A Question on MPPT Controllers

[grizzzman]

It grabs the insulation.

I included a link above to the PDF that shows how to install it.

Have you installed one?

 

[seneysolar]

It grabs the insulation.

I included a link above to the PDF that shows how to install it.

Shoot i even watched the video and it breezed right over the wire clamp part. Do you have a up close picture of this. Ill be ordering one for my cc asap to try it out.

 

[Hedges]

I'm quite contempt with my cheap PWMs for now.

Oh, I don't know about that. It sounds like your contempt is for the terminals Victron uses.

I give all wires a "tug" on occasion, the ones i find loose are on my PV/DC breakers from Midnight, those need occasional tightening.

Any connector should hold the wire tightly. In the case of crimp terminals, withstands many pounds, hundreds of pounds for larger wire sizes.
Wires in the Victron or any other screw terminals need to hold even when pulled fairly hard.

You need to use fine stranded cable on those Victron SCC terminals.

That is apparently due to contact resistance and heating, not likely mechanical clamping. But maybe fine wires settle better at low clamping force.

I got a feeling this post might get me some backlash, but I don't know where else to ask.

Don't worry about that, all part of the fun here. So long as people also provide actual advice.

I had recently ordered a Victron 100/20 but had extreme difficulty getting it wired up. The terminal ports on the underneath, regardless of how tight the cables are, always move around and eventually pop out. ... I have attached two photos of the 100/20 and the PWM side-by-side... The ones which Victron (and some Renogy ones) use are giving me great safety concerns.

What wire gauge did you use, and what do specs of the SCC call for?
You could also provide a photo of wire in terminal. Try pulling, report how easily it came out.
If wire was too small, the clamp wouldn't compress it.

I haven't used fine wire except for 2/0 or similar battery cables, but none for these smaller terminals.

The problem I do have is that screws torqued to spec on coarse stranded wire work loose. And the force applied by screw turned with screw driver (I don't have a torque screwdriver) is quite small, no where near what crimping provides. I've had circuit breakers run hot and occasionally a wire comes loose easily. Have to wonder if I didn't slip them under rather into the opening.

What I do is with wire bent in an "L" or "J", I wiggle it so it rotates in the screw and repeat tightening. I installed a utility meter socket & breaker recently with 3/0 cable. Torqued to 20.5 ft. lbs., after wiggling it was able to turn more, several cycles of that.

And certainly the wires do need to go in far enough, as a drawing posted above showed, so terminal parts don't tilt and try to squeeze it out.

 

[RV8R]

I got a feeling this post might get me some backlash, but I don't know where else to ask.

I had recently ordered a Victron 100/20 but had extreme difficulty getting it wired up. The terminal ports on the underneath, regardless of how tight the cables are, always move around and eventually pop out. Now I've been using a rebranded PWM controller for years (and its still in use), but a few here had roasted a previous post I made where I stated the fact I'd prefer staying with PWM over MPPT for their simplicity, despite not being as efficient. I have attached two photos of the 100/20 and the PWM side-by-side; my question is are there any MPPT controllers that use screw/bot terminals? The ones which Victron (and some Renogy ones) use are giving me great safety concerns.

Thanks!

You are getting lots of great advice here ;

I also have that PWM charger, but do not use it any longer. Note, typically the Victron requires battery voltage plus 5 volts to get the system to start .




On the Victron unit;

Don’t use ferrules & use the right fine wire multi strand;



The above wire is “Marine Grade” ,,, You can buy it at a local Boat “Marine” Store.




Regarding Backlash ,,, This should never happen, but unfortunately does. The internet can be tough to get thru if you are learning about such things as this, but there are good Members on this Forum that just want to help you out. We all had to learn this stuff from somewhere, as none if us were born knowing it. It is very difficult for inexperienced DIYers knowing who to trust on the internet ,,, I get that. Unfortunately people come with egos & we all have to deal with that stuff. Stick it out & you will learn & have the knowledge. Everything we do comes down to “Knowledge & Motor-skills”. You seem to have a DIY interest ,,, Hang in There it gets easier !!

 

[HRTKD]

I have the Victron 100/20 as well as two Victron 100/50 solar charge controllers. All three use fine stranded wires (6 gauge welding cable) with ferrules as well as strain relief clamps. These are installed in my bumper pull toy hauler camper. I've been down some very rough roads as well as the lousy Colorado highways. None of my wires have come loose. The strain relief is critical in my opinion. Almost every wire in my system is secured.

@highwaypirate , if the folks at the solar supply house were unable to get the wires tight in the Victron solar charge controller, it's possible that the screw terminals are damaged. See if you can get it replaced under warranty.

 

[Mattb4]

Sadly I think the OP has left the building.

 

[G8trwood]

Doesn’t current connected have an mc4 pigtail connector specifically for this issue

 

[seneysolar]

Doesn’t current connected have an mc4 pigtail connector specifically for this issue

Doesn't seem like it. The kit they offer with a victron controller uses 7 strand pv cables, kinda the opposite of what victron recommends for "high strand"?

250V/70A Solar Connection Kit | Current Connected

This 450V/100A Solar Connection Kit has everything you need to connect your solar panels to your power system. Enjoy the benefits of renewable energy!

www.currentconnected.com

 

[Andrewr05]

I was right in the beginning; backlashed again for a simple question. I'll request this thread be pulled.

Nah, don't leave because of one guy being a dingleberry.

Its the terminal screws that are the problem, although I have looked at that item.

I know, user error.

In what possible situation is this helpful?

 

[Hedges]

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[OffGridForGood]

No. Solder will wick between wire strands and bind the strands making this connection a fire hazard because solder can melt and loosen the connection. Happened to me once. You should never crimp or compress soldered wire.

Melting the solder = 180 degrees C = wire is too small ? (there are high(er) temperature solders available).
I can see the issue if the compression is lost due to the wire effectively changing diameter. I was trying to think of a way to make the wire 'bigger' just at the end, behind where the set screw would clamp the wire. This is the basic method behind many types of cable end restrains.
Maybe it would be too difficult to keep the solder from wicking up and getting into the compression zone.

 

[RV8R]

You are getting lots of great advice here ;

I also have that PWM charger, but do not use it any longer. Note, typically the Victron requires battery voltage plus 5 volts to get the system to start .

View attachment 196180


On the Victron unit;

Don’t use ferrules & use the right fine wire multi strand;

View attachment 196182

The above wire is “Marine Grade” ,,, You can buy it at a local Boat “Marine” Store.




Regarding Backlash ,,, This should never happen, but unfortunately does. The internet can be tough to get thru if you are learning about such things as this, but there are good Members on this Forum that just want to help you out. We all had to learn this stuff from somewhere, as none if us were born knowing it. It is very difficult for inexperienced DIYers knowing who to trust on the internet ,,, I get that. Unfortunately people come with egos & we all have to deal with that stuff. Stick it out & you will learn & have the knowledge. Everything we do comes down to “Knowledge & Motor-skills”. You seem to have a DIY interest ,,, Hang in There it gets easier !!

The equipment above in the last photo is for my “Portable” Solar Charging System ,,, Well if I ever get around to completing it . It is being build to remotely charge equipment batteries in the wilderness.

So, to get myself from Solar Panels to Victron MPPT I am pondering utilizing “Breaker Switches”. MC4 pigtails on one side ( panel ) & that #6 Marine fine wire from the breakers to the Victron.





What Say You ?

 

[AntronX]

Melting the solder = 180 degrees C = wire is too small?

Soldering wire strands together makes them behave as single strand solid wire but with melting point of solder instead of copper. Solid wire will have sharp contact points inside the terminal block which would run hot due to small contact area. If it gets hot enough to melt the solder the whole connection gets loose and fails burning up.

 

[sunworshipper]

Yes. It's for an SUV that frequents rough roads and fields (I supply power for remote workers).

In your case, a PWM is better. You have prioritize reliability over efficiency. I assume that you have the panels are wired to match the battery voltage (12V battery and nominal 12V panels in parallel). If a PWM controller fails, you can simply connect the incoming solar positive to the battery bank positive to charge the batteries 10 about 14V and disconnect. You are acting as the charge controller. If the panels are wired in series as for use with a MPPT controller, you're dealing with 50V or more; and the current will be a lot lower.

If I were in your position, I would wire a PWM controller bypass switch rated for the max solar Isc between the incoming solar & battery positives. Make sure you start a timer on your phone to turn this off in a timely manner!

 

[Q-Dog]

Have you installed one?

I started to but decided it wasn't need for my install.

 

[Q-Dog]

Nah, don't leave because of one guy being a dingleberry.



In what possible situation is this helpful?

Are we not supposed to help people here? how is ignoring the problem going to help?

 

[efficientPV]

I never read this thread, but had to laugh when I saw the circuit breakers. I have one that is a 32A PV disconnect. I tested it at 90A and it didn't trip after a minute at that current. I had to stop the test because of an overheating connector.

 

[Supervstech]

Are we not supposed to help people here? how is ignoring the problem going to help?

If you feel a response is needed...

Make a teaching contribution.

Or dont respond.

Insults are rarely helpful. And when they are helpful, there is an instruction to go with it.

User error is a comment... not a helpful response.

How about, it sounds like a problem getting the correct wire in the connecror correctly. The wire needs to be flexible enough to be compressed by the connector, inserted to the stop in the correct placement, without any insulation in the way, and tightened with a properly fitting screwdriver, torqued to proper tightness.

 

[Q-Dog]

So, pointing out to someone they could have made a mistake is an insult? Oh boy!

 

[Supervstech]

So, pointing out to someone they could have made a mistake is an insult? Oh boy!

How is "user error" a helpful comment? How is it pointing out they could have made a mistake? The post says "user error"
That isnt a "could have made a mistake"
That is a the problem is you post...

Be helpful. Or do not respond.
User error with a method to solve it is great...


Just saying "user error" is posting for the sake of posting and that is specifically against the rules of this forum.