benefits of clipper as opposed to strictly dump loading

[ralph day]

Hi
I've installed a new Bergey XL1, MS Classic 250 and just the breaker/rectifier box.  I've got dump loading set up (took a while before commissioning the turbine), but am not happy with the results. 

The flickering of lights is becoming annoying, and the freewheeling of the turbine (if I don't have the dump loads correct) is just a waste of turbine. 

I'm wondering if it's worth getting a clipper?  I"ll still be able to run dump loads when in absorb and float, correct?  One aux function from the MS controller and the old standby from the MX60. 

Income tax return is coming in the mail...might just cover the cost of a clipper.

Thanks for any comments and/or suggestions.

Ralph

[dgd]

The Clipper is essentially a protection device for both your turbine and the charge controller. It measures incoming voltage and at a set point will start 'clipping' the voltage by inserting load resistors into the circuit.
The Clipper can do this independantly of the CC so that even if the CC fails then the Clipper will slow/stop a runaway and possibly self destructing turbine.

It can also be wired to AUX2 of the Classic and use the PWM signal provided to limit input voltage when the Classic is current limiting in Absorb and Float stages of battery charging.
Since AUX2 is used in Clipper Control setting it means you do not have this AUX available for PWM control of a load (such as water heating element).
Midnite can provide the correct value Clipper resistors for the XL1.
IMO its a good idea to have a Clipper

There should be no problem using other dump load devices as these are probably connected to the battery and not the Classic input/turbine output

dgd

[ralph day]

Okay, got the clipper.  It's the 1.5 ac unit for the Bergey XL1.  Goes with the 250 Classic.

There's no fan or metal enclosure around the resistors as shown in the installation manual.  Not enough heat to bother the electronics?  Enough convection  to remove the heat generated? 

I was able to mount the clipper directly on drywall ( found a stud right in the middle of the enclosure, the mounting rails keep it out from the drywall by 1/2 inch or so).  Is that ok, or should it be mounted on plywood?

Turbine is laid down while the clipper install takes place.  It's 30 day checkup co-incided with the clipper's arrival.

Any hints about the max voltage pot adjustment from any Bergey owners?  250v, 200?  150 if you're going to be absent for a while?

Thanks

Ralph

[dgd]

That voltage adjustment pot is to limit the high voltage output by the Clipper and should be set to match the high voltage rating of your controller, 250v for a Classic 250.
The AUX2 'Clipper Control' will feedback from Classic to Clipper to bring load resisters online
and slow/protect the turbine so setting pot to lower voltage will, AFAIK, not be necessary.

dgd

[ralph day]

Up and flying with the Clipper  on board.  Quiet!  The nearly constant whistle the turbine would produce in low or non-productive wind is gone today.  Enough solar to fulfill all our charging and needs, so the clipper keeps the turbine pretty much braked.  It will be  interesting to hear any of the roar the turbine puts out in furling flutter, if it gets to that stage again.

My first 20 days with the Bergey produced 46kwhrs in April.  Usually April will produce 40-45kwhrs for the entire month.  I figured on reaping 1.5 to 2 times as much energy with the new turbine, but it appears I won't.  I used to have the old H80 diversion voltage settings higher than the system absorb all the time.  Any wind went into the batteries or dump loading.  |With the classic and clipper that's going to change.

Ralph

[ralph day]

A good windy day provided the rumble and roar that comes with a Bergey Xl I suppose.  Not too bad though.  The clipper gets some warm though.  I felt the outer box and IR temp gunned it.  60C at the hottest point, but right over the circuit board it was 4 degrees above ambient room temp.  I guess it really doesn't need a fan, just lots of unobstructed convection cooling.

Ralph

[ralph day]

The clipper manual states that the input voltage (to the Classic) is held to zero volts by the shorting breaker in the stop position.  Fine, understood, and the blades of the turbine slow to a stop, or just revolve slowly.  My question is, when the breakers are in the stop postion are the resistors heating up if a strong wind starts spinning the shorted turbine?  My old H80 would just become the resistor, turbine and wires shorted together were the heat load.  It once went full speed while "braked".

If the resistors are supposed to be heating in the stop position that's fine, that's what I'd like.  If not, then can I just use the input voltage adjustable pot and swing it to zero?  That's definitely putting the energy to the resistors, correct? 

boB, in aother  thread: "Shutting down the turbine in a storm may be the best option for any wind system just to be on the safe side."  Sounds like good advice, but my experience (H80) showed me that braking can be overcome, turning your turbine into a heater.   I just want to be sure that "braking" isn't just what I had with the old H80 system. 

In simple Gronk talk:  Clipper "stop" get hot?  Yes or No.
Any input would be appreciated.

Ralph

[Halfcrazy]

If the "Manual" stop switch is applied it is a direct short. If Aux2 is set to manual on then it goes into the resistors. So for turbines that are soft and can be over taken by a strong wind I recommend using Aux2 manual on

[ralph day]

Thanks very much Ryan (I think Ryan is HalfCrazy, do you?)

Ralph

[vtmaps]

Thanks very much Ryan (I think Ryan is HalfCrazy, do you?)

I am an optimist.... the glass is half full.  I see Ryan as being half sane.  --vtMaps

[atop8918]

Yeah, half crazy -- like a fox.

[Halfcrazy]

Hm Sane? Me NO WAY