EPever 3210an charge controller issue

Hi,

I have an Epever 3210an charge controller and with 2 identical 275 watt solar panels. I finally tried to connect the second one in parallel and get the message "rated voltage error". Separately the system works fine and both panels are putting out about 40 volts, when connected in parallel, it's the same, about 40-41 volts, but the charge controller flashes a warning or rated voltage error, which makes no sense. What, exactly is rated voltage error? The manual doesn't specify.

Any thoughts?

Thanks

Brian

Did you disconnect the battery at any time?

I did, before disconnecting the panel

circus said:

Did you disconnect the battery at any time?

Click to expand...

I did, before disconnecting the panel as the panel indicates.

Dirkpitt said:

I did, before disconnecting the panel as the panel indicates.

Click to expand...

That's what the panel indicates?

Dirkpitt said:

I did, before disconnecting the panel

Click to expand...

Not familiar with that charge controller, but don't most want the panels disconnected first and then connected last? Without a battery load, the controller may see too much voltage because you have more current available when in the panels are in parallel (and the voltage stays high). With only one panel,the controller may load it down more to an acceptable level.

circus said:

That's what the panel indicates?

Click to expand...

Yes, of course.

I suspect the controller is set to auto-sense battery voltage and got confused when the battery was disconnected. I would:

1. disconnect panels
2. disconnect battery
3. give it a moment
4. reconnect battery
5. manually set bank voltage as seen in this thread
6. reconnect the panels in parallel (or singly)

Theoretically you could wire them in series, but max voltage input at 25C is 92v and the unit is already at the edge of the spec for overpaneling with 550w (absolute maximum spec is 580w for 12v banks)

Dirkpitt said:

Yes, of course.

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It is highly unusual that a panel will indicate anything other than specs on the backside sticker. Hence the question.

Texas-Mark said:

Not familiar with that charge controller, but don't most want the panels disconnected first and then connected last? Without a battery load, the controller may see too much voltage because you have more current available when in the panels are in parallel (and the voltage stays high). With only one panel,the controller may load it down more to an acceptable level.

Click to expand...

The panels clearly indicate a caution to not disconnect under load. That makes sense to me, since high voltages are present.

fratermus said:

I suspect the controller is set to auto-sense battery voltage and got confused when the battery was disconnected. I would:

1. disconnect panels
2. disconnect battery
3. give it a moment
4. reconnect battery
5. manually set bank voltage as seen in this thread
6. reconnect the panels in parallel (or singly)

Theoretically you could wire them in series, but max voltage input at 25C is 92v and the unit is already at the edge of the spec for overpaneling with 550w (absolute maximum spec is 580w for 12v banks)

Click to expand...

I've got the controller set for 24 volts, which is what I'm running. The panels clearly indicate not disconnecting under load, which makes sense. Does anyone know what "rated voltage error" is indicating? The controller is capable of handling up to 100 volts, and both panels are reading about 40. I'm only trying to connect in parallel.
I'm running 24 volt and it capable of max PV array power of 1170 watts.

Dirkpitt said:

The panels clearly indicate a caution to not disconnect under load. That makes sense to me, since high voltages are present.

Click to expand...

I think you are misinterpreting that warning. I also think you problem, will be solved if you power things up in the order listed above. Also some charge controllers specifically warn not to connect the panels first, or else risk frying the controller. What does your controller manual say?

I've connected the panels first too without issue. But there is probably a reason they say not to. Just seems like common sense to connect the battery first to let the charge controller sense the batteries and their voltage. If the OPer is that concerned about what his panels say on a label, connect them at night. Problem solved.

Dirkpitt said:

The panels clearly indicate a caution to not disconnect under load. That makes sense to me, since high voltages are present.

Click to expand...

"Do not disconnect under load" is not equivalent to "disconnect battery first".

Dirkpitt said:

Does anyone know what "rated voltage error" is indicating?

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Have you googled epever rated voltage error? I have, it's how I found the thread I linked for you above. The solutions in both hits would be covered by the sequence given in post #8.

Dirkpitt said:

I've got the controller set for 24 volts, which is what I'm running. The panels clearly indicate not disconnecting under load, which makes sense. Does anyone know what "rated voltage error" is indicating? The controller is capable of handling up to 100 volts, and both panels are reading about 40. I'm only trying to connect in parallel.
I'm running 24 volt and it capable of max PV array power of 1170 watts.

Click to expand...

Not specific to the Epever

Following the proper connection/disconnection procedure is important for the following reasons.
The battery is what the controller uses for power, it's voltage is used to establish the nominal voltage in auto voltage select types, manual programmed types are self explanatory.

With either type of nominal voltage selection, the battery acts as a voltage regulator, if the battery is disconnected prior to disconnecting the array, there is no voltage regulation so it's likely the controller will have excessive voltage on its output terminals, which could produce an over voltage error, the error may require a cold reboot to clear the memory, in some cases the unit may be damaged.

The disconnect procedure is the reverse, disconnect the array first by means of a suitable DC rated circuit breaker or disconnect, then disconnect the battery. The reference to to not disconnect under load, is to prevent arcing which can damage terminals or MC4 connectors, in the absence of a DC disconnect a blanket over the modules could be used to cut any current flow should the battery be partially discharged.

Every time the correct procedure is followed, the controller will undergo a reboot, this is typical of most (all) charge controllers

The EPever units are not supposed to be connected to PV input without already being connected to the battery and should not be disconnected from the battery while still connected to the PV input.

As @Mcgivor said, you need a circuit breaker on the solar panel side since it is slightly risky/dangerous to disconnect the MC4 connectors under those loads. Note, It is also inadvisable to disconnect the screw terminals under load since it could arc and would leave you with two bare wires that would be easy to short or get shocked by.

@Dirkpitt did you get it working?