Inverter(s) tripping

[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]

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.

[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]

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.

[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?

[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]

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.

[Mike90250]

....180 watts average per day is 4.3 kilowatt-hours per day. ...

Darn big freexer to pull that much ! I could run 4, full size fridges for that power.

[billvon]

Ref yourt last, this is what I wrote;

Convert a chest freezer! I did and use only 180W per day average

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. [/QUOTE]

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.

[Sunking]

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.

I rest my case you do not know the difference between watts and watt hours. They are not the same thing.

Watts = Power = Voltage x Amps
Watt Hours = Energy Consumed or delivered = Watts X Hours = Volts x Amps x Hours

Huge difference.

[BritishPete]

Ref yourt last, this is what I wrote;

Convert a chest freezer! I did and use only 180W per day average.

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.

Without a DAY or HOUR or whatever other time base I agree I would have been incorrect.

[BritishPete]

Britishpete really a diode is not the answer to solving the overvoltage problem, The losses are great unless you are going to be manually switching it in and out of circuit. That is a pain.And you are making the inverter draw more current than usual .Lower input voltage must draw more current than higher voltage for a given output wattage.

Think about getting an adjustable controller. then set it to 15v. its a cheaper solution than going to 24v ,unless you intend to vastly increase the system size. 12v has advantages. there are more easily obtainable devices than 24v ones.

The only time I think people should have a diode in the input side of the inverter is to fool the inverter to shut down sooner than they usually do. Nearly all 12v inverters have a low voltage shutdown of between 10.5 and 11v . Far to low to save the battery. But this really is a design fault of the inverter .While it would help that problem ,it creates its own problems.

Also remember what Sunking said. Dont ever give a statement like "it uses 180w". You always need to use watt hrs. ie 180whr. Think about how your grid meter reads power ie 1080kwh..

Actually I have a controller with multiple variable user parameters including shut down at user defined voltage (mine is set to 11.8V with reconnect at 12.1V) BUT I think you are missing my point; In order to fully charge the batteries within sunlight hours I need more than 14.8 volts once a week. There is no jumping up and down I just put the diode in circuit for 2 hours once a week. Losses are really irrelevant as the power would otherwise not be flowing to the batteries anyway once they are on absorb for an hour or two. So I wait until charging current falls off to about 20 amps (on a 1000AH bank) then increase voltage to increase charge amps to 30A (decreasing) for the last 2 hours.

For me it works perfectly, and is very little hassle.

[john p]

Britishpete really a diode is not the answer to solving the overvoltage problem, The losses are great unless you are going to be manually switching it in and out of circuit. That is a pain.And you are making the inverter draw more current than usual .Lower input voltage must draw more current than higher voltage for a given output wattage.

Think about getting an adjustable controller. then set it to 15v. its a cheaper solution than going to 24v ,unless you intend to vastly increase the system size. 12v has advantages. there are more easily obtainable devices than 24v ones.

The only time I think people should have a diode in the input side of the inverter is to fool the inverter to shut down sooner than they usually do. Nearly all 12v inverters have a low voltage shutdown of between 10.5 and 11v . Far to low to save the battery. But this really is a design fault of the inverter .While it would help that problem ,it creates its own problems.

Also remember what Sunking said. Dont ever give a statement like "it uses 180w". You always need to use watt hrs. ie 180whr. Think about how your grid meter reads power ie 1080kwh..

[BritishPete]

Good to know, of course I am stuck with mine now but one day I might just upgrade to a 24V or 48V system, that would be the time.

[Sunking]

Anyway your loss I had much to offer but cannot deal with arrogance.

It is not arrogance, it is experience. Between John P and myself we have over 70 years combined electrical design and technical experience. Throw Mike, Russ, and Rich into the equation and we have over 100+ years of experience

So far you have not added any value. You lack basic knowledge and design concepts of solar power systems. So far you have given bad advice which is why you are rebutted. Those with experience are not going to allow you to get away with it. One example is you do not know the difference between a watt and watt hour., or how to calculate either value. watts and watt hours are two of the most important specs in an electrical system and if you do not completely understand that you have no biz giving advice.