Shorepower cycle converters

[tanglewood]

Perhaps some of the confusion is because your drawing doesn't reflect how the Mass/Combi actually works. So your switched and unswitched circuit notations are likely to cause confusion.

Mastervolt has the concept of a Interrupted and uninterrupted output. The Interrupted output is wired directly to the AC input. The Interrupted output is "interrupted" when there is a loss of AC input. I'm assuming your red circuit for the HWH is the Interrupted output.

The Uninterrupted output is always active, powered either by the inverter or via pass thru of the input AC through an internal switch/relay. This is your black circuit.

So for the part of your drawing that represents the Mass Combi, there should only be one switch (the one on the input side on the left). And the red Interrupted circuit should be connected to the input side of the switch on the left.

[Catalysis]

Tangle wood,
We have two separate water heaters and tanks, one for each engine (both with electric elements) and they are wired separately.
The A/C units are cycle agnostic.
I don't understand why I won't have 6kw charging capacity (2.4 from chargemaster + 3.6 from Mass Combi #2) when utilizing 50hz - what am I missing?
Thanks for your input.


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[smac999]

Originally Posted by Catalysis

Tangle wood,
We have two separate water heaters and tanks, one for each engine (both with electric elements) and they are wired separately.
The A/C units are cycle agnostic.
I don't understand why I won't have 6kw charging capacity (2.4 from chargemaster + 3.6 from Mass Combi #2) when utilizing 50hz - what am I missing?
Thanks for your input.


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I understand the wiring

I'm was just questioning whether the combis can accept 50hz/60hz. I always thought inverter / chargers can't. and most people doing this way have charger units only and inverter only units for this reason. I know the chargers can, but they are charger only. the inverter output probably needs to sync up when switching back and forth and obviously the 60hz inverter output isn't going to sync with the 50hz shore. and it'll be pretty confused.

if it will accept and charge on both 50 and 60hz. and only invert on 60 then you are ok. but I find it strange that it'll charge and pass through 50hz and then invert 60hz when shore lost. you'd have to confirm with mastervolt.

if it does then you have 2 chargers and will be fine. if it doesn't you'll blow up the combi

[tanglewood]

Originally Posted by Catalysis

Tangle wood,
We have two separate water heaters and tanks, one for each engine (both with electric elements) and they are wired separately.
The A/C units are cycle agnostic.
I don't understand why I won't have 6kw charging capacity (2.4 from chargemaster + 3.6 from Mass Combi #2) when utilizing 50hz - what am I missing?
Thanks for your input.


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OK, sorry. Your comments have made me look more closely at the drawing, and I actually think what you have is pretty messed up. Here are comments:

- I though the black and red cricuits coming out of each inverter were the two outputs from the inverters and were how you are separating 50/60hz equipment from 60hz only equipment. Now I see the note that inverter 1 is for 60hz gear, and inverter 2 is for 50/60 gear. So I guess I don't understand what the red and black are, and the switches that you show internal to each inverter.

- Inverter 2 isn't going to behave as you expect. If you feed it 50hz power, it will ignore it. It will only use the input power if it meets it's criteria for acceptable 60hz power. So it will always be inverting on 50hz power, and never charging and never passing through 50hz to the loads. I think this is very different from what you are expecting.

- If you want the inverter 2 loads to get 50hz shore power when available, and inverter power otherwise, then you will need an external bypass relay.

- If you want more charging from 50hz power, you need more pure chargers - the inverters will only charge off 60hz.

- As drawn, there is really no difference between your 50hz and 60hz switch positions. In both cases the charger is always powered off shore plug 1. Inverter 1 is disconnected from shore power in the 50hz position, but it would always ignore it anyway. And inverter 2 is always connected to shore plug 2, but will always ignore it when 50hz. So those two switch positions accomplish nothing.

- In the gen switch position, you are not powering the charger. You might as well put it to work when the gen is running.

[Catalysis]

Hi Tanglewood,
Thanks for reviewing, according to Mastervolt the Mass Combi's will accept 50 or 60 cycle input and convert to 24v DC for battery charging so in 50 cycle service I will have both the Chargemaster and Combi #2 charging the batteries.
I agree the red lined circuit on the diagram is somewhat misleading - on each unit the switch is ganged with the supply side such that the Invertor does not feed the water heaters .
WRT the genset it is supplying 60 HZ which powers all users and both Master Combi's so the Chargemaster is not needed.



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[hoppy]

"Wine fridge" what a luxury

[tanglewood]

Originally Posted by Catalysis

Hi Tanglewood,
Thanks for reviewing, according to Mastervolt the Mass Combi's will accept 50 or 60 cycle input and convert to 24v DC for battery charging so in 50 cycle service I will have both the Chargemaster and Combi #2 charging the batteries.
I agree the red lined circuit on the diagram is somewhat misleading - on each unit the switch is ganged with the supply side such that the Invertor does not feed the water heaters .
WRT the genset it is supplying 60 HZ which powers all users and both Master Combi's so the Chargemaster is not needed.



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OK, that first statement is a big and important assumption that your system design is largely dependent on. I see what their specs say (45-65hz input range), but would be VERY surprised if it actually works that way. I expect it's more like 55-65 for 60hz operation, and 45-55hz for 50hz operation. I admit that I have never done an input frequency sweep on a Mass Combi to test what they will accept, but one of the objectives of an Inverter/charger is to provide consistent output power that meets some specification. I would be really, really surprised if a MassCombi configured for 60hz operation will accept 50hz input power, close the passthru relay, and feed 50hz power to the 60hz appliances on the output side. If I were you I'd insist on a first-hand verification of how it operates with 60 and 50 hz input power to confirm it does what you expect. It would really suck to build a system around that assumption and find it's wrong.

Re the red and black circuits, are the two switches on each inverter supposed to represent relays internal to the inverter, externally added relays, or some combination of both? I ask because the Mass Combi only has one relay, not two. If I had the schematic and Mass combi in front of me, I wouldn't know how you want it wired up, so I would guess what you mean.

[Catalysis]

Tanglewood,
Yes they are internally switched - I only showed them that way to make the drawing easier.
I fully agree with your caution to test everything - my drawing showed only a portion of the fully integrated Mastervolt system which includes not only the 120v system shown but also the 24v and 12v systems. The integrated system complete with system monitoring has been approved by Mastervolt and will be circuit tested at the shipyard, undergo a three day sea trial and finally be load tested and signed off by Mastervolt distributor before our first transatlantic trip.
Thanks again for your review .



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[tanglewood]

Originally Posted by Catalysis

Tanglewood,
Yes they are internally switched - I only showed them that way to make the drawing easier.
I fully agree with your caution to test everything - my drawing showed only a portion of the fully integrated Mastervolt system which includes not only the 120v system shown but also the 24v and 12v systems. The integrated system complete with system monitoring has been approved by Mastervolt and will be circuit tested at the shipyard, undergo a three day sea trial and finally be load tested and signed off by Mastervolt distributor before our first transatlantic trip.
Thanks again for your review .



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Sounds good. I'd be real interested in a follow up about how it works. What your describe is so different from how everyone else's inverters operate. All others qualify the input with fairly tight parameters, particularly on frequency, before they will switch over to it. It's typically +/- 3 to 4hz from the nominal which is 60hz in your case, and is to ensure that loads never see power that is too far off in voltage or frequency.

Where is the boat being built?

[Catalysis]

Tanglewood ,
We are building two nearly identical boats in South Africa.

Due to the combination of :
* 20 kW Lithium house banks - 24v
* High solar capacity (1.8kw) - two banks of 900w each with separate MPPT controllers.
* High output alternators (120v and 12v)
* Autostart genset

We bit the bullet and went all Mastervolt (except for Victron Auto-Isolation transformers) including their bus-systems monitoring BMS etc. In that way we have a single supplier to work with.

We have also tried to keep the redundancy theme in other systems:
* Twin 24v Spectra Watermakers
* Three a/c units with soft-start.
* Parallel 24v to 12v convertor's (12v for engine and genset)

The goal is flexibility and redundancy but with only a single switch to go from 60 to 50 cycles for ease of operator use. A tall order but I'll share our experience when we have transited to Carib in 1Q17.



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[tanglewood]

Sounds good. Our power system has similar objectives, though the implementation is different. But there are infinite perfectly good solutions to the problem.

My real point of curiosity is around the Mass Combi configured for 60hz operation, yet accepting and passing through 50hz shore power. That really raises an eyebrow, but you have done all the diligence I can imagine short of bench testing it. And it sounds like you have rallied the right Mastervolt reps. Technical info on MasterVolt products is nearly non-existent in the US, and all support inquiries get sent to their dealers who know even less. As a result I avoid them now. Plus, they don't have any good solutions for North American split phase power which is only the largest single market in the world. I'm not trying to be parochial and am not really a fan of our system, but the size of the market is the size of the market, all opinions aside. Victron suffers the same shortcoming.

[Catalysis]

Tanglewood,
I agree getting knowledgable reps is hard - hence my reaching out to the community.
If you send me your email info I'll share the full design with you.
The choice of Mastervolt was determined by finding the best technical marine resource in South Africa that the Dutch Engineers we're comfortable with.



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[tanglewood]

Originally Posted by Catalysis

Tanglewood,
I agree getting knowledgable reps is hard - hence my reaching out to the community.
If you send me your email info I'll share the full design with you.
The choice of Mastervolt was determined by finding the best technical marine resource in South Africa that the Dutch Engineers we're comfortable with.



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PM sent. I expect the Dutch connection to Mastervolt doesn't hurt.