Magnum MS-PAE Not Limiting Generator Current Correctly

mcnutt13579
mcnutt13579 Registered Users Posts: 112 ✭✭✭
edited December 2021 in Off Grid Solar & Battery Systems #1
Single Magnum MS-PAE system, 24 volts, on a Midnite compact panel, the kind that swings with the inverter on it.  ME-ARC to control.  We are a professional service co. serving the customer.
The 30 amp generator input breaker tripped after some weeks of running fine.
Batt charge rate set to 100%, this is an enormous battery.
Setup: 03A was set to default of 30A. 
Decreased it to 23A for good headroom and then checked gen input current.  Still was around 30-31A.  Eventually had to decrease it to 14A in order to show 24A on the AC input meter screen.  At this point battery amps were around 92ADC where they were well over 100A when consuming 30A input.
Outgoing loads shown about 1A during all this time.
It seems like the inverter is not controlling its battery input properly.  Any idea what might be wrong here?
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,634 admin
    edited December 2021 #2
    From the manual;

    https://www.solar-electric.com/lib/wind-sun/Magnum-MS-PAE-Manual.pdf
    Wiring the Inverter AC Input (from the main panel) 2.

    a) For a 120/240 VAC input: Connect the hot 1 wire (black) from the main panel’s dedicated dual-pole circuit breaker to the inverter’s HOT 1 IN terminal, and then connect the hot 2 wire (red) from the main panel’s dual-pole circuit breaker to the inverter’s AC HOT 2 IN terminal.

    b) For a 120 VAC input: Connect the hot wire (black) from the main panel’s dedicated dualpole circuit breaker to the inverter’s AC HOT 1 IN or AC HOT 2 IN terminal, but NOT both or damage may occur.

    CAUTION: If using only a 120 VAC input source, you will need to turn the charge rate down to 50% using a remote control (i.e., ME-RC, ME-ARC or ME-RTR). This prevents the inverter from overheating because of a transformer imbalance when charging the battery bank and running loads from both the HOT 1 and HOT 2 outputs.
    Just a quick bit of poking around... Is your "charge rate" set correctly?

    I am not sure--But the rate of charge assumes 120/240 Split Phase power... If you only power with 120 VAC, then you need to scale the charging current by 1/2 ??? 

    Does any of this make sense to you? I understand the 120 VAC input is only 1/2 the power available from the 240 VAC input (1/2 the transformer input winding used, 1/2 the power "allowed" through the 120 VAC inpu--only can only supply 1/2 the rated charging current).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • mcnutt13579
    mcnutt13579 Registered Users Posts: 112 ✭✭✭
    #3
    Charge rate is set to 100%.  The battery can handle it.

    It is being powered by a 120/240 split phase genset with plenty of power.

    But this is an interesting idea: I wonder if one phase is missing somewhere between the generator and inverter.  Will check with an amp clamp when I get back there.
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  • mcnutt13579
    mcnutt13579 Registered Users Posts: 112 ✭✭✭
    #4
    I came across another system new to me with 3 MS-PAE units in parallel. Current limiting on this one also behaves strangely, just have to change the setpoint in the ME-RTR and measure with an amp clamp what actually happened until you get the number you want. Not confidence-inspiring.
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