ASEA shore power /Seamless transfer

Hi,

I have no experience with this unit so can't comment.

You do not need any fancy hi tech unit to enable a change between gensets without blacking out the boat.

If your switchboard is setup to allow the gensets to parallel automatically then you already have everything you need to make this happen.

You want to change to a different genset? You bring another one online when it's settled down and on load you take the other one offline.

Hi,

Is it about the same issue, mentioned in the topic "electronics protection" ?
If yes, then please attend a post from that topic.

Regarding all these "very modern, maintanance free, all-in-one, seamless, PLC controlled, easy to install, etc" fancy systems - it's not necessary when Your switch-board is equipped with manual or auto synchronizer.

Is Your switchboard equipped with synchronizer ?

Regarding change over from genset to shore power:
Only look that phases are corresponding. Normally, switchboards are equipped with a special device (a small 3 phase AC motor), which detects that.


rgds,
Andrei

Hi,

Comship are you saying that you have no means of external speed control of the gensets?

If this is the case then I doubt you will find anything on the market that can allow you to parallel or switch between them seamlessly.

To parallel and to switch seamlessly the gensets have to be able to be matched at a 0 Volt difference, the correct method for this is to have the incoming genset running slightly faster than the on onload one as it will suffer a speed drop when it comes onload itself.

If you are still at the stage of building the Boards and such then it is time for a Change Order to get this situation resolved. Otherwise you are going to have a lot of headaches further down the track for sure.

I am actually quite surprised that your Naval Architects/Designers have let you agree a contract based upon a specification that is missing such an important thing. It makes me wonder what other important things have been overlooked.

Did you have any professional help in preparing the specification at all?

Also. Please don't blow off TSI AV's advice, he is a very knowledgeable technical contributor on these boards. What he says is correct in that you have already started a thread along these lines and you should post in it that way someone searching the forums with a similar question can see the whole lot laid out in one easy to follow series of posts.

Hi,

COMSHIP,

By the way, "we" are trying to help You...

ok.

1. If Your contract really includes engines whithout fine remote speed setting adjustment (governor's servo drive), do smth about that contract!
Actually, I doubt ... Must be at a least a bolt/nut, which pressures against the speed setting main spring inside the governor. (otherwise it's not a governor anymore at all)

2. If You have information what type of governor to be installed, please post. If possible - scan some drwgs.
I hope, that it's possible to install a servo-drive on it somehow.

3. But, if that "magic" governor is really so *@#$@$ !, You can contact a WOODWARD and ask for alternative.
They manufacture mechanical / electronic governors for all brands / types of engines.

4. Please bear in mind, If Your yacht will go under one of Classification Society rules, You may encounter problems as well.

5. Keep insisting, that Power Management system has to be well designed/installed. If they can not develop one, contact INTERSCHALT, EEKELS, etc.

6. I would like to meet a guy who designed such a "piece of the art",

Please, keep us posted about whole matter.

Will be glad as to assist.

Rgds,

Andrei

Two questions for TSI and K1W1:
1. Is it really all that uncommon for yachts to not have a seamless transfer set up? The yacht that I am on and the one before did not. This one does transfer seamlessly form shorepower to either Gen or back but not between them. It is accomplished through a frequency drive integral with the Atlas shorepower system. It is never really an issue because the our usage is such that we don't need to change genny's under way ever (no catastrophic failures to date) and each 65kw gen is adequate to max house load.
2. What's wrong with what I suggested in and earlier post about simply allowing the shore power system to handle seamless transfer between gensets via frequency drive, since the system will be there anyway, rather than an additional system to provide paralleling and transfer through speed control? I know that is traditionally how it is done but is it better?

Hi,

yotphix, I think you might be missing the point here.

What do you do when the running generator needs to be serviced? Black the ship out while you change? Go back to the dock and plug in to do it?

What is the greatest advantage of an Atlas or other modern Shorepower system? I understand it is the ability to plug into a wide range of shore power and get out a reasonably stable supply to your boat.

It is not a necessity to have one of these by any means. If the boat is not going to go far from it's home base them it's a good cost saving to not have one plus there is the weight and space issues to contend with as well. If as you say your usage is such that you never need to change it sounds as though you don't go anywhere far from home then your owner could have saved himself some money and not fitted one too.

Nope. Not missing the point at all thanks. Actually the unit on this boat is very useful for shore power in the med and on the dockship and occasionally in Mexico. I agree completely that it would be preferable to be able to change gensets seamlessly, which I cannot on this boat and never suggested otherwise if you read the post. The question was whether there is some reason that it is better to regulate genspeed to match phases rather than use electronics. It is ok if you don't know the answer K1W1. It is just a question.
As the OP already stated, he is planning a shore power system as it stands. I am not saying that he doesn't need what you have recommended or disagreeing with you in any way. It is just a question.

Hi,

The answer about seamless transfer is yes, in my own experience it is uncommon and is something that is usually only encountered on older vessels, there has always a means to manually parallel the gensets but I have also used a system where the generator load could be shared around by sections of the switchboard being served by a series of rotary switches so each generator could be assigned to a section or two of the board when the bow thruster was in use or one could do the lot when it wasn't

Before you get ahead of yourself -The automated regulation of generator speed for paralleling does require some electronics when done via the PMS, it has to match 0 volts as I wrote previously.

I believe the OP as you call the first poster was asking if anyone had any experience with the system he asks about as he was "thinking to install one".

Hi,

These units adjust the speed of the generstors to match the voltage on the BUS ( The main rails inside the switchboard)

You can read about the Woodward ones here.

http://woodward.com/pdf/ic/37292.pdf

One is required for each genset as it can only control a single Circuit Breaker

Hi,

Guys, I'm quite busy at this moment (2 commercial ships are in dry-dock within last 3 weeks), but today/tomorrow I will make and post some pictures of synchronizer, phase detector, some electrical drwgs.

rgds,

Andrei

Hi again,

COMSHIP, have a look at pictures attached.

Picture 1.
This is a synchronizer.
"M" is a that moment, when necessary to switch "ON" the main breaker of the genereator what has to work in parallel.

Picture 2.
Frequency meter. I - generator, which is "ON" already, II - which is supposed to be switched into parallel.
"S" is a switch for chosen generator for parallel work.

Picture 3.
Phase direction detector.
Before You change for shore power, phase direction must be correct.
"D" is a disk (a small 3 phase AC motor is inside) which will turn in either direction. "correct / not correct".

These pictures are taken from a ship, which is 25 years old.
So, the system is basic. It works for 25 years. No electronics. No blackouts.

rgds,

Andrei

I would be interested in finidng out how you like the ASEA system once you have the vessel up and running as we have one ordered for our vessel.