Overvoltage shutdown?

I have a Morningstar 45 and 4 L16s. My very basic Coleman inverter shuts down when the sun comes up. Its supposed to shut off at 16.5, but I metered 15.5 when it does shut down. How can I limit/regulate the voltage? Or is this even my problem?

Other inverters shut off at 15.5 so I'm not sure how they can function either.....

Comments

  • BB.BB. Super Moderators, Administrators Posts: 32,612 admin
    Re: Overvoltage shutdown?

    It sounds like either a MorningStar controller problem (which model of 45amp controller), bad electrical connection to the battery bank (loose, dirty, corroded connections/wiring), or possibly a "sulfated" battery (worn out battery, open cell, or stored discharged for weeks/months at a time--Is the battery charged and able to support the inverter when the charger is not charging?).

    When the battery is at 15.5 volts--is it bubbling a lot (H2 and O2 generation when battery is fully charged and being equalized)? What is the resting voltage of the battery (at night, no loads)?

    In general, the controller should never go above ~14.5 volts while charging a battery bank, except when the controller is equalizing (and it will charge the bank to 15-15.5 volts depending on programming--assuming this is a flooded cell battery bank).

    The MorningStar TS family of charge controllers do have an option for connecting remote battery voltage sense leads from the controller directly to the battery bus connections. If one of these leads is shorted/misconnected, it could be possible for the controller to read too low of battery voltage and over charge.

    Otherwise, does your battery charger connect directly to the battery common/bus points. And does the inverter also directly connect to the battery bank (and not at the output terminals of the charge controller to save on copper wire)? With remote sense and long wire run from controller to battery bank, it is possible for the controller to have >>14.5 volts at the controller and have 14.5 volts at the battery due to voltage drop.

    Those are the potential problems I can think of with the information given... Somebody else may add an obvious one I have forgotten. ;)

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • System2System2 Posts: 6,290 admin
    Re: Overvoltage shutdown?

    Awesome reply Bill, thanks.

    I know a little background is in order, but I'm at home full of meds because of a cold. Blech. When are we ever going to cure the common cold? It's common but not freindly

    Anyway. I have two 130 Koyceras powering the system. New everything. All was well for several days because (I'm guessing) the sun came out in force. I can run the inverter in the morning before sun hits. I did it yesterday. All of the sudden with the clear sun came the shut down. I have tried two of the same inverter so I know its not the one unit.....

    It has been wired per Morningstar/Midnight solar specs. I'm using a Midnight solar DC mini DC box as the wiring point/breaker box....

    Now, I do know the equalization is set to 15.5 for the LR16s', but it was on bulk/PWM when it shut down the times I tried to turn it on again.

    Seems to me a proper car voltage regualtor would cure this.....but dont mind me, I'm light headed....



    BB. wrote: »
    It sounds like either a MorningStar controller problem (which model of 45amp controller), bad electrical connection to the battery bank (loose, dirty, corroded connections/wiring), or possibly a "sulfated" battery (worn out battery, open cell, or stored discharged for weeks/months at a time--Is the battery charged and able to support the inverter when the charger is not charging?).

    When the battery is at 15.5 volts--is it bubbling a lot (H2 and O2 generation when battery is fully charged and being equalized)? What is the resting voltage of the battery (at night, no loads)?

    In general, the controller should never go above ~14.5 volts while charging a battery bank, except when the controller is equalizing (and it will charge the bank to 15-15.5 volts depending on programming--assuming this is a flooded cell battery bank).

    The MorningStar TS family of charge controllers do have an option for connecting remote battery voltage sense leads from the controller directly to the battery bus connections. If one of these leads is shorted/misconnected, it could be possible for the controller to read too low of battery voltage and over charge.

    Otherwise, does your battery charger connect directly to the battery common/bus points. And does the inverter also directly connect to the battery bank (and not at the output terminals of the charge controller to save on copper wire)? With remote sense and long wire run from controller to battery bank, it is possible for the controller to have >>14.5 volts at the controller and have 14.5 volts at the battery due to voltage drop.

    Those are the potential problems I can think of with the information given... Somebody else may add an obvious one I have forgotten. ;)

    -Bill
  • BB.BB. Super Moderators, Administrators Posts: 32,612 admin
    Re: Overvoltage shutdown?

    It does sound like the morning star either has a programing or hardware issue.

    Do you have an accurate digital volt meter to check various points in your wiring? Everything on the battery bus should be within a tenth of a volt of 14.4 volts when the charge controller is charging.

    If everywhere is 15.x volts, then I would look closely at the charge controller programing and call tech support and see if the controller is ok.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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