Hello all,

Our TSP 5kw Axpert type inverter is doing a weird thing. As after connecting the battery, the inverter turns on momentarily, then the battery voltage drops to about 32V and the inverter shuts down again. Battery is brand new and sitting at 54V. 

It almost seems like there is a relay that causes a short circuit somewhere.

Any ideas?

30 minutes ago, ErichK said:

Hello all,

Our TSP 5kw Axpert type inverter is doing a weird thing. As after connecting the battery, the inverter turns on momentarily, then the battery voltage drops to about 32V and the inverter shuts down again. Battery is brand new and sitting at 54V. 

It almost seems like there is a relay that causes a short circuit somewhere.

Any ideas?

1st call is to Thesunpays for help. They supplied it. 

2nd point. If the battery drops to 32V the inverter must switch off as its below the cut off voltage. 

3rd. The not so easy is to find out why. 

If you connect it to the grid so that it has a power source to operate does it still switch off? 

7 hours ago, ErichK said:

the inverter turns on momentarily, then the battery voltage drops to about 32V and the inverter shuts down again.

The inverter can't operate at 32 V, that's why it shut down. There must be a wiring fault or problem with a battery isolator/fuse/breaker, or the battery is faulty (weak cell). Another possibility is the battery BMS disconnecting from the inverter for some reason, so the 32 V is just from capacitor residual charge.

 

7 hours ago, ErichK said:

It almost seems like there is a relay that causes a short circuit somewhere.

My guess is that you're hearing an inverter or load relay coming on, signalling the start of heavy current draw from the battery. So the relay may not be the cause, but rather something that happens just as the battery current becomes high. Even with low loads, starting up the inverter takes several amps for one second or so. I get this problem when testing an inverter on the bench with a lab power supply; the voltage and current has to be set near the power supply's limit to start the inverter.

So my Dad opened it up and let his electronic technician friend have a look. Couldn't see anything visibly damaged or burnt. He did solder one spot that looked like a dry joint. Put it back together and has been working fine for a day now.

Who knows for how long but we can only hope. It is going to hurt the pentioners' budget if he has to replace it now.

Edited March 3, 20233 yr by ErichK

.......and it worked for 24h, then the same symptom again. Shuts down. Replacing it now.

5 minutes ago, ErichK said:

.......and it worked for 24h, then the same symptom again. Shuts down. Replacing it now.

A friend had the same inverter and took it to Thesunpays and it was repaired and its working well for more than a year now. 

Thanks for letting me know. I'll tell dad to take it in. We'll call them in the morning.

8 minutes ago, ErichK said:

Thanks for letting me know. I'll tell dad to take it in. We'll call them in the morning.

Inverter has to be booked in and wait for the quote. 

Ok, it is a 500km drive for him.

TSP says +-R3k for refurbished motherboard. Not bad if you compare to the price of a new inverter.

11 minutes ago, ErichK said:

TSP says +-R3k for refurbished motherboard. Not bad if you compare to the price of a new inverter.

Yep, thats good, as long as they provide a half descent warranty with the refurbished board. 

2 months they said, so only half decent.

Edited March 4, 20233 yr by ErichK

Not sure if this is the best place to start/continue my query, but:

I inherited my son in jhb's SunPays 5kVA inverter when he upgraded his system to a better(?) LuxPowerTek system with solar panels etc.

TSP system worked OK by me till we had 2 days without power whereafter it refused to start. I had the batteries charged and after much fiddling I managed to get the system to start.

A few months later samething happened but this time I could get the inverter to start so my son sent me a new LuxPowerTek which immediately started and is still running beautifully! 🤞 

Now: I have this TSP inverter that seems to need a new relay, sitting in my garage where I am sure it can be fixed and be worth a few R's?

I am in Cape Town. Any suggestions? Or should I ship it to Jhb where I have been given a few names by TSP that can fix it?

Thanks!!

TSP Techie: "Daai lyk soos n faulty relay op die inverter moederboard. Die relay op die inverter se moederboard sal moet vervang word."

"Ek het vir TheSunPays gekontak en die tegniese ou daar Ruaan het my raad gegee. Hy ken daardie simptoom, en hy sê dis tipies die relay of die relay drive circuit. 

Hy sê mens kan enige technician kontak wat 5kW Mecer of Kodak inverters regmaak. Hy ken net mense hier bo in Gauteng, maar niemand in Kaapstad nie."

"Dit is korrek. Enige tegniekus wat aan daai tipe inverters werk behoort die relay te kan vervang. Ek ken ongelukkig ook net technicians hier in Gauteng, maar ek weet n paar van hulle maak gebruik van courier dienste"

Hi ErichV, I'm going to send mine up to TSP at some point when budget allows.

On 2024/02/18 at 3:27 PM, ErichK said:

Hi ErichV, I'm going to send mine up to TSP at some point when budget allows.

Hi, any luck so far? 

I still have mine down in Ctn boxed catching dust but I  am sure it is worth a few RRR once "fixed" 🤔 

TSP is not supported outside Gauteng! 😢 

Is there anyone from Ctn reading this that can give advice?

Thanks

40 minutes ago, ErichV said:

Hi, any luck so far? 

I still have mine down in Ctn boxed catching dust but I  am sure it is worth a few RRR once "fixed" 🤔 

TSP is not supported outside Gauteng! 😢 

Is there anyone from Ctn reading this that can give advice?

Thanks

If it is only a known relay that failed any inverter repair tech should be able to fix it. No need to get to the seller in Gauteng. 

I opened it up today and replaced the 2 x 1000uF caps on the mainboard that are usual suspects in these inverters. But it did not fix it. Inverter powers up, but then it doesn't start inverting. No relay clicks. Just shuts down again after a minute or so. I'll start pulling out relays and check if there are any faulty ones. Maybe I'll replace all the caps around that power supply circuit.

Many I should ship you this one as well so that you at least have volume to work with!! 🤔 🤔 🤔 

But thanks for keeping me posted! I really appreciate it!! 🙏 🙏 🙏 

8 hours ago, ErichK said:

I'll start pulling out relays and check if there are any faulty ones.

That seems poor value for effort to me. I'd first sort out why the battery voltage is collapsing to 32V. Can you put a current clamp meter on a battery wire? 

My guess is that IGBTs are shorting the DC bus. 

Hi Coulomb, yeah I had that same thought, it was fun though. I can think of worse ways to waste my time with. I should have mentioned that the battery voltage didn’t drop this time. Stayed at 52V. The inverter just switched off. No clicks or beeps or anything. To test I used my battery while it was connected to my other inverter. The other inverter didn't sshow any indication of an issue when I switched the faulty one on.

I can hear relays switching when my working inverter starts up, with this one there are no sounds. Do you think it might be a relay or relay drive circuit?

Edited March 23, 20242 yr by ErichK

1 hour ago, ErichK said:

Do you think it might be a relay or relay drive circuit?

It's certainly possible, but it seems low on the list of likely suspects. I'm now thinking that it might be the main power supply now, since it can switch off with no sound of the relay connecting. Perhaps go a little deeper down the electrolytic capacitor list?

Will do and let you know. Probably only next weekend though. 

I haven't removed and tested all the capacitors yet. I just tested the relays I could find and they all work.

I could carry on replacingnparts and hoping for the best. But as a former technician, I don't believe that wont be productive time.

I don't have all the test equipment and bench like in my technician days so I'm at the end of what I can test without powering up the boards and taking measurements.

I'll have to make another plan.