Trace controller application question

[TomW]

Folks;

Any comments welcomed, especially from someone who has experience.

The question boils down to this:

Is it feasible or even possible to run a pair of trace C60's in parallel on the same battery bank to increase the Load Diversion [dump load] capacity? Hypothetically it would be on a 24 volt system that occasionally goes over the rating for the C60.

My first thought was that you could slightly offset the trip points so that one is "primary" and one is "secondary". Perhaps they would work just fine in parallel with same settings but I thought I should see what the savvy folks here thought of the idea before i go further on planning this hypothetical system.

Thanks in advance for your time.

Cheers.

TomW

[iFred]

Tom, as far as I know you can hook and should hook them in parallel to increase your input/output capacity. They are designed to be run slightly higher then their ratings, so I don't see a problem. The c60's I believe could handle 12/24/48 at 60amps each.  The inputs would go to both controllers equally in parallel, and the outputs could be either separated "one as diversion load" and one as "batt charge" as far as I am aware without problems (set limits), you could also hook both outputs as diversion loads in parallel. Provided both units are fed the exact same input. I don't see a phase problem. Lets see what others say on this.

[windstuffnow]

  Tom,

     I use 2 C60's for controlling the charging input.  Although, one is for wind and is a diversion to a resistance and the other is for solar which is simply used as a controller.

     From what I understand I can use both as a dump in paralell and simply connect both the wind and solar comming in to the batteries and both C60's in paralell to dump loads.  In controller or diversion mode they work exactly the same with the exception of what they do with the power when the batteries are full. ( one dumps one shuts down while maintaining the voltage at a set parameter).

     The voltage set points have to be exactly the same for them to work in conjunction with each other ( ie  automatic equalization, bulk or absorbsion) otherwise one will be dumping the other ones charge working one more than the other.   I had to play around with the settings to get them to work together but they seem to do fine now.   It would be nice if Xantrax would have some kind of sync line that could be installed between them to make them work together automatically but once their dialed in they seem to work good together.

Have Fun

Windstuff Ed

[Victor]

Hi Tom,

 I don't have direct experience with C-60's in diversion mode. That said, the current  the controller "see's" is dependant on the battery voltage and the load it is diverting to. As long as the dump loads are sized correctly and  the outputs of the diversion controllers are not paralleled there should not be any problems.

 In other words each controller is current limited by the size of it's diversion load and doesn't "realize" the other controller is even there. This eliminates all the problems of synchronizing the controllers. It will probibly work best if the voltages are set .1 volts  or so apart to avoid interaction.

Make the wind fun!

Victor

[windstuffnow]

Victor,  

What I've found with mine is when their set differently one seems to do all the work.  When you set them up and say the absorbsion is set at 13.7 volts and the bulk is set at say 14.5 volts but the second bulk is set to 14.6, when the bulk has been at or above that voltage for a time of 2 hours one will go into diversion mode to lower the voltage to 13.7 the other one set at 14.6 wont and will wait until the voltage has reached the 14.6 for 2 hours at which point it won't.  So one goes into absorbsion dumping until the voltage reaches 13.7 and tries to hold it there.  Since the second one didn't get the 14.6 for two hours wont divert the power and that leaves only one doing all the work.  If their sync'd together both will see the voltage equally and work together with the incomming power to keep the batteries at the preset voltage.

  This is my first year using the C60's, so I'm definately not to be considered an expert with them.  Just my experience watching them work together ( or not ) and tinkering with the settings until they worked together nicely.  It might be best to contact Xantrax directly for a detailed "expert" opinion connecting the two together for the best results.  I used to use some homemade shunt regulators that were set at .1 difference between them but didn't do anything more than divert power when the batteries reached 14.4 volts or higher, no fancy bulk, float, and equilization modes...

Have Fun

Windstuff Ed

   

[richhagen]

I have two C-40's, I don't have them rigged that way, but you can hook them up in parallel as diversion load controllers, provided that you set the threshold voltages such that the voltage drop when they both kick on doesn't drop the potential from the batteries through the cables below the set point for the low voltage and turn off the load controller.  That would result in the diversion loads being continuously turned on and off.  The C-60's are basically similar to the C-40's, so it should work fine.  Rich Hagen

[Victor]

HI Ed,

 I see your point. I wasn't thinking about the other stages of charging (float) as I don't use them. Why divert away wind generated electricity and then use another source to equilize? Is my attitude.

 As far as one doing all the work, It's workload is determined by the load resistance. If that is enough for all of the work, so be it.

 I suppose if you want a lower voltage for float (absorb?) then you have to synchronize them as you described. I would expect this to be more difficult than you experienced, I would also expect the temperature drift to be different between units requiering frequent fidiling to keep them operating together.

Have you had any problems of that sort?

Make the wind fun!

Victor

[windstuffnow]

  I haven't had any noticable problems as yet.  I don't use them both as diversions.  One simply shuts down the incomming solar.  I plan to change the solar to a diversion controller this summer.  We typically have an abundance of sun in the summer and its quite typical to have the batteries charged by noon daily and I want to divert the solar to another load.  No sense wasting it by shutting them off.  I plan to change the resistor bank to drive the load on the wind side also... should be interesting.

Windstuff Ed

[TomW]

Fred; Ed, Victor, Rich;

Thanks for your feedback! I guess the bottom line is that it can be done. As usual there are likely some parameters to how.

Thanks again and sorry for the delay in saying so.

Cheers.

TomW