Help With If To Set 25, 50 Or 100 Hz On Solar Controller

Discussion in 'Motorhome Chat' started by laneside, May 10, 2015.

  1. laneside

    laneside Funster

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    Help just put a 120 watt solar panel on and on the controller I have an option to set it at 25, 50 or 100Hz. Not a clue what the difference is

    Thanks
     
  2. Jaws

    Jaws Funster Life Member

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    WELLLL. Solar panels produce DC which is zero Hertz..
    Perhaps a picture or description of all the connections might help ?

    If all else fails it must be mains related so 50 Hz is what the UK and Europe uses
     
  3. laneside

    laneside Funster

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    Thanks Jaws I will post a picture
     
  4. laneside

    laneside Funster

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    sent a picture but to clarify, if possible, there are three settings to make

    I). Sealed battery, gel or flooded so that goes to sealed

    2) gives me a choice to send a percentage to cab battery

    3) is for Charging frequency and I have options of 25,50 or 100 Hz
     

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  5. funflair

    funflair Funster Life Member

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    I pinched this of the internet.

    If you're new to the idea of PWM then maybe it's not obvious.
    PWM = pulse width modulation.
    Basically, adjusting the time "on" and "off" of a series of pulses, to change the average.

    The solar charge controller monitors battery charge and regulates the current from the solar cells if there's too much. As long as the batteries are accepting full PV current without going over-voltage then the charge controller doesn't have to do much. When the voltage does come up to a specified level (say, abut 14.0V for a sealed lead-acid battery), then the charge controller will reduce the current flowing to the batteries. It does this by shutting off the PV current for a fraction of a second, then back on again, off, on, off and so on. If it pulses on half the time and off half the time, then the average current that flows is 1/2 of what it would be if the PV was hooked up straight to the battery. This is good, because by regulating down to 1/2 the current, the PV will not over-charge the battery, now that it's mostly charged, and the process of bulk charging or float charging can go on under control. So, on a day with full sun, straight on the panels, the current could be 100% if the charge controller detects that the battery is discharged, or 5% if it detects that the battery is full.

    How often pulses on or off is what's determined by the frequency switch. Your CC can pulse at 25/50/100 Hz; select whatever suits you; if you hear static on the kitchen radio, try a different setting. The charge regulation will happen no matter what frequency is set. On a Tristar, the PWM can be shut off entirely, but that's not recommended. They suggest you try other noise suppression devices before hampering the operation of the charge controller.

    Were your benefactors able to provide you with a user's / installation manual? I found it extremely helpful in tuning it just right (and avoiding mistakes) when setting up the Tristar I got a few years ago.
     
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  6. laneside

    laneside Funster

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    Thanks Funflair so reading that it does not matter as long as we are not getting interference on the television.
     
  7. Munchie

    Munchie Funster Life Member

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    Also from web


    and use DC light bulbs. No inverter to turn on and off, and no inverter loss.
    However, as most of the appliances in the USA require 110V/220V AC current, one can also attach an AC/DC inverter to provide the correct voltage. And, of course, people typically choose 60 HZ for USA and 50 HZ for Europe.

    You can run the system entirely "off grid" meaning that one has to generate 100% of one's own power needs, and setup one's own batteries for backup power. Or, one can run the system "on grid", essentially using the power company's system as a super-battery. One sends the surplus power to the grid, and can take extra power from the grid as needed. No batteries are required, although some systems use them for backup power.
     
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  8. Jaws

    Jaws Funster Life Member

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    PWM ??? As far as I am concerned that is comms related ( I should know LOL !! )
    But now it seems to have found a worthwhile application with solar panels and battery chargers
    So it would seem the faster the cycle rate


    Pulse-width modulation (PWM), or pulse-duration modulation (PDM), is a technique used to encode a message into a pulsing signal. It is a type of modulation. Although this modulation technique can be used to encode information for transmission, its main use is to allow the control of the power supplied to electrical devices, especially to inertial loads such as motors. In addition, PWM is one of the two principal algorithms used in photovoltaic solar battery chargers,[1] the other being MPPT.

    The average value of voltage (and current) fed to the load is controlled by turning the switch between supply and load on and off at a fast rate. The longer the switch is on compared to the off periods, the higher the total power supplied to the load.

    The PWM switching frequency has to be much higher than what would affect the load (the device that uses the power), which is to say that the resultant waveform perceived by the load must be as smooth as possible. Typically switching has to be done several times a minute in an electric stove, 120 Hz in a lamp dimmer, from few kilohertz (kHz) to tens of kHz for a motor drive and well into the tens or hundreds of kHz in audio amplifiers and computer power supplies.

    The term duty cycle describes the proportion of 'on' time to the regular interval or 'period' of time; a low duty cycle corresponds to low power, because the power is off for most of the time. Duty cycle is expressed in percent, 100% being fully on.

    The main advantage of PWM is that power loss in the switching devices is very low. When a switch is off there is practically no current, and when it is on and power is being transferred to the load, there is almost no voltage drop across the switch. Power loss, being the product of voltage and current, is thus in both cases close to zero. PWM also works well with digital controls, which, because of their on/off nature, can easily set the needed duty cycle.

    PWM has also been used in communication systems where its duty cycle has been used to convey information over a communications channel.
     
  9. laneside

    laneside Funster

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    Wow Jaws now you have me wishing that I had never asked but thank you incidently I have opted for middle ground at 50Hz unless you tell me different
     
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  10. Jaws

    Jaws Funster Life Member

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    I really do not think it will make too much difference in our temperate zone !! ;)
     
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