Combine 3 x single phase/220v = 3-phase power?

[sailorman]

I am OP. I have a 3-phase power supply. Some marinas, including mine, offer that kind of power supply on the pontoon. Others don't, which is why I'm looking to add the ability to take multiple single-phase power supplies as described.

the 3 phase supply i would assume is split onboard into 3 separate 240v single phase supplies

 

[PaulRainbow]

Still think OP has three single phase inputs due to high power usage.

Can you buy 240 AC three phase domestic equipment ? how many marinas have 240 AC 3 phase on the pontoon ?

Brian

I agree with Brian, i think the boat has a 3 phase connection, but then it has three 240v AC systems once onboard.

There may well some odd equipment that's truly 3 phase, but i'll bet most is 240v.

The only viable answer that i can see is to supply the boat with 2 or 3 separate 240v inputs when 3 phase is not available. I would imagine that the boat systems will already be on 3 separate and reasonably load balance circuits. It would be relatively simple and inexpensive to connect 3 240v inputs to the boat, at some point after the 3 phase is "split". There'll need to be some changeover switches to keep it all safe and make sure that the 240v supplies don't connect back anything 3 phase, not least the exposed pins of the input connections.

This way, if 3 phase is not available at least some services can be run from 1/2/3 separate inputs. First one would run lights etc, second one would run whatever was the next priority and the final one would be the heavier loads like washing machine etc. Anything true 3 phase would not work, but the generator could be used for those.

Trying to invent a device that blends 3 single 240v inputs into 3 phase would be a shot in the foot, if there were not 3 separate inputs, there would be no power at all.

 

[Graham_Wright]

The only device he states is actually three phase is a pump.

 

[penberth3]

.......You can't just parallel up three 16amp sockets and assume that they are all on the same phase.....

Whatever you do with it on board, single or three phase, this flags up danger of using more than one shoreside socket.

 

[PaulRainbow]

I am OP. I have a 3-phase power supply. Some marinas, including mine, offer that kind of power supply on the pontoon. Others don't, which is why I'm looking to add the ability to take multiple single-phase power supplies as described.

So, all of the equipment on your boat is 3 phase ? You have a 415v washing machine, kettle, toaster, light bulbs, TV, laptop charger etc etc ?

I think not, so does Brian (Halcyon). We think you have a three phase connection into the boat, which consists of three 240v phases. Once onboard this connection can be used to run 3 phase equipment (obviously) but it can (and almost certainly does) run normal 240v equipment. Normal practice here would be to take a 240v circuit from 1. 2 or 3 phases, as required. Typically something along the lines of all low current type devices from one phase (lights, sockets, maybe water heater), then the washing machine and dishwasher from the 2nd phase and perhaps air-con from the 3rd phase. With such and installation you could supply the 1st phase from a single 16a input, the 2nd phase from a single 16a input and the 3rd phase from yet another single 16a input. If only 1 input was available, you at least have lights and basic services.

 

[PaulRainbow]

Whatever you do with it on board, single or three phase, this flags up danger of using more than one shoreside socket.

You can use more than one shoreside socket, some big mobos (and a few big yachts) do it all of the time. You just have to keep the circuits totally separate, on the assumption that they could be on different phases.

 

[Graham_Wright]

So, all of the equipment on your boat is 3 phase ? You have a 415v washing machine, kettle, toaster, light bulbs, TV, laptop charger etc etc ?

I think not, so does Brian (Halcyon). We think you have a three phase connection into the boat, which consists of three 240v phases. Once onboard this connection can be used to run 3 phase equipment (obviously) but it can (and almost certainly does) run normal 240v equipment. Normal practice here would be to take a 240v circuit from 1. 2 or 3 phases, as required. Typically something along the lines of all low current type devices from one phase (lights, sockets, maybe water heater), then the washing machine and dishwasher from the 2nd phase and perhaps air-con from the 3rd phase. With such and installation you could supply the 1st phase from a single 16a input, the 2nd phase from a single 16a input and the 3rd phase from yet another single 16a input. If only 1 input was available, you at least have lights and basic services.

Read #23

 

[sailorman]

Read #23

a pix of the label on the pump would help

 

[DownWest]

Our last house was on 3 phase, but the only bit that needed it was the (bore hole) pump, so a bit like the OP. So, if he wants wants to be able use single or 3 phase, then a chunky rotory switch that bunches the three circuits together for single phase and limit his usage. Or connects them to seperate independant inputs and he gets lots of long shore power cables , or runs them on three phase, as before. The pump either is not used on single phase, or has an dedicated inverter. These are commonly used on 3P motors with lathes or other ex factory kit that gets used in domestic work shops.
A single switch could do all that, Otherwise interlocks to avoid cross connection.

 

[Kinsale373]

Its unlikely that 230V systems will have breakers /fuses that will allow the current that you require to convert to 3 phase. A lot of diesel generating sets above 30KVA supply 3 phase power . Would this be a solution. Change to a diesel generator when you require it.

Kinsale 373

 

[Buck Turgidson]

Or replace the one 3phase pump with equivalent single phase item and get rid of the obscure requirement.

 

[PaulRainbow]

Read #23

Yes, he said the pump is 3 phase, he also keeps saying everything is 3 phase. So who knows what he has.

 

[rolf.nielsen]

So, all of the equipment on your boat is 3 phase ? You have a 415v washing machine, kettle, toaster, light bulbs, TV, laptop charger etc etc ?

I think not, so does Brian (Halcyon). We think you have a three phase connection into the boat, which consists of three 240v phases. Once onboard this connection can be used to run 3 phase equipment (obviously) but it can (and almost certainly does) run normal 240v equipment. Normal practice here would be to take a 240v circuit from 1. 2 or 3 phases, as required. Typically something along the lines of all low current type devices from one phase (lights, sockets, maybe water heater), then the washing machine and dishwasher from the 2nd phase and perhaps air-con from the 3rd phase. With such and installation you could supply the 1st phase from a single 16a input, the 2nd phase from a single 16a input and the 3rd phase from yet another single 16a input. If only 1 input was available, you at least have lights and basic services.

Spot on. Sorry if I didn't explain it well enough earlier. I have one pump that needs 3-phase power, all the rest of the systems onboard are 220v, run off single phases that are split off from the main 3-phase supply.

So I understand the suggestion is to feed each of the 3 on-board single-phase systems with a single-phase 220v supply from shore. I have to check that the galvanic separator is placed correctly in this system, but otherwise it's a simple and good solution. I'll then only be left with my 3-phase pump. Let's assume it runs at 4000w so that a single phase of 16a power can't pull it. Let's also assume that it needs to be that powerful and that I can't change it to a smaller and/or a single phase pump. What do I do with that pump then?

 

[JumbleDuck]

Yes but are you talking about 3 x 240 VAC single phase input sockets ? or 3 phase 240 VAC system, 3 phase mains is totally different.

He's talking about using three 16A single phase supplies as input to a hefty single-phase to three-phase convertor.

 

[DownWest]

Rolf
What does the pump do? Could you use a single phase smaller pump in port? Connected on parallel to the big one?

 

[PaulRainbow]

Spot on. Sorry if I didn't explain it well enough earlier. I have one pump that needs 3-phase power, all the rest of the systems onboard are 220v, run off single phases that are split off from the main 3-phase supply.

So I understand the suggestion is to feed each of the 3 on-board single-phase systems with a single-phase 220v supply from shore. I have to check that the galvanic separator is placed correctly in this system, but otherwise it's a simple and good solution. I'll then only be left with my 3-phase pump. Let's assume it runs at 4000w so that a single phase of 16a power can't pull it. Let's also assume that it needs to be that powerful and that I can't change it to a smaller and/or a single phase pump. What do I do with that pump then?

A 4kw 3 phase pump doesn't sound likely, what does the pump do ?

 

[vas]

unless it's a hydraulics pump for thrusters/stabilisers/watermaker???
v.confusing!

 

[rolf.nielsen]

The pump is for grey water discharge. Just checked it again and it's actually 3kw, which suggests that a single phase 220v/16a could pull it, if I can only convert it to 3-phase power?

EDIT: I could add this phase converter on a single 220v/16a phase to run it? Simlug Frequency Converter, 220V 3KW Single-phase Inverter Output 3-Phase Frequency Converter: Amazon.co.uk: Business, Industry & Science

 

[Bilgediver]

I am OP. I have a 3-phase power supply. Some marinas, including mine, offer that kind of power supply on the pontoon. Others don't, which is why I'm looking to add the ability to take multiple single-phase power supplies as described.

What Halcyon was suggesting is that much of your equipment such as washing machines etc will actually be single phase which suggests that not much of the equipment used all three phases. Your electrician should be able to confirm this and offer a solution giving you the use of domestic lighting and galley equipment.

 

[rolf.nielsen]

What Halcyon was suggesting is that much of your equipment such as washing machines etc will actually be single phase which suggests that not much of the equipment used all three phases. Your electrician should be able to confirm this and offer a solution giving you the use of domestic lighting and galley equipment.

Thanks, yeah as I have clarified in later posts, I only have one pump that runs on 3 phases, the rest of my system is single phase. So I can connect 3 single phase shorepower cables directly to the boat's three single phases (split out from the 3-phase shore supply). That means I just have to find a solution for my 3-phase pump as discussed above.