[RE-wrenches] RFI from MPPT Charge Controllers

[Larry Crutcher]

Hello Frank,

Looks like your low pass design cutoff frequency is below 500 kHz. I  
had not thought of this but I'll try it. Do you know where to find the  
coil that large?

I would think that just by the nature of their design that an MPPT  
controller would have this filtering.

Thanks,

Larry Crutcher
Starlight Solar Power Systems

On Sep 1, 2010, at 7:19 AM, Frank Lewon wrote:

> We recommend making a Pi filter consisting of a 50 uH 30 amp medium  
> Q coil and .1uF 100+ volt disc capacitors. Insert the Pi filter in  
> the PV+ line. Wire with short direct leads to the control. Helps a  
> lot. Not perfect.
>
> Frank Lewon
> BZ Products Inc.
> 7914 Gravois Road
> St. Louis MO 63123 USA
> 314-644-2490 www.bzproducts.net
>
>
> On 8/31/2010 7:00 PM, Larry Crutcher wrote:
>> Does anyone know of a large MPPT controller that does not produce  
>> RFI? Specifically, customers that are SWL, AM or amateur radio  
>> operators need RF quiet time during the day while operating or  
>> listening. All the controller I have installed make some noise. The  
>> Outback MX60 in my RV decimates every 40 kHz or so with broadband  
>> noise from 160 meters and up.
>>
>> Does anyone know how the Xantrex SW, Tristar MPPT or Apollo do with  
>> RFI?
>>
>> Many thanks,
>>
>> Larry Crutcher
>> Starlight Solar Power Systems