Extending remote temperature sensor wire.

[mserafi1]

I ordered a remote temp sensor for my Tracer BN 4215 MPPT solar controller that was supposed to be 3 meters in length but arrived 1 meter in length . Shockingly, AliExpress and the manufacturer show no desire to resolve the issue. The manufacturer denies selling it, and AliExpress says "so solly, no help can do". My punishment for shopping commie.

Can the wire be extended? It has a specific connector for the controller, so I'd have to splice a piece into the middle. Or, alternatively, are these a standard design that can be sourced domestically?

Regards and Merry Christmas
Mike S.
SV Escaped from New York



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[transmitterdan]

Almost all of these sensors use what is called a "thermistor" which is a device that changes resistance as temperature changes. Another type of device is known as a "thermocouple" which is not a resistor. It is 2 types of metal that when they are welded together create a tiny voltage (like a battery) where the voltage changes with temperature. Thermocouples require special wire and the length should not be changed. It is almost 99.9% sure you don't have this type of sensor.

If the wire is just regular wire with a plug then it almost certainly is a thermistor sensor and will be ok to extend the cable by splicing in another piece of wire. Just make sure you make good connections to the wires and keep the wiring the same as it was by making sure to connect the same color wires together. The best way is to cut and splice one wire at a time so you don't get mixed up.

[mserafi1]

The wire is not shielded or twisted; just ordinary red and black wire. So, it looks like I can just lengthen it with a length of similar marine grade wire of the same gauge . Thanks for the help.


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[Wotname]

Originally Posted by transmitterdan

Almost all of these sensors use what is called a "thermistor" which is a device that changes resistance as temperature changes. Another type of device is known as a "thermocouple" which is not a resistor. It is 2 types of metal that when they are welded together create a tiny voltage (like a battery) where the voltage changes with temperature. Thermocouples require special wire and the length should not be changed. It is almost 99.9% sure you don't have this type of sensor.

If the wire is just regular wire with a plug then it almost certainly is a thermistor sensor and will be ok to extend the cable by splicing in another piece of wire. Just make sure you make good connections to the wires and keep the wiring the same as it was by making sure to connect the same color wires together. The best way is to cut and splice one wire at a time so you don't get mixed up.

And a quick and dirty way to tell which is which to carry out the following simple test.

Use a DMM set to DC millivolts across the ends of the wire and heat the sensor. A thermocouple will show a few millivolts. If it doesn't, repeat with the DMM set to the ohms range as the thermistor type will show an increasing resistance when heated.

I not sure exactly what type of sensor you might have but I agree it is more likely to be a thermistor type although some are now ditigal. These will usually have a screened or shielded wiring.

[socaldmax]

Originally Posted by mserafi1

The wire is not shielded or twisted; just ordinary red and black wire. So, it looks like I can just lengthen it with a length of similar marine grade wire of the same gauge . Thanks for the help.


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I'm almost positive the other guys are right and you have a thermistor. You can simply extend the wires, but according to the instructions from a different controller, they stated that the extension wires had to be equal length.


In regards to your Tracer 4215, after you get it installed, keep an eye on it as far as output goes. I bought a Tracer 4210 (similar, just 100v Max input instead of 150v) and I was very disappointed in it's inability to lock onto MPP. A good performing MPPT controller should determine the correct V in a matter of a few seconds and make max power, readjusting periodically as shadows pass over the panel.

My unit performed exactly like the video I saw on Youtube, where it took a long time searching but never really settling on the correct voltage, wasting a lot of power by being either above or below the MPP. I didn't feel it was working well enough to install it, so I'm using it as a paper weight. It's been posted that the mfr has claimed they would update the firmware, but so far, no good news.

I have a very strong suspicion that the engineer they hired to design it and/or write the firmware doesn't really know what he's doing. I've worked with a few engineers in my time, and most of them were great at designing whatever it was we were working on, firmware updates were for minor glitches or slight tweaks to refresh rates or responsiveness, etc. This is an all out failure of the algorithm to determine MPP, which (should be) actually a pretty simple comparator process. As I'm fond of saying, just because someone has the job doesn't mean they're the best at it, or even competent.

I'm hoping to hear back from you to see if perhaps yours is working correctly, maybe they quietly fixed it. Good luck!

[Symphony]

Good engineering also expects one to test that the product behaves as expected once the hardware is set up. This product sounds like the algorithm and other basic engineering may have been "borrowed" from another manufacturer.

[mserafi1]

I agree with the competency theory. It's been an impossible conversation with these guys to correct the order or even explain that a 3 foot wire length does not a remote wire make by any stretch of the imagination....I hope this thing works when it's installed. I'll post the results after completing the install.

Merry Christmas all!

Mike S.

[socaldmax]

Originally Posted by Symphony

Good engineering also expects one to test that the product behaves as expected once the hardware is set up. This product sounds like the algorithm and other basic engineering may have been "borrowed" from another manufacturer.

It looks to me like the "Tracer" series of solar controllers are made by 3 or 4 different companies, or sold by different companies and they slap their name on them. There are also a couple of different physical designs, but all using the "Tracer" name. I don't know if they all suffer from the same bad algorithm, but the Youtube video by the Aussie is one model and mine looks different than his, yet they both behave the same.