Inverter(s) tripping

[BritishPete]

Now technically I included a time base (day) so this now becomes a measurement of total power (energy consumed in 24 hours). 180 watts per day or 180Whrs per day = same thing.

180 watts average per day is 4.3 kilowatt-hours per day. This is a pretty common question in PV - "how many kilowatt-hours will I need if I use 100 watts a day average?" 100 watts is power; the answer they want is 2.4 kilowatt-hours per day, which is a measure of energy.[/QUOTE]

I strongly disagree with you. WATT is a measurement of power in a given time frame. Watt hour or Watt day is a measurement of total work done.

So a circujit consumes 15 amps per day at 12 volts; How many watts are used?

I guess my engineering course (EE and BBC) was different to yours.

[john p]

Britishpete if your chest freezer as a fridge that uses 180whr really uses 4.3 kilowatthrs a day im happy im not paying your electricity bill
. if you are running it off grid wow thats a LOT of battery capacity needed.
I think your engineering degree is for plumbing?dentistry?mountain bike construction?

[BritishPete]

britishpete if your chest freezer as a fridge that uses 180whr really uses 4.3 kilowatthrs a day im happy im not paying your electricity bill
. If you are running it off grid wow thats a lot of battery capacity needed.
I think your engineering degree is for plumbing?dentistry?mountain bike construction?

do you feel a need to be so rude?

[Sunking]

I strongly disagree with you. WATT is a measurement of power in a given time frame. Watt hour or Watt day is a measurement of total work done.

So a circujit consumes 15 amps per day at 12 volts; How many watts are used?

I guess my engineering course (EE and BBC) was different to yours.

This proves you are a fraud and lying through your teeth. You do not even know basic electrical principles taught on Day 1 of school. No engineering student would even make that mistake. So therefore you are a FRAUD.

[billvon]

I strongly disagree with you. WATT is a measurement of power in a given time frame.

No, there's no time frame involved; it's a unit of power, and there is no time aspect to power. A watt is a watt, and it's a watt whether it is there for a picosecond or a century.

Some common units of power:

Horsepower
Watt (kilowatt, milliwatt etc)
dBm (measurement of RF power)

Watt hour or Watt day is a measurement of total work done.

That's a measurement of total energy. Energy can be used to do work.

Some common units of energy:

Joule
Watt-second (or hour, or megawatt hour etc)
Calories
BTU

So a circujit consumes 15 amps per day at 12 volts; How many watts are used?

It uses (15*12) = 180 watts. If it is on continuously it uses (180*24)=4.3 kilowatt-hours per day.

[Sunking]

No, there's no time frame involved; it's a unit of power, and there is no time aspect to power. A watt is a watt, and it's a watt whether it is there for a picosecond or a century.

Some common units of power:

Horsepower
Watt (kilowatt, milliwatt etc)
dBm (measurement of RF power)



That's a measurement of total energy. Energy can be used to do work.

Some common units of energy:

Joule
Watt-second (or hour, or megawatt hour etc)
Calories
BTU



It uses (15*12) = 180 watts. If it is on continuously it uses (180*24)=4.3 kilowatt-hours per day.

My friend you are wasting your time. He claims to be an EE with experience. A first year student would have that burned into their memory or they fail Electricity 101, and kicked out of school. That ought to tell you something about him real quick.

[BritishPete]

No, there's no time frame involved; it's a unit of power, and there is no time aspect to power. A watt is a watt, and it's a watt whether it is there for a picosecond or a century.

Some common units of power:

Horsepower
Watt (kilowatt, milliwatt etc)
dBm (measurement of RF power)



That's a measurement of total energy. Energy can be used to do work.

Some common units of energy:

Joule
Watt-second (or hour, or megawatt hour etc)
Calories
BTU



It uses (15*12) = 180 watts. If it is on continuously it uses (180*24)=4.3 kilowatt-hours per day.

"Watt-second (or hour, or megawatt hour etc)"

So second or hour is OK but not DAY Huh! I think some are splitting the superlative here!

[Sunking]

So second or hour is OK but not DAY Huh! I think some are splitting the superlative here!

No spiting superealtive, just one who is clueless. There is no such thing as a 180 watt/day

[BritishPete]

So back to topic.

The diode works great for me, saves me many $$$ in changing out my inverters and wastes absolutely zero power that would not be wasted anyway. In fact it GAINS power because the batteries can be charged at a higher rate.

[Sunking]

So back to topic.

The diode works great for me, saves me many $$$ in changing out my inverters and wastes absolutely zero power that would not be wasted anyway.

Yes back on topic please. Since when did a diode quit consuming power. Please tell us so we will all know.

[BritishPete]

Yes back on topic please. Since when did a diode quit consuming power. Please tell us so we will all know.

I shall; When my PV array is capable of generating say 80 amps ant 14.8V but is only charging the batteries at 20 amps because they are 80% full where is the 60 amps going? Answer WASTED. Now install a diode that will permit me to increase charge current to 30 amps (at say 15.2V) without tripping the inverters and I have GAINED 10 x 15.2 = 152 watts not wasted.
It is not rocket science but some would have us believe it is.

Remember I have 1000AH of battery so no need to pretend I will fry them at 30 amp charge.

Also all of this is done with automatic battery temperture monitoring by my MPX 80 which will reduce charge current if needed.

[Sunking]

I shall; When my PV array is capable of generating say 80 amps ant 14.8V but is only charging the batteries at 20 amps because they are 80% full where is the 60 amps going? Answer WASTED. Now install a diode that will permit me to increase charge current to 30 amps (at say 15.2V) without tripping the inverters and I have GAINED 10 x 15.2 = 152 watts not wasted.
It is not rocket science but some would have us believe it is.

Remember I have 1000AH of battery so no need to pretend I will fry them at 30 amp charge.

I was hoping you would step into that trap. You are too easy. I gave you rope and you hung yourself with it. Tell you what; I will let others tell you that you do not know what your are talking about. I will give you a clue, what does 30 amps x .7 volts =

[BritishPete]

Read all of my posts and you shall see.

[BritishPete]

I was hoping you would step into that trap. You are too easy. I gave you rope and you hung yourself with it. Tell you what; I will let others tell you that you do not know what your are talking about. I will give you a clue, what does 30 amps x .7 volts =

It doesn't matter! it is still coming out of the otherwise wasted 60 amps!!! and in any case 30 x -7 = 21 watts not the 152 watts gained. Where did you learn math?

So I gained 152-21 watts big deal. But you are still missing as MAJOR point the diode ONLY goes to the inverters NOT the batteries so no load no waste.

[billvon]

So back to topic.

The diode works great for me, saves me many $$$ in changing out my inverters and wastes absolutely zero power that would not be wasted anyway. In fact it GAINS power because the batteries can be charged at a higher rate.

Well, it wastes (.7 * DC current draw * hours of draw) watt-hours per day. If you have the power to spare, great, then it's not an issue.

If not, here's another option:PowerLDO.jpg

This is effectively a very high power LDO. It will limit voltage to 15 volts (to whatever you set it to actually.) It works similarly to the diode in that it adds a voltage drop to the circuit, but doesn't need to be switched in and out, and thus will always dissipate the least possible power while keeping the inverter's voltage below 15 volts. It is good to 360 amps, and the NFET's can be paralleled to increase that as high as you like.

Parts are about $10.