[RE-wrenches] Classic 150 100 amp output breaker tripping?????

[boB at midnitesolar.com]

On 10/29/2015 5:02 PM, Jay wrote:
> boB,
>
> Is the OCP still being used and does it work in both directions?
>
> JAY
> Peltz power


Hi Jay.  Yes, the OCP you refer to is still there.  This particular OCP 
though is a hardware
fast OCP intended to protect the controller against large load surges on 
the battery
side of the controller...   This usually happens when battery cables are 
long and
the inverter(s) are connected electrically close to the controller, 
thereby drawing
huge amounts of current from the Classic than from the battery when the 
inverter
is turned on, charging its input capacitors or something with huge AC loads.

A good wiring practice these days is to, if convenient at least, wire 
the controller's
battery terminals close or right at the battery terminals.  Then, when 
an inverter
is either turned on and giving a momentary short circuit to the battery 
lines, that
current will come from the battery rather than the controller's electronics.

   Larger cables won't necessarily fix the problem due to battery cable 
inductance.

The 150s and 200s rarely need the OCP circuitry.  The 250 is the one the 
OCP was
really designed for but we put it into all of the controllers.

There is also over current protection going the other way but is not a 
microsecond
timed protection.  Plain old fast or slow ramping up surges like we're 
talking about is easy to
control, normally.

Breaker tripping like this is extremely rare, IF it is from this kind of 
current spikes due to
generator startup.   I would suggest to be safe and bring another 
controller up just in case.

Might be a bad controller but I just don't know without logging or 
observing it happening
with a scope and a current probe.  I've seen some very strange things 
happen.

boB



>
> Sent from my iPhone
>
>> On Oct 29, 2015, at 4:19 PM, "boB at midnitesolar.com" <boB at midnitesolar.com> wrote:
>>
>>
>> Larry, because these MPPT CC's are bi-directional (for efficiencies' sake), they can convert a large current
>> at the battery side to a smaller current at the PV side if not adjusted right.  Normally this is just taken
>> care of and reduced to a bare minimum by the controller watching the voltages and currents carefully.
>> It is technically possible though for things to not work exactly correctly.  I am not saying that this is
>> for sure happening, but it is possible.   The ramping up in battery voltage from the chargers should
>> be plenty slow enough for this not to be a problem but I am wildly speculating that this could happen
>> and cannot rule it out.  There may of course be something else completely different happening here
>> though.
>>
>> If CBI breakers are being used, these are known to be extremely fast at tripping when overloaded.
>>
>> Also, what, if any SPDs are connected to the system ?
>>
>> boB
>>
>>
>>> On 10/29/2015 2:45 PM, Starlight Solar Power Systems wrote:
>>> After the Magnum Inverter/charger samples incoming AC power, they have a slight delay before starting the charger. Then, they ramp up current slowly.
>>>
>>> Even so, how will any current from any other source pass through the breaker unless the Classic is presenting a load? I suppose something else could be wired through the breaker but I’m guessing Daniel would have looked at that.
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