Sterling inverter tripping out

[Chris T]

Hello all,

 

Having spent most of this lovely day bent double in the engine room, hubby is out of ideas and I'm hoping someone may have some suggestions.

 

We have a Sterling 3 in 1 pure sine wave inverter / charger which although we use very little 240v items, hasn't been any problem until now. 

 

In use a charger either on shoreline or from the alternator, the voltage shown on the LED rises quite quickly to around 16 volts then trips out with an 'over voltage' warning.

 

We have 4 domestic 110 batteries just over a year old and a starter battery (although suspect that we don't really need 4 as we don't use many appliances) which haven't given any indication of being flat and show 12.7 / 12.8 after a few days completely rested (tested with a multimeter).  Recent service also tested and said the batteries were good. 

 

Terminal connections seem fine. 

 

Any ideas gratefully received, thank you

[Tracy D'arth]

How do you use the charger from the alternator on the engine?

 

Does it trip only when the engine is running?

 

Does it work as an inverter to provide 240v from the batteries?

[Richard10002]

23 minutes ago, Chris T said:

We have a Sterling 3 in 1 pure sine wave inverter / charger which although we use very little 240v items, hasn't been any problem until now. 

 

In use a charger either on shoreline or from the alternator, the voltage shown on the LED rises quite quickly to around 16 volts then trips out with an 'over voltage' warning.

 

What is the actual model name of the inverter charger.

 

I used to have a Sterling Pro Combi S, so know a little bit about them, although it didnt have an LED readout of the voltage, so probably yours is a different model.

[Chris T]

28 minutes ago, Tracy D'arth said:

How do you use the charger from the alternator on the engine?

 

Does it trip only when the engine is running?

 

Does it work as an inverter to provide 240v from the batteries?

1. Not sure what you mean, sorry.  Just when the engine is running and the sterling is switched on.

 

2. No, it trips when the engine isn't running and whether or not the shoreline is connected, when it's in charger mode.

 

3. Yes, and it seems to work fine in inverter mode.

 

Thanks

 

[Chris T]

25 minutes ago, Richard10002 said:

 

What is the actual model name of the inverter charger.

 

I used to have a Sterling Pro Combi S, so know a little bit about them, although it didnt have an LED readout of the voltage, so probably yours is a different model.

The booklet covers DAI 1500 C, DAI 3000 C and DAI 1500 C. I'll need to check the paperwork at home.  Pic attached if any help.

 

Thank you. 

[Tony Brooks]

Any solar? If so then if the batteries have been turned off or disconnected without isolating the panels the solar controller may have reset itself to 24 volts so is now delivering an excess charging voltage the Sterling detects and trips out.

[Chris T]

4 minutes ago, Tony Brooks said:

Any solar? If so then if the batteries have been turned off or disconnected without isolating the panels the solar controller may have reset itself to 24 volts so is now delivering an excess charging voltage the Sterling detects and trips out.

Nope, no solar. 

[Tony Brooks]

1 hour ago, Chris T said:

In use a charger either on shoreline or from the alternator

 

I don't understand this bit unless your alternator is actually a Travelpower that produces mains voltage to feed the charger part of the inverter. An ordinary alternator has no need for a charger to be involved in battery charging.

 

For typical lead acid batteries 16 volts from whatever source is definitely over voltage unless the charge source is doing an equalization charge. It sounds like the inverter/charger is at fault but most of them these days use digital electronics so see if the manual tells you how to do  a full reset to factory settings.

[Chris T]

We thought that the unit would need to be on to charge the batteries on shoreline and also when out and about running the engine, but sounds like this isn't the case, so that's one thing learnt thank you. 

 

The manual tells you what the factory settings are but not how to reset to them. To be honest, we are struggling to follow the manual. 

 

 

We thought that the unit would need to be on to charge the batteries on shoreline and also when out and about running the engine, but sounds like this isn't the case, so that's one thing learnt thank you. 

 

The manual tells you what the factory settings are but not how to reset to them. To be honest, we are struggling to follow the manual. 

 

The indicator for equalising isn't lit up if that means anything.

 

 

Edited June 14, 2022 by Chris T
Added note about equalising.

[Tony Brooks]

2 minutes ago, Chris T said:

We thought that the unit would need to be on to charge the batteries on shoreline and also when out and about running the engine, but sounds like this isn't the case, so that's one thing learnt thank you. 

 

 

I can't be 100% sure that this is correct because there is a device that typically replaces one of the alternators on a twin alternator boat or the only alternator that in the end produces 240V AC. These would normally charge via a mains battery charger or inverter charger. Just to confuse the issue the bit on the engine looks almost identical to an ordinary alternator. It is a sort of umbilical cord that connects the "alternator" to a black or silver metal box that shows it is a Travelpower. I am not sure that you are experienced enough to tell the difference.

 

Turn the inverter/charger off and run the engine at about 1200 rpm and see what happens. If you are able also monitor the charging voltage. I would expect it to "top out" at 14.4 to 14.6 volts. If it does then it points to a faulty inverter/charger.

[Chris T]

Thanks for your replies but we've given up for today and headed home so will have a look at the rest of the boat paperwork and will get back and try again asap. 

 

We definitely have two 12 volt alternators and we've had no battery problems when out and about. Life was much easier when we had a boat where everything was 12 volts

 

[Tony Brooks]

16 minutes ago, Chris T said:

We definitely have two 12 volt alternators and we've had no battery problems when out and about.

 

That strongly suggests it is the inverter/charger that is playing up.

 

Carefully check the wiring diagrams just in case it has a sense wire back to the batteries, this is unlikely, but you never know. If a sense wire gets loose terminals, dirty terminals, falls off, or goes high resistance the charger will not be able to measure the charging voltage, so it usually goes high - often too high. However, because of the very thick 12v cables needed for the inverter, few, if any use a sense wire. Just a long shot worth checking.

[Chris T]

Hubby thinks there may be a sensor of some sort so will check that out.

 

Thanks for your replies, we really appreciate it. 

[Tony Brooks]

29 minutes ago, Chris T said:

Hubby thinks there may be a sensor of some sort so will check that out.

 

Thanks for your replies, we really appreciate it. 

Possibly a battery temperature sensor, but I would expect that to make only fractions of a volt difference, not about 1.5 volts.

[Chris T]

8 hours ago, Richard10002 said:

 

What is the actual model name of the inverter charger.

 

I used to have a Sterling Pro Combi S, so know a little bit about them, although it didnt have an LED readout of the voltage, so probably yours is a different model.

The Sterling wasn't fitted in the boat from new so the actual model isn't mentioned in the boat manual or anywhere else in the paperwork unfortunately. All I have is the Sterling manual that, as I mentioned, covers a few different models. 

[Tony Brooks]

9 hours ago, Chris T said:

All I have is the Sterling manual that, as I mentioned, covers a few different models. 

 

And having found one online it did not seem to have the voltage tables for the different battery type settings, only the maximum and minimum voltages for each setting. I did notice that it gave an equalization voltage of (from memory) up to 15.5V, but I could not find any info about stopping equalization so wonder if it is stuck in equalize mode, but it's monitoring circuits don'tr know.

 

I think a call to Sterling Technical might help .

[Chris T]

Thanks, the equalization LED indicator isn't lit up but maybe it's trying to do something like that.

 

And there are no sensors connected, he had seen the temperature sensor mentioned in the manual but have checked underneath the unit today. 

 

We will try calling Sterling although I imagine knowing the model would help! 

 

Thank you again for your time.

 

 

[Tracy D'arth]

18 minutes ago, Chris T said:

Thanks, the equalization LED indicator isn't lit up but maybe it's trying to do something like that.

 

And there are no sensors connected, he had seen the temperature sensor mentioned in the manual but have checked underneath the unit today. 

 

We will try calling Sterling although I imagine knowing the model would help! 

 

Thank you again for your time.

 

 

Surely the model number is on the top right of the front panel?  Can't quite read it on the photo'.

[Chris T]

No, that's just the CE marking on the top right. 

[Tracy D'arth]

35 minutes ago, Chris T said:

No, that's just the CE marking on the top right. 

It will be on it somewhere.  Don't phone Charles without it, he may get cross!

[Chris T]

Well.... further contortions and photos in virtually inaccessible places to look for a model number resulted in us peeling off a big sticker on the back of the unit. Not only did this give instructions on how to restore factory settings, but a diagram that matched the inverter/charger, unlike those in the manual. 

 

Followed these instructions and although it tripped immediately after turning back on, it then started to behave and give readings as we'd expect. We are going to go back tomorrow and test it for longer in the various settings, but we are cautiously optimistic. 

 

And the model number was on another sticker underneath the one we peeled off! 

 

Fingers crossed and thanks for all the replies, much appreciated.

 

 

[Tracy D'arth]

👍

[Chris T]

Well, today the Sterling has behaved as expected on all settings, so it's looking like all is well.

 

Comparing the settings, the battery indicator was previously set as 'open lead acid', the factory setting was 'AGM sealed'. The previous owner had 'wet' batteries which we have replaced, so we're not sure if the setting has somehow been changed recently, or whether the Sterling was happy with the sealed batteries on the 'open lead acid' setting until recently (I believe they behave differently) perhaps as they've become older. Anyway, we seem to be back in business.

 

Thanks again for taking the time to reply.

[Tony Brooks]

Many thanks for the feedback. Pleased a factory reset seems to have solved it.