Parallel Operation of 2 Astron RS-70's ...

[Klondike Mike]

Advice on how to hook-up the device being powered. + goes to PSU #1 and - goes to PSU#2? ... or should there be a buss bar connecting the + & - between the two PSU's and then the device would connect to the buss bars. Am I over-thinking this?

 

[camaro1]

parallel would be - to - and + to + and the parallel connection to parallel connection just to keep the regulators in sync?


I wouldn't connect + to -,, that's how series wiring works and doubles the voltage,, you want parallel wiring to double the amperage

 

[Klondike Mike]

parallel would be - to - and + to + and the parallel connection to parallel connection just to keep the regulators in sync?
I wouldn't connect + to -,, that's how series wiring works and doubles the voltage,, you want parallel wiring to double the amperage

You added the question mark as if you were asking me a question, so I'm not sure of the intention of your statement. I do realize the concept of series and parallel as it relates to voltage sources.

I guess I posted my initial comment before totally thinking it out but that was the intent. I was wondering how others have done the hook-up;

1) just running heavy gauge wires between and then hooking device up to one PSU or ...

2) using some type of buss bar between the two units and tapping off at the center.

Does this matter regarding the current levels involved?

 

[davegrantsr]

1st, check that both PS's are putting out the same voltage. For lack of a better way to do it, take an item-say an amplifier that SHOULD draw 40 amps. Hook it to 1 PS & DEAD KEY on AM-no modulation. Lets say it draws 35 amps. Now, hook it to the other PS. If it draws a different amount of current, say less then 33 or more then 37 amps, i'd be a bit hesitant to combine those 2. (You need to measure current draw with an external ammeter, not the one built into each PS-you dont know that they're accurate/the same). So lets say you show 35 amps draw, dead key on AM with 13.5 volts on each-you're good to go. Next, KNOW the draw of what you plan on using & use the appropriate size wire. You could use a bus bar-of the appropriate size for current draw, or just connect + to + and - to - using the appropriate size wire for current draw, and run the appropriate size wire to the item to be run. Dont run the PS's in series to run multiple items, just 1 item, such as a dx1200 or dx1600. Dont add a radio as well, it should be on its own PS.

 

[Klondike Mike]

Well, here's what I ended up doing. Bought a 15", 4 gauge starter wire from the local auto parts store and cut it in half and soldered on some ends;

Going along with what davegrantsr suggested, I will adjust my voltages on each unit to be around 14v. The one unit I have I added a external voltage adjustment mod to it and the other I'll have to pull the cover to make the adjustment;

And lastly, here is the final hook-up. I'll need to get some battery end boot protectors just to make sure the ends are covered. With the heavy gauge wire, there is no movement. I'll hook up the device to be powered to the top of the mini buss bar;

In case you were wondering what device was going to be powered by this setup, here it is. My monkey quit on me so I needed something to power the crank;

 

[Mudfoot]

Good stuff.

 

[Captain Kilowatt]

Normally when you jumper the posts in the back labeled for parallel operation only the voltage regulation and hence output is controlled by one of the supplies. It becomes the master and the other is the slave. Normally with these there is no need to balance the voltage but since you modded one all bets are off on that one. The reason i didn't chime in earlier was that i have heard two different ways to hook up the dc. One says to bridge them as you did the other says to take the pos from one and the neg from the other. Never ran two astrons before so i couldn't say.

 

[Klondike Mike]

1) Normally when you jumper the posts in the back labeled for paraller operation only the voltage reulation and hence output is controled by one of the supplies. It becomes the master and the other is the slave.

2)i have heard two different ways to hook up the dc. One says to bridge them as you did the other says to take the pos from one and the neg from the other. Never ran two astrons before so i couldn't say.

1) I'm not sure what the Astron's parallel link wire does, I'll have to study the schematic.

2) Yes, this is not as clear as one would think, hence the post. My initial picture and thought was that of your "pos from one and the neg from the other" but discounted that, thinking it would not work having an open connection on each supply. Good to hear it was not crazy thinking on my part.

 

[Captain Kilowatt]

I wish you the best of luck. I looked at the schematics and found nothing about the jumper link for parallel operation. i also read the operations manual and Astron seems to be keeping this one a secret. They have no mentions tat all about how to do it even though their heavy power supplies are capable of doing it. i even googled it and that is where i came up with both ideas. Yeah it seems odd to me about taking the pos offf one and the neg off the other but that is what a couple people were saying. Maybe they were talking about getting 24 volts but they were talking about in parallel for 12 volts. It would certainly help if Astron would just stop the foolish....no idiotic, secrecy and just tell people how to wire it up in their manuals.

 

[Mudfoot]

Do any of the Astron manuals describe how to do it? I could swear that I read about it a long time ago. I've never seen anyone do it. Might send them an email or call them.

I read an old thread on Fwed's site, they all seemed confused and in disagreement.

 

[Klondike Mike]

1)Do any of the Astron manuals describe how to do it?

2)Might send them an email or call them.

3)I read an old thread on Fwed's site, they all seemed confused and in disagreement.

1) Couldn't find a manual for it.
2) I think I may give them a call on Monday to confirm.
3) I did find a previous thread on this site with the apparent answer and confirms idea #1;

Correct about the above. I used to run three 50 amp Astrons to a solid state amp. The special lug on the back goes to circuitry that is designed specifically for running these PSs together. The wire you run from one PS to the other is a link between them. You do not take power from this link. You use the main power lugs to hook up your equipment. Also when hooking up, take the + from one PS and the - from the other this was suggested to me from one of the Tech's at Astron.73

 

[Klondike Mike]

I wish you the best of luck. I looked at the schematics and found nothing about the jumper link for parallel operation. i also read the operations manual and Astron seems to be keeping this one a secret. They have no mentions tat all about how to do it even though their heavy power supplies are capable of doing it. i even googled it and that is where i came up with both ideas. Yeah it seems odd to me about taking the pos offf one and the neg off the other but that is what a couple people were saying. Maybe they were talking about getting 24 volts but they were talking about in parallel for 12 volts. It would certainly help if Astron would just stop the foolish....no idiotic, secrecy and just tell people how to wire it up in their manuals.

Thanks for doing some of my homework for me CK. I just went through the schematic and there is no mention of the parallel hook-up port.

Looks like we have our answer though, the one we thought least likely but most likely to load balance.

 

[Captain Kilowatt]

I would hook them up that way and test it with a volt meter if you have one. Next I would hook up an old car headlamp or something made for 12 volts that will draw several amps first before connecting anything too valuable to it. You know....just in case.

 

[Klondike Mike]

I would hook them up that way and test it with a volt meter if you have one. Next I would hook up an old car headlamp or something made for 12 volts that will draw several amps first before connecting anything too valuable to it. You know....just in case.

Good idea. I have a test subject in mind. I am awaiting some eBay Anderson connectors that are on the way, so final test results will be delayed until I receive them.

 

[Klondike Mike]

Well ... I finally have THE answer, from Astron tech support nonetheless. I hooked up my supplies as per the last recommendation (ie. load on POS of one supply and NEG on the other). I was noticing some funky behavior between the two but was getting output. I hooked up a test load and all was well, but still funky. I decided to call Astron tech support and get a clarification. Fred instructed me in this fashion;

1. Adjust voltages on each supply to match each other.
2. bridge the supplies; + to +, - to -
3. hook up load to + on PSU #1, - to PSU #2
4. hook up 20 gauge wire between the parallel connection posts.

Looks like the answer was not one or the other, but BOTH. Now that I think about it, this makes the most sense. Still waiting for my Anderson connectors. The ones I got from eBay were 1/3 the cost as compared to buying from Newark online. Finally found a local source with good pricing for 4 and 6 gauge wire. Nice when you can find stuff locally.