Why Not Use AC Power for Thrusters and Windlasses?

[Dockhead]

Originally Posted by minaret

You just let me know when to dust off my grinder. I've hung my own shingle and have an ace crew who'd love a big build. Several of us worked with Janicki on BMW Oracle, for instance. I built Carl Schumacher's last design as well. Be happy to build you something big and beautiful in carbon!


BTW, sounds like a hell of an Arctic journey. Good luck, should be an amazing voyage!

OK, I'll keep it in mind!

Not carbon, though -- probably metal of some kind. Vessel should be workboat-like and very sturdy. Something you wouldn't mind bashing a bergy bit with.

[blackswan555]

I think it is over complicating things, But it can be done reasonably, Below I am talking in "European" eg 230v 1 ph, it can also be done in "American" , A lot of my experience is with outback equipment, Not the cheapest, But in my opinion the best, So that is what I am referring to, many manufacturers will offer the same features

Assuming you want a thruster of 7kw & can find a suitable AC 3ph model, You have an electric start generator 5ish kva min (1ph) & are installing a reasonable AC / inverter system,
Either one Outback 8k radion or two 3k VFX inverter chargers, 8 or 6 kw run, ( you can parallel more if you want, 27kw max on vfx) they will surge way past there & of course a reasonable set of batteries, That will give you your stable 230v "mains" The OB connects & starts to the gen when programmed, this can be on battery state of charge or if there is a large load (load start) AC changeover is seamless,
That should take care of the house systems,

Thruster, I would look for 3 phase, I would then use a VFD (variable frequency drive, long but good link below) with a VFD you can run a 3ph motor off single phase, You have soft, full torque variable start & direction, Variable speed up to 110% and can limit the current drawn if you want,

Drives Direct - Digital Phase Converters - How To Choose,

Tim

[Dockhead]

Originally Posted by blackswan555

I think it is over complicating things, But it can be done reasonably, Below I am talking in "European" eg 230v 1 ph, it can also be done in "American" , A lot of my experience is with outback equipment, Not the cheapest, But in my opinion the best, So that is what I am referring to, many manufacturers will offer the same features

Assuming you want a thruster of 7kw & can find a suitable AC 3ph model, You have an electric start generator 5ish kva min (1ph) & are installing a reasonable AC / inverter system,
Either one Outback 8k radion or two 3k VFX inverter chargers, 8 or 6 kw run, ( you can parallel more if you want, 27kw max on vfx) they will surge way past there & of course a reasonable set of batteries, That will give you your stable 230v "mains" The OB connects & starts to the gen when programmed, this can be on battery state of charge or if there is a large load (load start) AC changeover is seamless,
That should take care of the house systems,

Thruster, I would look for 3 phase, I would then use a VFD (variable frequency drive, long but good link below) with a VFD you can run a 3ph motor off single phase, You have soft, full torque variable start & direction, Variable speed up to 110% and can limit the current drawn if you want,

Drives Direct - Digital Phase Converters - How To Choose,

Tim

Well, that actually sounds pretty interesting. Maybe worth rethinking this.

It would be one step short of hybrid drive so maybe not worth doing all this without going all the way.

But I would do it slightly differently -- ganged Victron Multipluses will give three phase as well as single phase power.

I would combine that with a three phase generator (Northern Lights will make them on special order), say the 10kW one of theirs.

Then a LiFePo battery bank.

That would be capable of running a 10hp thruster on either generator or inverters, or both with only partial load on.

An alternative to an AC thruster would be a higher voltage DC one -- 32v or 48v. If the winches and windlass can also be sourced in that voltage, then that considerably increases the efficiency of the whole system. Just step down to 24v or 12v for the other DC gear on board.

I notice, by the way, that Lighthouse windlasses are available in 230v AC.

[blackswan555]

You can gang the OB's for 3 phase if you want but I have only ever converted 3ph back to single,( systems, generators & pumps) Problem comes with 3 ph, again ob but I think they are all similar, You can have your 9 kw 3ph but only have whatever one inverter is single, eg with the ob, you need 3 inverters but can only draw 3kw per phase, In practice unless you have predominantly 3ph motor loads, it is a pain in the ar%e, uses far more on standby, ( you have all 3 inverters running, if single they stage/sleep) also with your gen, 10kva 3 phase will only give you around 3kva per phase & the only thing you want 3 ph for is occasional use that can be "VFD'd, Also a quick think about shore power, Is 3 ph available everywhere ?

Tim

To add any 12 wire generator can be configured 1ph or 3 ph, if you convert a 3ph to a 1ph you will get 58% of the 3 ph rating

[blackswan555]

To add a bit more Do the Victron's have neutral / ground switching ? A 5 year guarantee ? Field serviceable ? eg you can change any one of the 3 boards in under an hour

Tim
Told ya I like OB lol http://outbackpower.com/downloads/do..._specsheet.pdf

[blackswan555]

I would combine that with a three phase generator (Northern Lights will make them on special order), say the 10kW one of theirs.
That would be capable of running a 10hp thruster on either generator or inverters, or both with only partial load on.

I think you may be a little close there, 10 hp is about 7.5kw with, the gen being 10KVA with a power factor of probably 0.8 it is really about 8,5 KW, If you do not soft start it depending on the motor diameter it could draw 5x it's run current (check LRA on motor, Locked rotor amps) Some "intelligent" control would be in order :-)

LifePo's, I know nothing much about, I did read somewhere that Tesla's 7kwh wall will only give a max of 2kw as a load ? I do not know how true that is, but needs taking into consideration if it is right

[Dockhead]

Originally Posted by blackswan555

To add a bit more Do the Victron's have neutral / ground switching ? A 5 year guarantee ? Field serviceable ? eg you can change any one of the 3 boards in under an hour

Tim
Told ya I like OB lol http://outbackpower.com/downloads/do..._specsheet.pdf

Im not married to Victron; it's just what I know. I will gladly look at those units. Are they sold in the UK? Do they do power boost?

Sent from my D6633 using Cruisers Sailing Forum mobile app

[blackswan555]

Sorry about the Victron bashing , I use a Spanish supplier, The UK listed is Renewable Energy Solutions | Wind and Solar Power | Wind & Sun, It was a few years back but I have dealt with them, Very helpful,

Edited to add,
Give the guy a call at drives direct, He is a bit old school when it comes to net, Prefers a call But what he does not know about VFD's and associated equipment is not worth knowing :-)
http://www.drivesdirect.co.uk/
Tim

[Cadence]

3ph, are we speaking pleasure boats or aircraft carriers?

[Dockhead]

Originally Posted by blackswan555

Sorry about the Victron bashing , I use a Spanish supplier, The UK listed is Renewable Energy Solutions | Wind and Solar Power | Wind & Sun, It was a few years back but I have dealt with them, Very helpful,

Tim

Bash away. I have had reliability problems with Victron gear, so would be glad to find something better.

I crawled around the Outback Power site, which is singularly unhelpful. Do these units have power boost, or not? What do they do, and how do they work? You can't figure it out from their site, and can't even download a manual as far as I can see.

[Colin A]

3Phase is becoming more common in Mega yachts. We did some 3 phase panels for an 85' last year. I have quoted down to 75' but they decided to stick with 100 amps of 240. The 85' only had 4 loads on 3 phase by the way, chiller,dive compressor, davit and bow thruster.

Also on gen size remember sailboats are a very small market (and shrinking at least in the US) Power boats over 35' almost all has a AC gen onboard (even the center consoles) Looking thru stuff we have built recently it looks like the new standard is 9-10kw for a 40' 12-15kw for 40-46' and anywhere from 15-20 on bigger boats.

[St. Elsewhere]

Originally Posted by Cadence

3ph, are we speaking pleasure boats or aircraft carriers?

I agree that 3 phase AC power is a bit much. Single phase AC has the disadvantage of very low torque on startup. For smaller boats DC electric seems best. Twin engine motor yachts do well with hydraulics. Mine has ample bow thruster power at idle from two pumps (one on each engine), plenty of windlass power, and good davit power with one engine running. 18 years on this equipment with no leak issues, and the hydraulic system reliability is better than my genset AC power.

[Cadence]

Originally Posted by St. Elsewhere

I agree that 3 phase AC power is a bit much. Single phase AC has the disadvantage of very low torque on startup. For smaller boats DC electric seems best. Twin engine motor yachts do well with hydraulics. Mine has ample bow thruster power at idle from two pumps (one on each engine), plenty of windlass power, and good davit power with one engine running. 18 years on this equipment with no leak issues, and the hydraulic system reliability is better than my genset AC power.

[Cottontop]

Kohler offers small (11kw) 3ph marine gen sets.

[blackswan555]

I crawled around the Outback Power site, which is singularly unhelpful. Do these units have power boost, or not? What do they do, and how do they work? You can't figure it out from their site, and can't even download a manual as far as I can see.

Power boost, ? not sure what you are referring to ?
They are inverter/chargers with built in changeover switch, if you are running off batteries, They are an inverter DC to AC, If you have AC in, eg gen or shore power the are a charger AC to DC, There is also an aux out that if you do have electric start gen, it's parameters can be programmed (or shore power)
They are pretty much the same as the other offerings by Trace Victron etc, A little better in some areas of performance, But OB's ruggidity, Customer service, (5 year guarantee, Have a fault, the replacement board is in the post next day) & field serviceability sells them for me,
Site, click products on top left Outback Power Inc. - Home / Inverter chargers / bottom of page is mobile/ marine, / Model you want / Bottom right of page is list of specs & manuals, Mobil / marine drop neutral, If you do not need that "Normal" VFX's will be fine (maybe cheaper :-))

Tim