Clipper using Classic AUX1

[dgd]

I was just reviewing my two Classics' setup and  the Classic connected to my AC Clipper uses AUX2  set to Clipper Control.
Everything works as it should.   However, the Classic AUX1 is also able to be set to Clipper Control. I assume this means that AUX1 could be wired to the Clipper instead of AUX2?

Since AUX1 does not have hardware PWM output then I also assume that the Clipper Control via AUX1 would not be able to gradually introduce the Clipper's resistors into the AC path from the turbine?  So what would actually happen? Would AUX1 just totally switch in the resistors or does the Classic firmware at least do some slower PWMing using AUX1?  And can the relay on AUX1 be jumpered out so its not used if slow PWMing is possible?

I'm asking this 'cos I'd like to start wizzbanging...

dgd

[dgd]

...so has anyone with a Clipper used the Classic's AUX1 set to Clipper Control to connect to the AUX input of  the Clipper?

[boB]

Aux 1 will also work to tell the Clipper what to do.  Aux 2 has a faster PWM than Aux 1 but Aux 1 may be fast enough.

Also, Clipper mode in Aux 1 does not have an adjustable headroom.  The headroom  is set for +5.0 volts above the PV voltage
that it had when it went from MPPT to Absorb, Float or EQ.  The Delay and Hold time is not adjustable either but it
is either On or Off.  When the Classic goes to MPPT from the constant voltage stage, the Aux 1 output will go Off
again, disabling the Clipper (except for the Clipper's hardware maximum voltage set point adjustment pot)
This is pretty fast reacting but may or may not work good for you.

Aux 1 Clipper mode also does not have the additional Maximum voltage clip set point adjustment point unfortunately.

You can run the Clipper off of Aux 1's other PV diversion mode though which operates at a fixed clip
voltage and has adjustable High, Low voltage set points and also adjustable Delay and Hold times, adjustable
down to 0.1 seconds each.  That is sort of a PWM but just not as fast as Aux 2's PWM output.

If time allows, Aux 1 could also have the faster Clipper mode PWM just like Aux 2 but will have to wait
a while for that unfortunately, DGD.  Sorry about that.  Aux 2's PWM is done in software  so
Aux 1 is definitely capable, hardware wise of doing that as well.

boB

[dgd]

Thanks for this info boB. its just what I needed.
I will connect my Clipper to AUX1 and see how it goes. Nice to know that PV diversion is also a control possibility.
Would be good to have all the AUX2 Clipper control available on AUX1, just another item for your Classic 'todo' list 
Now i can order a WBjr and have some fun 

dgd

[dgd]

I changed the Clipper over to use AUX1 on my Classic 250. Today the PVs have the battery bank into float by 10.30am and then a nice steady slow breeze had the turbine spinning. I know from past experience with this that there is about 200 to 300 watts being generated.
AUX1 Clipper control is ON and the watts are being dumped into the Clipper resistor bank.
So AUX1 works but with Float mode already active it was just a  switch on. I suppose the real test will happen when there is PV power slowly creeping up to float/absorb and seeing how the Clipper behaves with AUX1 activating below Absorb/Float.

[Olberg]

Dgd
Did you do further testing and can give us more info on how the Clipper behaves when connected to aux1 and in clipper mode?

All the best
/O

[dgd]

It made no difference that I could detect, Average monthly power from turbine is the same.
My Clipper does not need to clip high input voltage very often.

dgd

[ralph day]

What kinds of turbines are people using their Clippers on? 

I have a Bergey XL1.  Works great.  The "blade tip flutter" that happens when it's fully furled and still needs to dump power (called "farts of the gods" hereabouts)can be quite noisy.  Like a Hercules aircraft going overhead at 250 feet.  That happens here too.

I've set the Classic 250 to clip input voltage at 110vdc input max and the Clipper's pot adjustment at 150.  Seems a shame to be doing so but the fotg events seem fewer now and/or of less intensity and duration.  Power is clipped and the turbine slowed before the turbine gets up to the speed that trigger the fotg events. 

Ralph