Beta Genset high voltage issue

[Steve56]

11 hours ago, Tasemu said:

 

Its strange, I have an SL105 but upon inspection I cannot see an AVR located on the top as pictured here, instead i just see wires coming out of a hole in the top. and into the breaker, then out to the sockets.

The AVR is no 14 on the diagram. You will need to remove the plastic end cover to access it. Normally they have a small potentiometer on them to allow for voltage adjustment. Firstly though you will need to ensure engine speed is correct and alternator is giving around 52 Hz off load.

[Tasemu]

7 hours ago, Steve56 said:

The AVR is no 14 on the diagram. You will need to remove the plastic end cover to access it. Normally they have a small potentiometer on them to allow for voltage adjustment. Firstly though you will need to ensure engine speed is correct and alternator is giving around 52 Hz off load.

 

The end cap of the alternator appears to push up and into the insulation on the side of the acoustic box. I'll try to have a proper look to see if i am able to access the screws to remove the cap. Looks really tight though. 

[Eeyore]

16 minutes ago, Tasemu said:

 

The end cap of the alternator appears to push up and into the insulation on the side of the acoustic box. I'll try to have a proper look to see if i am able to access the screws to remove the cap. Looks really tight though. 

You will have to dismantle the end of the acoustic box to get to the circular end cover; it requires a clearance of at least its own length to remove it.

[Steve56]

1 hour ago, Tasemu said:

 

The end cap of the alternator appears to push up and into the insulation on the side of the acoustic box. I'll try to have a proper look to see if i am able to access the screws to remove the cap. Looks really tight though. 

Yes if I remember correctly they are done this way so they can get cool air. It will either end up at a louvred panel at the back of the housing or possibly go into a plenum chamber. Either way you will need to take housing appart to get good access.

[GUMPY]

Set the engine RPM first before messing with the AVR. If you don't you are on a hiding to nothing.

[Tasemu]

18 minutes ago, Loddon said:

Set the engine RPM first before messing with the AVR. If you don't you are on a hiding to nothing.

 

I definitely will, i got the old test certificate on installation with the hz i should aim for

46 minutes ago, Steve56 said:

Yes if I remember correctly they are done this way so they can get cool air. It will either end up at a louvred panel at the back of the housing or possibly go into a plenum chamber. Either way you will need to take housing appart to get good access.

 

Cheers, i'll take a look at it soon! For now i've ripped out the new multiplus and gonna return it. deal with the victron problem another day. Generator first.

[TheBiscuits]

8 minutes ago, Tasemu said:

For now i've ripped out the new multiplus and gonna return it. deal with the victron problem another day

 

Is there actually a problem with the multiplus?  If it's input is so far off spec it might be working *exactly* as it should!

[Tasemu]

8 minutes ago, TheBiscuits said:

 

Is there actually a problem with the multiplus?  If it's input is so far off spec it might be working *exactly* as it should!

 

Maybe it is, but that doesn't really matter if i'm unable to get it working with my generator. I'm nervous about taking it to pieces to see if this AVR is even adjustable. Then i'm not sure if i'll cause more damage than i fix by fiddling with it. So for the very short term im going to return it and look at non-victron options so I can cook food and charge. My smaller sterling charger works no worries. 😓

[Tracy D'arth]

All a waste of time and effort then?

[Tasemu]

1 minute ago, Tracy D'arth said:

All a waste of time and effort then?

 

Hmm.. depends. I definitely learned a lot about my generator, and debugging victron equipment. I do plan on working on the generator to attempt to get it back to proper spec. However i'm going to take it slow and calculated. Buy this tacho meter, buy a multimeter that can read frequency. Make more room for working on the alternator end of the genny etc. Then if i'm really confident that its working properly (and i dont need to do a full avr replacement or something). I may look into the multiplus again.

[IanD]

5 minutes ago, Tasemu said:

 

Maybe it is, but that doesn't really matter if i'm unable to get it working with my generator. I'm nervous about taking it to pieces to see if this AVR is even adjustable. Then i'm not sure if i'll cause more damage than i fix by fiddling with it. So for the very short term im going to return it and look at non-victron options so I can cook food and charge. My smaller sterling charger works no worries. 😓

Multiplus spec for AC input is 45Hz-55Hz 187V-265V AC. If you have 260V at 45Hz then the frequency is probably what is kicking the MP offline, not the voltage.

 

TBH you could also be running the risk of appliance damage with such low frequency *and* high voltage together, any internal transformers may saturate and draw higher than normal current...

[Tasemu]

I went searching for a spare AVR, but i guess they dont make them anymore?

[IanD]

1 minute ago, Tasemu said:

I went searching for a spare AVR, but i guess they dont make them anymore?

Did you ask Beta?

[Tasemu]

1 minute ago, IanD said:

Multiplus spec for AC input is 45Hz-55Hz 187V-265V AC. If you have 260V at 45Hz then the frequency is probably what is kicking the MP offline, not the voltage.

 

TBH you could also be running the risk of appliance damage with such low frequency *and* high voltage together, any internal transformers may saturate and draw higher than normal current...

 

I came to this conclusion also. As when i raised the frequency it also pushed the voltage slightly higher and was giving me high ac input disconnection errors. So i need to tackle this rpm issue first, then look at the voltage, which i'm very confident will be much too high and also jumping around. Could be an adjustment needed to the AVR, or a full replacement.

Just now, IanD said:

Did you ask Beta?

 

Yeah they said they don't make them anymore so can't offer support for parts/replacements

[IanD]

8 minutes ago, Tasemu said:

 

I came to this conclusion also. As when i raised the frequency it also pushed the voltage slightly higher and was giving me high ac input disconnection errors. So i need to tackle this rpm issue first, then look at the voltage, which i'm very confident will be much too high and also jumping around. Could be an adjustment needed to the AVR, or a full replacement.

 

Yeah they said they don't make them anymore so can't offer support for parts/replacements

 

The fact that you said "voltage is 260V-270V, sometimes jumps to 240V) suggests you might have a dodgy voltage sense connection somewhere -- when it's good the AVR sets the output to 240V, when it's bad the AVR thinks the voltage is too low so jacks it up to the maximum, presumably 260V/45Hz would then mean something like 290V/50Hz.

 

All you would have to do is find this dodgy connection, for example by attaching a DVM to the output and wiggling wires/connections/thingies to see if you can find something that makes the output voltage go back to 240V -- and then fixing the bad connection. Preferably without electrocuting yourself... 😉

Edited December 6, 2022 by IanD

[GUMPY]

11 minutes ago, Tasemu said:

I went searching for a spare AVR, but i guess they dont make them anymore?

You don't know there is anything wrong with the AVR yet.

Set the frequency first.

Then look at the AVR if it hasn't settled down

The multiplus is not at fault it is protecting itself. Other chargers/ combis do not have this protection and just go bang instead.

[Tasemu]

6 minutes ago, IanD said:

 

The fact that you said "voltage is 260V-270V, sometimes jumps to 240V) suggests you might have a dodgy voltage sense connection somewhere -- when it's good the AVR sets the output to 240V, when it's bad the AVR thinks the voltage is too low so jacks it up to the maximum, presumably 260V/45Hz would then mean something like 290V/50Hz.

 

All you would have to do is find this dodgy connection, for example by attaching a DVM to the output and wiggling wires/connections/thingies to see if you can find something that makes the output voltage go back to 240V -- and then fixing the bad connection. Preferably without electrocuting yourself... 😉

 

I'll give this a shot too, whats a DVM by the way?

3 minutes ago, Loddon said:

You don't know there is anything wrong with the AVR yet.

Set the frequency first.

Then look at the AVR if it hasn't settled down

 

I will do this once I get the kit to measure RPM and Hz thanks!

[IanD]

Just now, Tasemu said:

 

I'll give this a shot too, whats a DVM by the way?

Digital Volt Meter -- DMM (Digital Multi Meter) set to ACV (Alternating Current Voltage) range 😉

[Eeyore]

The maintenance requirements are quite simple:

"The SL model alternator similarly requires no regular mechanical maintenance. It is, however, fitted with slip-rings and brushgear which require regular attention.
Inspect brushes and sliprings at 500 hour intervals. Replace brushes when they are worn to a depth of 8 mm. The new brush should be bedded using a medium grade abrasive cloth. If the sliprings are pitted or badly marked the rotor should be removed and the sliprings lightly skimmed.
The alternator must periodically be inspected and any accumulation of dirt or oil must be removed. Air inlet and outlet openings must be kept unobstructed."

An accumulation of carbon dust from the brushes (normal wear) can cause some interesting symptoms, depending on where it settles.

[Eeyore]

Did you use a small load, say a 60w lamp, whilst testing? This seems to settle things down a bit. I've experienced units that displayed a harmonic frequency on the meter when off load. The worst one had sheared the screws holding the stator coils to the frame allowing them to rotate; with only the cable connections (briefly) holding everything in place! 

[Tasemu]

19 minutes ago, Eeyore said:

Did you use a small load, say a 60w lamp, whilst testing? This seems to settle things down a bit. I've experienced units that displayed a harmonic frequency on the meter when off load. The worst one had sheared the screws holding the stator coils to the frame allowing them to rotate; with only the cable connections (briefly) holding everything in place! 

 

I did use small medium and large loads to test with the multiplus, usually it was able to stabilise it enough to enter charging mode, but never for long. It would always click back to inverting after a few seconds/minutes.

[jonathanA]

On 06/12/2022 at 11:54, Tasemu said:

 

I came to this conclusion also. As when i raised the frequency it also pushed the voltage slightly higher and was giving me high ac input disconnection errors. So i need to tackle this rpm issue first, then look at the voltage, which i'm very confident will be much too high and also jumping around. Could be an adjustment needed to the AVR, or a full replacement.

 

Yeah they said they don't make them anymore so can't offer support for parts/replacements

That's a bit unhelpful. Most of these alternators use one of two avrs one is rectangular and the other is curved they are are usually a couple of quid from China delivered in 4 weeks or 15 quid from someone with them in the UK for next day delivery....  you just need to know the output rating of your generator. (E.g 2.5KVA). 

 

You will need to have a look at what's fitted to yours when you can access it. If you have never changed the brushes then that could be the problem.certainly worth checking them when you are in there.  Again chinese versions are available for naff all money I usually just order a few as they are a common problem on the ubitous cheap  Chinese 2.0-3.0 kva petrol gennies.

[Tasemu]

21 hours ago, jonathanA said:

That's a bit unhelpful. Most of these alternators use one of two avrs one is rectangular and the other is curved they are are usually a couple of quid from China delivered in 4 weeks or 15 quid from someone with them in the UK for next day delivery....  you just need to know the output rating of your generator. (E.g 2.5KVA). 

 

You will need to have a look at what's fitted to yours when you can access it. If you have never changed the brushes then that could be the problem.certainly worth checking them when you are in there.  Again chinese versions are available for naff all money I usually just order a few as they are a common problem on the ubitous cheap  Chinese 2.0-3.0 kva petrol gennies.

 

That is ideal, cheers! I'm going to take it apart this weekend to see

[Tracy D'arth]

22 hours ago, jonathanA said:

That's a bit unhelpful. Most of these alternators use one of two avrs one is rectangular and the other is curved they are are usually a couple of quid from China delivered in 4 weeks or 15 quid from someone with them in the UK for next day delivery....  you just need to know the output rating of your generator. (E.g 2.5KVA). 

 

You will need to have a look at what's fitted to yours when you can access it. If you have never changed the brushes then that could be the problem.certainly worth checking them when you are in there.  Again chinese versions are available for naff all money I usually just order a few as they are a common problem on the ubitous cheap  Chinese 2.0-3.0 kva petrol gennies.

Try generatorguru.com

[Tasemu]

Ok so i finally have an update for this thread. Through much nightmare I was able to disassemble the the acoustic box from around the generator and gain access to the end cap, which when removed allows access to the AVR and brush assembly. before changing anything I did the following tests with the following results.

 

1: Ran the generator as-is and off-load, then measured the Hz / Volts. Result was 45hz @ 260v.

2: Adjusted the engine speed carefully to bring the Hz up to 50.8hz off-load. Resulting voltage was 290V.

3: stopped the engine and adjusted the AVR voltage adjustment potentiometer down a half turn before re-starting. Result was 290v.

4: stopped the engine and adjusted the AVR voltage adjustment potentiometer to its minimum value (full ani-clockwise) before re-starting. Result was still 290v.

 

Notes: Brushes appeared to be in decent condition with enough material left to make good contact. One of the slip rings was slightly worn to the touch but didn't appear to be significant.

 

Reading previous posts on here, i'm tempted to guess that my AVR might be busted and a new one required. The AVR is a Markon AVR 036-245. I'm not sure if it is still possible to get one of these, or maybe there are other models that might fit?

 

Thanks in advance for any help!