Classic with Separate Diversion Controller

[boB]

The specs on those look real good boB. 

Did you get one of the 75A 3 phase SSR? 

What's the street price on those Teledyne 3 phase SSR's?

Edward

Yes, and Yes.   (I think)...

Got one of the 75A 3-phase SSRs and one of the DC SSRs.
The street price for the 3-phase is around $132 for one (1) to 24
and the DC SSR is about $170.00   for one to 24....

Looks like quantities will definitely be better price.
Compared to the prices I saw for other DC SSRs from, I think Futureelec
or Crydom (can't remember which one now), the price was no worse for
the Teledyne.    Just a much better part and slightly less  $$$$

I have more AC SSRs coming to me and the one AC 3-phase SSR is going
to 1/2 Crazy for evaluation on something I'm semi familiar with... The Bergey
48V turbine.   We will find out soon I hope if all is well.   I expect so but gotta
be sure.

AC clipping should be much more managable than DC clipping just because of the
flyback energy in the dump resistor.

boB

[keyturbocars]

boB,

That's a reasonable price for a 75A 3 phase AC SSR.  

What's your gut impression of a 50A 3 phase SSR for a 2kW wind turbine (3.5kW peak)?  

From what I saw on the Crydom 50A 3 phase SSR specs, and the little bit of number crunching I did, I felt that it would be sufficient as long as I kept the temps under control.  I didn't see the 50A rating being exceeded on any of the 3 phases - especially considering the Classic will allow the voltage to rise and bring incoming amps down.  

I'm of the opinion "better safe than sorry", and given the choice I would always like to choose a larger factor of safety as long it wasn't too cost prohibitive.

Edward

EDIT:  I just did some more reading on the Teledyne SSR and it might be pretty close to the Crydom 50A SSR that I already have.  From what I can tell, Teledyne rates their SSR as 75A for resistive loads and 50A for inductive loads.  I noticed on this picture of and older part, that they specify on the label 75A (resistive loads).

[boB]

Edward, that looks just like the one I have here.  Either one is probably fine though.
Is the Crydom AC SSR optically isolated ?

Remember that 3 power resistors will need to be used as well.  This would also
enable SSRs to be paralleled as long as the voltage drop is enough across those
resistors.  Something around at least 1.0 Ohm (or more) would work good.

boB

[keyturbocars]

Edward, that looks just like the one I have here.  Either one is probably fine though.
Is the Crydom AC SSR optically isolated ?

Remember that 3 power resistors will need to be used as well.  This would also
enable SSRs to be paralleled as long as the voltage drop is enough across those
resistors.  Something around at least 1.0 Ohm (or more) would work good.

boB

Good question boB!  I am not sure if the Crydom D53TP50D is optically isolated.  Somehow, I thought I read some where that it was, but when I look at the data sheet, I don't see that exact wording.  Can you please see what you think from the Crydom datasheets:

http://www.crydom.com/en/Products/Catalog/5_3tp.pdf

Glad that you mentioned the 3 power resistors are necessary. This is something that I didn't know about.  Now my electronics ignorance will become painfully apparent!  Where/how would those resistors be wired to the 3 phase SSR?

You mentioned that 1.0 ohm would be good.  Any old 1.0 ohm (or more) resistor, or what other specs should I look for?

Thanks,

Edward

EDIT:  I was thinking about the 3 power resistors you mentioned boB.  I wonder if those are needed in cases where the 3 phase SSR will be used to short out the 3 phases of the turbine.  In my case, I will be using my SSR to divert 3 phase power to a 3 phase heater box, so perhaps I won't need the additional resistors.  Maybe I'm thinking about this all wrong, and maybe you can help clear up the fog in my head.  Oh, I guess that might not be humanly possible.    Perhaps at least you can explain the purpose of the 3 x 1.0 ohm power resistors that you mentioned.  Thanks.