. I meant I was going to ground the case of the inverter.
I was aware of the dangers about tying in the neutral to ground plus I didn't want to open the case
and void the warranty either! heheh...
Interestingly, I put one of those yellow outlet testers from GB into one of the outlets of the
inverter and all the status lights came on. Of course there's nothing in the manual of the tester
that states what that means.
G'day Richard, I have been following along with interest, as your question is one I
asked of a number of Electrical Authorities here in Australia back in 1990, when I
was heavily committed to RE both ideally and financially.
I have given up contributing here since arseholes alsem GymmyB0b/JP BENGI made the
scene look like a rubbish tip of knowledge.
This is my two bobs worth on your question.
Interestingly enough you provide part of the answer in your "yellow tester"
statement.
Essentially the answer is one of "referencing".
From a teaching perspective, if you take the ideal circuit as being a total Path of
"supply and return" with energy delivered/consumed being through the whole of the
resistive/inductive circuit, then an alternative Path can only be formed when one
makes a lower resistive circuit across the supply.
IE: An inverter generated circuit can only work across the output of the electronics.
Reference that to anything else and the circuit just will not work. The inverter
shuts down.
Its a far safer system than even the "isolation tranny" of the sixties.
Hence your answer lies in treating every situation as you would a "Double Insulated"
instance. IE: Ground nothing.
Make sure your appliances/tools etc are always in good order electrically as to
insulation integrity and circuit/path continuity. A point to note here is that it is
quintessentially safe to ensure the active/high potential/hot wire is always
switched.
It is the case that some European and USA manufactured devices do switch the "low
side" within device control circuitry. Vending machines are just one I can think of
immediately.
On the issue of grounding I found both in field practice and from bench testing that
applying grounding to the case of an inverter then tied the Negative of the
battery/battery bank to a separate referencing medium to that which the inverter
output was referenced. That was seen to cause instances of circulating currents being
setup between earthed devices that contained electrical elements which may
occasionally find Ground. An example is the wetting of heater bars in a "auto-defrost
fridge" during the defrost cycle, the man who turned the light on inside the fridge,
another.
The end result varied from the noticeable "tingle" felt from the frame of the fridge
to a complete inverter shutdown, with all the variables in between. Again, not
grounding the Vehicle/Bank eliminated these problems.
All of my work on this topic was done whilst dealing Solartronic Inverters, a West
Australian Company that was later absorbed by some Corporate juganaut. Their Inverter
product (Australian Designed) was an excellent performer with high efficiency
returns, well ahead of any local competitor and well in front of the imported sine
wave Siemens product.
An excellent source of products and information of that time remains today at the
Rainbow Power Site. Well worth an email or two.
http://www.rpc.com.au/
Their catalog/book [PRN-006] is well worth the few bucks.
Hope that helps you some
/me gives mll a wave
[I theenk the GB brat is pissin' in his pants at the moment <BFEG>]
Lektr0n Nuis
