Inverters

[Dockhead]

Originally Posted by s/v Beth

That's all nice about vitron, but who makes the most bombproof sine wave inverter?

Maybe Newmar? But they don't seem to make a modern charger/inverter with power boost etc.

I've heard very good things about the Sterling inverters; likewise no modern charger/inverter.

I am amazed we've never heard anything about Victron's main rival, Mastervolt. I would expect that this gear - also made in the Netherlands; also rather expensive -- must be pretty good. It's original install in Oysters.

[Dockhead]

Originally Posted by colemj

Yes, the Victron has two circuits - one 50A primary transfer-switched circuit and the other a 16A non-transfer switch (load shedding).

For us, the problem is in implementation. I'm not interested in the load sharing, because our inverter and shore power run the AC and water heater just fine without help. However, if I run those circuits through the primary circuit on the Victron, then if shore power goes out (a extremely common occurrence in the few marinas we have been in) or the generator quits or trips its circuit, then all of that load hits the batteries. If one is not right there staring at the panel when it happens, then those batteries will be run flat in no time.

This doesn't make sense to me.

On the other hand, 16A isn't enough to run those high output devices through the non-transfer switched circuit, and that circuit isn't load-sharing. So it is useless to us.

Instead, we use the 50A transfer switch circuit on the low load side of the AC panel and
leave the high load side unconnected to the inverter.

What we would ideally like is a transfer-switched circuit to handle the low load side, and a non-transfer switch power sharing circuit for the high load side.

In other words, when the power is cut, the low loads transfer to the inverter and the high loads get dropped. And when the power is on, the high loads can use the power-assist feature.

Of course, the user manual is written in Sanskrit and is printed using 3pt font (seriously - the whole manual is a 4"x3"x1" book with tiny, tiny type), so it is possible that it can be set up like I want, but I have not figured out how to do so.

As an aside, Victron supplies the worse documentation in the most obscure descriptions and language you will find in any manufacturer. I have met power engineers who work constantly with Victron products who still struggle with the manuals.

Mark

Mark, if you wire up your high load circuits bypassing the Victron, you will lose the benefit of the load limiting feature -- one of the main reasons to have this inverter in the first place.

If 16 amps is not enough (that's about 3.6kW -- plenty for us), then why don't you just wire up a relay?

So power the high current loads from the main panel as usual -- so the actual power comes via the main circuit of the inverter/charger and the 50 amp transfer switch. But put in a relay after the breaker which will interrupt the power to those loads you want shut down in case of a shore power fault, in case the 16 amp load shedding circuit is de-powered.

It would need a normally open relay which is closed by power supplied from the 16 amp load shedding circuit. Should work fine.

Come to think of it -- by George -- I could wire mine up that way. Might be simpler than installing a separate breaker and power feed. I would just need a light cable to take enough power from the load shedding circuit to power the relay. Hmmm.

[Rick R]

Originally Posted by colemj

Yes, this is how our electrical system is designed and implemented. However, it doesn't help in taking advantage of some of the Victron options. I don't think Victron has thought out their power sharing and no-transfer auxiliary systems well. I cannot figure out how to wire it so that the inverter has no chance at all of putting the high loads on the batteries if the shore power or generator is cut. Why anyone would want that risk is also something I cannot figure out.

On the other hand, I could be missing something completely obvious.

Mark

The Victron has two AC power terminals. Terminal A is on all the time, using battery power if the shorepower or generator is not available. Terminal B does not draw from the batteries if there is no shorepower. It is live only when shorepower or generator power is available.

Wire the air conditioner, elec hot water heater, and any other large power users to terminal B.

There are two ways to rig a warning if shorepower goes off. Most battery monitors have a warning of low battery power. Often this feature can be used for auto generator start, but we just wired in a bright red LED instead. Or, an even simpler way is to install a cheap hardware store power interruption warning light to terminal B

[exMaggieDrum]

Originally Posted by colemj

Yes, this is how our electrical system is designed and implemented. However, it doesn't help in taking advantage of some of the Victron options. I don't think Victron has thought out their power sharing and no-transfer auxiliary systems well. I cannot figure out how to wire it so that the inverter has no chance at all of putting the high loads on the batteries if the shore power or generator is cut. Why anyone would want that risk is also something I cannot figure out.

On the other hand, I could be missing something completely obvious.

Mark

I may not have been clear enough, or I don't understand what you are saying, but I don't think you have wired it the way I was trying to describe. The way I described it does not take advantage of some of the Victron options that some have described here. I don't know the Victron inverter so can't speak to that. But the way I suggested the inverter looks like a load to the incoming shorepower, along with any high load circuits, such as a hot water heater. Neither of them would work unless shorepower is available to the panel. The inverter powers the low load circuits (and charges if that is on). It is as if you had two separate AC panels, one for the inverter and high loads, and one for the low loads. When shorepower is not available the high loads and the charging circuit of the inverter/charger will not operate - at all but the load loads would be from the inverting function. If shorepower is available the high loads (e.g. water heater) have AC power available and so does the inverter so it can pass through the AC to the load load circuit breakers and loads. The inverter can power the low loads via the inverter/battery side when shore power is not available.

From what someone else said the Victron may be able to split all this with its A and B terminals but I can't speak to that. I would certainly want to clearly understand how it works before using it. I would not, under any circumstances, wire a hot water heater to an inverter. It would be a big risk. A genset would be a better option IMHO.

Also, watts are equal to volts x amps. So 16 amps AC x 120 volts AC = 1920 watts, or about 2kW.

[exMaggieDrum]

Originally Posted by Dockhead

Mark, if you wire up your high load circuits bypassing the Victron, you will lose the benefit of the load limiting feature -- one of the main reasons to have this inverter in the first place.

If 16 amps is not enough (that's about 3.6kW -- plenty for us), then why don't you just wire up a relay?

So power the high current loads from the main panel as usual -- so the actual power comes via the main circuit of the inverter/charger and the 50 amp transfer switch. But put in a relay after the breaker which will interrupt the power to those loads you want shut down in case of a shore power fault, in case the 16 amp load shedding circuit is de-powered.

It would need a normally open relay which is closed by power supplied from the 16 amp load shedding circuit. Should work fine.

Come to think of it -- by George -- I could wire mine up that way. Might be simpler than installing a separate breaker and power feed. I would just need a light cable to take enough power from the load shedding circuit to power the relay. Hmmm.

You don't necessarily lose the power-sharing feature, you just only use it for the low loads. I would not recommend trying to power-share with a hot water heater but I might with a hair dryer. 16 amps AC is 1920 watt (19.2kW). If you have to put in a relay, then I think something is wrong. Way too complicated and not necessary from what I can see. The power shedding feature should be managed by the Victron. If it is not, then it is seriously flawed.

[exMaggieDrum]

Originally Posted by Rick R

The Victron has two AC power terminals. Terminal A is on all the time, using battery power if the shorepower or generator is not available. Terminal B does not draw from the batteries if there is no shorepower. It is live only when shorepower or generator power is available.

Wire the air conditioner, elec hot water heater, and any other large power users to terminal B.

There are two ways to rig a warning if shorepower goes off. Most battery monitors have a warning of low battery power. Often this feature can be used for auto generator start, but we just wired in a bright red LED instead. Or, an even simpler way is to install a cheap hardware store power interruption warning light to terminal B

A better place to put a warning light/alarm would be at the circuit breaker for the incoming AC from either the shorepower or genset, but you could use the B terminal as well. I prefer to put the warning circuit at the source of the problem. It is easier to diagnose there. It would have to be battery powered though since you would not have AC at that point (unless you powered it from the inverter output). In any case, losing AC for the big loads would be pretty obvious in most cases but nothing wrong with an indicator to highlight it. If you have to wait for a low battery warning, then the setup is not ideal. You would want to prevent the batts from getting too low in the first place. Low batts can be a very serious problem that you might not be able to rectify at that time. And what a waste of battery energy and possible battery damage.

[Rick R]

Originally Posted by exMaggieDrum

A better place to put a warning light/alarm would be at the circuit breaker for the incoming AC from either the shorepower or genset, but you could use the B terminal as well. I prefer to put the warning circuit at the source of the problem. It is easier to diagnose there. It would have to be battery powered though since you would not have AC at that point (unless you powered it from the inverter output). In any case, losing AC for the big loads would be pretty obvious in most cases but nothing wrong with an indicator to highlight it. If you have to wait for a low battery warning, then the setup is not ideal. You would want to prevent the batts from getting too low in the first place. Low batts can be a very serious problem that you might not be able to rectify at that time. And what a waste of battery energy and possible battery damage.

The Victron battery monitor (and probably other brands as well) can be programmed to activate a warning at any battery state of charge. Ours is set to activate at 60% SOC as a reminder that I should start the generator soon. It is useful as a shore power warning because it should never activate while we are connected to shore power.

The reason I suggested a power interruption warning on inverter terminal B is so that it would warn of a malfunction of any part of the shore power circuit, not just the marinas feed. We do not have such an indicator, since a failure should be very obvious.

[Dockhead]

Originally Posted by exMaggieDrum

Also, watts are equal to volts x amps. So 16 amps AC x 120 volts AC = 1920 watts, or about 2kW.

Who uses AC power at 120 volts? Ick. We have, with the rest of the civilized world, 230 volts, so 3.6kW. I hope that the low-tech, low-voltage, 120 volt version of the Victron charger/inverter will support 32 amps. At exorbitant extra cost, of course

[Dockhead]

Originally Posted by exMaggieDrum

You don't necessarily lose the power-sharing feature, you just only use it for the low loads. I would not recommend trying to power-share with a hot water heater but I might with a hair dryer. 16 amps AC is 1920 watt (19.2kW). If you have to put in a relay, then I think something is wrong. Way too complicated and not necessary from what I can see. The power shedding feature should be managed by the Victron. If it is not, then it is seriously flawed.

Why would you want it only for low loads? It's high loads where it is really useful -- it will throttle back the charger to allow for other loads, and then throttle it back up when it's possible to do so. And if you are using all your shore power capacity, and want to run an electric kettle for a couple of minutes, the Victron will provide inverted power to do that, so that you don't need to manually switch things off lest you blow a shore power breaker somewhere. That's what it's made for, and it's wonderful. But it will only work if all your loads - big, and small -- are run through the Victron.

[goboatingnow]

As for robust inverters, I rate Studer very highly

Dave

[Garrettw]

Originally Posted by Dockhead

Who uses AC power at 120 volts? Ick. We have, with the rest of the civilized world, 230 volts, so 3.6kW. I hope that the low-tech, low-voltage, 120 volt version of the Victron charger/inverter will support 32 amps. At exorbitant extra cost, of course

Yes, the AC aux port is 32A on the 120V version in Victron's spec sheets.

[colemj]

Originally Posted by Garrettw

Yes, the AC aux port is 32A on the 120V version in Victron's spec sheets.

On our Multiplus 3000/120V, the AC aux port is 16A. The AC-1 port is 50A.

Mark