Setting RSP-2000-48 stack

Hello EST peoples

I normally live over at electricmotorcycle forum but I figured no one over there but doctorbass is working with the rsp-2000 series meanwells to ask my questions so I figured come over here for a visit.

I received an RMA unit back from meanwell for one of my rsp-2000-48's
Set output voltage on RMA to match the older unit @ 57.1
I checked the input amps on the older unit I didn't send and it was set to 8 when on a full load at some fixed voltage when consuming a 240 v power source (I only tested one line in not both).
I then set the RMA unit to also be 8amps for the same load.

Both units are set to 57.1v at idle, but today when I plugged them into my bike for testing and the RMA unit read 52v while the other unit read 57v ... I am going to assume I did something wrong?
I tried to adjust the amperage of the upper unit again to see if I could push the voltage up but it didn't seem to help :/

Could someone guide me through setting these so they wont blow up ... or is this normal? If there is already a thread on this somewhere I would love to be pointed to it as searching "rsp 2000" came up with eight thousand hits (most of them where for 2000)

I have two RSP-2000-48's in series set to 57vdc ... lots of video on my youtube channel under my zero playlist (latest at bottom showing how I "set" the current going in) https://www.youtube.com/playlist?list=PL9QUUIIdnTqkWeDNdGdTneDyNmxo9tGBZ

Thanks for the advice.

Hello Burton and welcome to E-S!

Here is what i responded you on the electricmotorforum:

Burton, I laugh when i saw you having hard time holding the cam on one hand and and trying to connect various connectors and probe voltage too.. lol.. this remind me when i make my YT vids.. lol I can ensure you that you are not the only one in this situation.

To answer you , even with both psu adjusted the way you used in the vid to get "about " the same current on both psu, this will not guaranty you that you get the same voltage on both.

The way these are built would require incredible accurate adjustment without the V sense connections.. and a simple mV diff make high current variation.. in other words not necessarily like you did with the way you had with the AC ammeter display...

But the good new is that you dont necessarily need to have both psu adjusted to the exact same voltage! And it does not mean that you get less power. If you connect both AC input to the same source then you dont have to worrie.

Both psu are protected by a constant power mode.. so none can overload! once both will have reach the Constant Voltage both will be the same power anyway. You dont have to care if one give more volt than the other.. what is important is that both give the same current witch is true because these are in serie so they dont have choice.. lol... if one have 2 volt more than the other you dont have to care... both still work with in their spec range anyway and none can overload.

But if you absolutely want to have these same voltage.. well.. you can connect the voltage sense S+ and -S for each psu and you should get the same voltage as each psu will fight against the voltage loss in your various connections to get the program ( adjusted) voltage at the location you will have connected the sense wires. I this case if your pre adjustement of voltage is let say 56V on both .. then each psu will compensate and fight to get that voltage at the sense connections on your output wires.


Btw.. the displayed current on the label of the psu is the absolute max current it can draw at the lowest voltage of the given range .. In the DERATING LOAD(%) VS INPUT VOLTAGE spec the non limited power area of the graph start at 180V .. then it is constant up to 264V . the 12.3A you see would be when the psu is at 180Vac input.

if you connect to normal 245Vac source it should draw max 10A.

btw these psu have a overcurrent control that is set to 125% of rated current witch mean when it is in constant current it can give you up to 25% more and constant of the ambiant temp is ideal depending on the AC input and equivalent resistance of the load. As well there is an optimal voltage and current where these psu give their max output. In the case of the 48V model it is optimized to 48V and give the max power and current. It's about 52.5A = 2520Watts output time the efficiency derating: 92% = about 2300W max dc. But at 115% voltage you drop to 87% of the rated current =2001W.

Good luck fort your trip!

A great tip: prepare them to be protected against rain!

Doc

Always impressed with the level of detail which you put into your answers. Thank you sir!

I am just being paranoid since I really don't know why the RMA unit died in the first place I recall you telling me before the voltage sensing circuit would also benefit me via faster charging near the upper voltage limit as well so I will have to get that wired up.

Would it be smarter to put the sensing wires on the controller or at the Anderson connector?
Positive from load would connect to the unit with positive out with that units negative connected to the local terminal negative out.
And Negative from load would go to the unit with negative out and that units positive connection to the local terminal positive out.

If I added a RSP-2000-12 to the stack in series I could get the extra 300w per unit, or 900w ... or I could buy a whole new stack for 900, get the J1772 circuit going, upgrade all the diodes (since they are only 60amp), and get 4000w I can only imagine charging at .8C, going to try just one stack to see how it goes first. If I add another stack I will have a couple other issues to consider as well ... like do you then run 2s2p and use current sensing between the units and if so how would that work in that setup etc. (but that is later)

As for rain protection and rain in general. My thoughts were to just put it in my top case when not in use but can you charge while it is raining? I think the chargers are rated up to 90% humidity and I would have to avoid conditions where it would be cold out and condensation could form. Have you found any good "weather proof" but breathable boxes for a complete compact solution with inline J1772? I have seen some designs for these boxes but none the size I would require.

Rain and humidity seem to be my biggest obstacle. I was thinking of making a new "tank" for the bike to increase storage size so I could place these chargers in there on touring days. Right now all the wires from the birds nest are on top my battery and inside the tank area. I don't think a RPS-2000 can fit on top the battery because the frame would get in the way.

OK, now I am rambling. Thanks for the input!
I will cross link from the motorcycle forum to here so we avoid having to update two forums