A/C causes genset to go offline momentarily

[jefndeb]

Looking for suggestions-

We have a Kohler 8k marune genset and while running our 16k dometic AC pack, (when at anchor,) i notice that each time the compressor kicks on, our Victron touch screen GUI indicates that our shorepower/Genset feed drops out for about 10 seconds and then comes back online.

The shorepower and/or generator feeds go thought the Victron Multuplus 3k Inverter/Charger as it normally is designed..

This "trip" seems to follow when the compressor cycles from off to on.

Is this an indication that the capacitors on out genset are going out?

Not really sure if these capacitors are used in a way to buffer a spike or not.

I'm not really to sure of I'm close on my thought pattern here but just wanted to ask for suggestions.

Would be glad to hear ideas.

Maybe its the water pump cycling on that doing this?

PS, Our Air Conditioning system is 240vac

Thanks,
Jeff

[s/v Jedi]

There isn’t a problem, it’s a setting. Let me think a bit about which one…

[s/v Jedi]

Originally Posted by s/v Jedi

There isn’t a problem, it’s a setting. Let me think a bit about which one…

Found it: Dynamic Current Limiter, set it to ON.

[wingssail]

Originally Posted by jefndeb

Looking for suggestions-

We have a Kohler 8k marune genset and while running our 16k dometic AC pack, (when at anchor,) i notice that each time the compressor kicks on, our Victron touch screen GUI indicates that our shorepower/Genset feed drops out for about 10 seconds and then comes back online.

The shorepower and/or generator feeds go thought the Victron Multuplus 3k Inverter/Charger as it normally is designed..

This "trip" seems to follow when the compressor cycles from off to on.

Is this an indication that the capacitors on out genset are going out?

Not really sure if these capacitors are used in a way to buffer a spike or not.

I'm not really to sure of I'm close on my thought pattern here but just wanted to ask for suggestions.

Would be glad to hear ideas.

Maybe its the water pump cycling on that doing this?

PS, Our Air Conditioning system is 240vac

Thanks,
Jeff

From what I read that 16KBTU AC will draw about 1500 watts but the start-up inrush can be several times that, which might exceed the pass-through of the Victron Inverter/Charger. It seems like the current is getting through but the Victron is complaining.

[smac999]

It’s possible the voltage or freq is going out of range when it serges. Causing the charger to stop passthrough

Is the ac connected to the inverter output or non inverter output? When it cuts out is the a/c getting inverted?

[rslifkin]

I see the same on my boat (A/C is not fed through the inverter). Basically, the dip in the generator voltage and frequency caused by the A/C starting happens so quickly that the Victron gear sees it as a power problem and flips to inverting for a moment, then decides the power is suitable and switches back. I don't run A/C on generator power very often, so I haven't really hunted for a fix.

[s/v Jedi]

No need to hunt for fixes, I posted the fix right above in the thread. I have confirmed this on multiple installations.

[rslifkin]

Originally Posted by s/v Jedi

No need to hunt for fixes, I posted the fix right above in the thread. I have confirmed this on multiple installations.

Dynamic current limiter will help if you're running the A/C through the Multiplus. But for a setup like mine where the A/C doesn't go through the Multiplus (and I have power assist disabled as well) I can't see how it would make any difference.

[s/v Jedi]

Originally Posted by rslifkin

Dynamic current limiter will help if you're running the A/C through the Multiplus. But for a setup like mine where the A/C doesn't go through the Multiplus (and I have power assist disabled as well) I can't see how it would make any difference.

The solution is for the OP. I read your post saying you have the same problem but now that I check it again, I see that it also says you don’t have the Multiplus between genset and A/C.

Yes, the surge from the A/C will be detected as an unsuitable power source. You can fix this by moving loads like A/C that you don’t want to power from battery to the OUT2 terminals on the Multiplus and changing the setting I mentioned.

The good thing about that change is that the Multiplus knows about the load of the A/C and it knows the maximum allowable load of the genset. It will reduce battery charging real quick during these events instead of overloading the genset, which is better for the systems.

[jefndeb]

Thanks very much for your suggestion, I just checked and I do have that option selected to on....

Also, it doesn't cycle when we are connected to dock power, so seems its something to do with the generator feed only...

Jeff

[s/v Jedi]

Originally Posted by jefndeb

Thanks very much for your suggestion, I just checked and I do have that option selected to on....

Also, it doesn't cycle when we are connected to dock power, so seems its something to do with the generator feed only...

Jeff

Shore power has an ample supply so it’s normal that it doesn’t show the problem.

So you have an 8kW genset. How many BTU is the A/C? I have an 18kBTU A/C on a 6kW Northern Lights genset and the setting fixes it.

The age of the genset, as well as what type of voltage regulator it has come into play. I have an electronic voltage regulator. You could observe voltage and current during the compressor start surge.

[jefndeb]

Ok,, yes the genset has 1030 hrs and its a 2005 model.
I was wondering if I don't see it drop offline on the 120v leg, seems to only be 240....or am I misunderstanding what I am seeing as the analog 120 v needle only bumps a little (when the ac cycles) but the victron shows that it got dropped momentarily ...

[rslifkin]

Originally Posted by jefndeb

Ok,, yes the genset has 1030 hrs and its a 2005 model.
I was wondering if I don't see it drop offline on the 120v leg, seems to only be 240....or am I misunderstanding what I am seeing as the analog 120 v needle only bumps a little (when the ac cycles) but the victron shows that it got dropped momentarily ...

That sounds like what I see as well. A quick flick, but enough to make the Multiplus drop off generator power for a moment. It's not that it goes out of range for long, but it's just enough (and happens very suddenly) that it thinks there's a power problem.

[s/v Jedi]

Originally Posted by rslifkin

That sounds like what I see as well. A quick flick, but enough to make the Multiplus drop off generator power for a moment. It's not that it goes out of range for long, but it's just enough (and happens very suddenly) that it thinks there's a power problem.

Exactly. When you have the UPS option enabled, this will be even more sensitive.