Hugh, I always explore more useful things on your page – thanks a lot!
We have just fired up our system 2 days ago. (Outback Inverter and FM80 etc.) and I’m trying my options for heating my hot water with ‘load diversion’. (The house has not been built yet, and I still have to make a decision on the Hot Water Cylinder and its elements and where to place them) As I have those AUX outputs on my FM80 I hope to be able to use this and not have to purchase a Tristar.
The option PWM with a SSR has the usual side effect of flickering lights.
Does this ‘phase angle SSR’ above eliminate this side effects? How will this react on my FM80? If the Tristar spits out a similar PWM than the FM80 it should work as well…, no?
I got 2 connections on the FM80 I guess one would be ‘TS O/P’ the other one ‘GND’, how about V+? My battery voltage is 48V.
The 2 resistors you have marked to be 2kR, this means 2kohm, right?
…now it starts to be interesting, where is my soldering iron?.. yeah
Cheers
Hi Ben,
I assume this would work with the pwm output of the FM80 as well as it does with the output of the tristar. YOu need to connect 48VDC to V+ and the zener diode circuit will reduce this to a safe level to power the SSR. Google the SSR crydom mcpc for a data sheet for that but I think the limit is around 30VDC. The signal is 0-10V but I find that if it reaches the full 10V (100%) level sometimes it turns off (!) so I arrange things so it doesn’t quite manage to reach that. There is no flicker but you may here buzzings here and there. Don’t use an air heater with a coil of wire. Yes 2 kilo-ohms.
have fun! HUgh
Great!
I’ll get this started and I will let you know my findings.
But we need to get this house built before we can have some midterm results…..
Thanks again!
I will soon be in Florida, so shipping will be easy. Do you know of an equivalent to TP Fay in North America?
Good news on power to the heater, I was concerned it would be 1/36*14V=useless (not that 28 watts is that great either). But continuing on that example, as the batteries get more charged, presumably it would go up to the full 12 amps, so 12*14=168Watts, which is beginning to get reasonable. In my case I have a small 6 gallon tank, the cold water temperature is already 25C and the wind turbine is more powerful turbine (peak output 25 amps at 14V, 18 amps at 20 knot winds), so it looks like I will get plenty of hot water. In fact, I may have to consider a way to short the wind turbine when the water gets hot! Does all this make sense to you?
Thanks once again for your time,
Dov
http://www.hydrogenappliances.com/hotwater.html
Yes you can short the turbine when the water is hot – that makes sense – or when the battery voltage goes too high. A relay driver is ideal for this.
Hugh, You’ve been enormously helpful, thanks. As you wrote in one of your other blogs describing another circuit, “Some knowledge of electronics will be required to build one of these circuits.” I don’t have that knowledge, so I won’t go down the path of building circuits, and will abandon this line of thinking. However, I did just come across your reference to TPFay, so I’ll talk to them about getting a 12V element for my water heater despite the manufacturer not making one.
One final question for you, on PWM; You wrote in one of your blogs “Don’t worry about your 12 amp dump load draining the battery. Even if the wind turbine is only producing 2 amps and the battery is full, the Tristar will only divert those 2 amps into the heater, and not more. It does this by switching the heater on for only 1/6 of the time.” I understand this, but I am wondering what this does to the heat output of the heater. Is it full momentary heat for 1/6 of the time, and none for 5/6 of the time (thus averaging to 1/6 of the rated heat), OR, does heater see an average current of 1/6 of its rated 12amps, thus resulting in 1/36 of the heat (using the formula P=IIR, reducing I by 1/6 gives power reduced by 1/36).
Thanks again, Dov
Yeah the best idea is to get a suitable heater from tp fay. I should have said that before but for all I knew you were in barbados.
Be aware that it will operate at 14 volts and not really 12 volts although it makes very little difference. If the heater is on 1/6 of the time it is full on and so the usual ohms law equation of voltage and current and resistance do not apply. Current is 2 amps average but voltage is the full 14 volts, so the power to the heater is 28 watts.
Hugh, I always explore more useful things on your page – thanks a lot!
We have just fired up our system 2 days ago. (Outback Inverter and FM80 etc.) and I’m trying my options for heating my hot water with ‘load diversion’. (The house has not been built yet, and I still have to make a decision on the Hot Water Cylinder and its elements and where to place them) As I have those AUX outputs on my FM80 I hope to be able to use this and not have to purchase a Tristar.
The option PWM with a SSR has the usual side effect of flickering lights.
Does this ‘phase angle SSR’ above eliminate this side effects? How will this react on my FM80? If the Tristar spits out a similar PWM than the FM80 it should work as well…, no?
I got 2 connections on the FM80 I guess one would be ‘TS O/P’ the other one ‘GND’, how about V+? My battery voltage is 48V.
The 2 resistors you have marked to be 2kR, this means 2kohm, right?
…now it starts to be interesting, where is my soldering iron?.. yeah
Cheers
Hi Ben,
I assume this would work with the pwm output of the FM80 as well as it does with the output of the tristar. YOu need to connect 48VDC to V+ and the zener diode circuit will reduce this to a safe level to power the SSR. Google the SSR crydom mcpc for a data sheet for that but I think the limit is around 30VDC. The signal is 0-10V but I find that if it reaches the full 10V (100%) level sometimes it turns off (!) so I arrange things so it doesn’t quite manage to reach that. There is no flicker but you may here buzzings here and there. Don’t use an air heater with a coil of wire. Yes 2 kilo-ohms.
have fun! HUgh
Great!
I’ll get this started and I will let you know my findings.
But we need to get this house built before we can have some midterm results…..
Thanks again!
Thanks Hugh!
I will soon be in Florida, so shipping will be easy. Do you know of an equivalent to TP Fay in North America?
Good news on power to the heater, I was concerned it would be 1/36*14V=useless (not that 28 watts is that great either). But continuing on that example, as the batteries get more charged, presumably it would go up to the full 12 amps, so 12*14=168Watts, which is beginning to get reasonable. In my case I have a small 6 gallon tank, the cold water temperature is already 25C and the wind turbine is more powerful turbine (peak output 25 amps at 14V, 18 amps at 20 knot winds), so it looks like I will get plenty of hot water. In fact, I may have to consider a way to short the wind turbine when the water gets hot! Does all this make sense to you?
Thanks once again for your time,
Dov
http://www.hydrogenappliances.com/hotwater.html
Yes you can short the turbine when the water is hot – that makes sense – or when the battery voltage goes too high. A relay driver is ideal for this.
Hugh, You’ve been enormously helpful, thanks. As you wrote in one of your other blogs describing another circuit, “Some knowledge of electronics will be required to build one of these circuits.” I don’t have that knowledge, so I won’t go down the path of building circuits, and will abandon this line of thinking. However, I did just come across your reference to TPFay, so I’ll talk to them about getting a 12V element for my water heater despite the manufacturer not making one.
One final question for you, on PWM; You wrote in one of your blogs “Don’t worry about your 12 amp dump load draining the battery. Even if the wind turbine is only producing 2 amps and the battery is full, the Tristar will only divert those 2 amps into the heater, and not more. It does this by switching the heater on for only 1/6 of the time.” I understand this, but I am wondering what this does to the heat output of the heater. Is it full momentary heat for 1/6 of the time, and none for 5/6 of the time (thus averaging to 1/6 of the rated heat), OR, does heater see an average current of 1/6 of its rated 12amps, thus resulting in 1/36 of the heat (using the formula P=IIR, reducing I by 1/6 gives power reduced by 1/36).
Thanks again, Dov
Yeah the best idea is to get a suitable heater from tp fay. I should have said that before but for all I knew you were in barbados.
Be aware that it will operate at 14 volts and not really 12 volts although it makes very little difference. If the heater is on 1/6 of the time it is full on and so the usual ohms law equation of voltage and current and resistance do not apply. Current is 2 amps average but voltage is the full 14 volts, so the power to the heater is 28 watts.