Roto Phase motor

This is a bit murky. The way I read your post is:

You have a 230V single phase motor somewhere and you are not sure if it works properly.

You used to have a 3 phase bow thruster

That unit may have been powered by a rotory phase converter

The phase converter is disconnected

A 3 phase motor someplace works when powered up

There may or may not be a motor starter for the 3 phase motor

There may or may not be a "step up motor" in some circuit

You don't want to apply power to the 230V single phase motor but want to know if it works.

Is that accurate? What is a "step up motor?" Is that what you call a rotary phase converter? If T1 and T3 are disconnected from the converter, how does it run the 3ph motor you mentioned? Do you have a separate 3ph supply available that runs the 3ph motor?


Supply the nameplate data off the motor you want to test and I or someone else might be able to provide you with a starting point pretty quickly.

Electrical problems are sometimes difficult to troubleshoot online but it can be done if very clear descriptions of what you have and what it is supposed to do vs what it appears to do or not will increase your odds of getting some help.

Otherwise, hiring an electrician to attend the vessel may be your best solution.

It sounds like you have a 3phase motor that was wired as a phase converter to feed another 3 phase motor that drove the bow thruster. Is that correct?

If that is the case, take the motor being used as a phase converter to a workbench with 3 phase power and see if it works, you can't hurt anything as long as the supply is fused to match the starting current of the motor. If there is a motor shop nearby they can test it for you very quickly and may do it for free or very cheaply hoping they will get to sell you a replacement. It is really quick and easy to bench test a motor.

Since you have the wiring diagram, if the motor works, rewire the system according to your diagram and replace the single phase bow thruster motor with a matching 3 phase motor and you are in business.

Have a look at this site:

http://www.metalwebnews.com/howto/ph-conv/ph-conv.html

These guys have been helping home machinists who lack 3 phase power to get their surplus machines running for years.

Google "build rotary phase converter" and you will get a pile of links with wiring diagrams and explanations of how they work. That may go a long ways to help you sort out your problem.

http://www.metalwebnews.com/howto/phase-converter/phase-converter.html

Good luck, let us know how you do.

Does the motor have nine or twelve leads. I can give you ring-out parameters you can check with a meter if i know the number of leads.

Ted

Or 6 or 3 leads but not common. I am going to be away from my computer.

Look here. http://www.elec-toolbox.com/usefulinfo/mtrconn.htm

The "2" is missing from the Delta pictorial. If you make the connection at 1, 2 and 3 you can ring the motor out. You need a decent meter as the resistance will be from a fraction of an ohm, say .33 ohms, to a few ohms, say 2.3. If they are not close when measuring equal length leads or they are open or they go to the frame (ground) anywhere, then the motor is bad. If they ring out ok, the motor could still be bad when under normal voltage or a load but they usually smell...course you can't smell much on a thruster unless on the hard.

Good luck.

Ted

Ah, I see the problem now ... that red wire connected to the blue thingy in the top picture is loose.

Boy! Are we supposed to comment on this? And is all of this for the thruster?

A few things bother me but these are just guesses. For one the the three phase contactor with only two wires attached...presumably the power to the single phase side has solid wires where thermal overloads typically are found. I may be wrong, keep that in mind, but if that is the case that is a good way to burn up the single phase motor. It appears there is a reversing contactor in the upper left. Does that have an electrical or mechanical interlock. If electrical, check it out so you are not trying to run the single phase side both ways at the same time. Lastly, there are a lot of contacts to go bad. All of those need to be checked and cleaned.

Remember, all guesses.

Hope this is some help!

Ted

"Surely there's a simpler system!"

If all you are trying to do is run the bow thruster, then yes, that is an understatement. Look at the links I provided and just add a reversing relay. This is not rocket science.

It is not rocket science but the fact that there apparently is a 3 phase thruster with only single phase power available complicates it a bit.

Ted

We the readers still don't know if the thruster motor is single phase or three phase. You asked how to test a 1ph motor then started to describe a 3ph system.

Reading between the lines of your posts, it seems as if the bow thruster is now powered by a single phase motor because of some previous failure in the system. Did the 3ph thruster motor fail and was replaced with a 1ph or did the kluge of a control panel die and the converter is being bypassed altogether to drive a 1ph motor and the convertor motor is out of circuit?

Judging by the photos, there appears to be a another control feature and some sort of dispaly which may or may not be functional at this time. Like I wrote earlier, it is very difficult to troubleshoot electrical failures via a BBS and more so when most of the relevant information is missing. If you have the circuit diagram available most competent electricians should be able to troubleshoot the system. If you don't then it probably isn't worth throwing more money at it.

What is not rocket science is the fact that if you want to use a 3ph motor to drive your thruster but only have 1ph onboard you can make 3ph via a rotory converter and use a simple reversing contactor to control the thruster direction. The circuit is simple and cheap. This can be performed with a minimum number of components and you can dump the overly complicated and probably hideously priced collection of stuff some fool got talked into before you bought the mess.

My thoughts exactly.

The display device is I believe a 3 phase inverter and /or a freq. drive. Perhaps used as both a soft start and to get the three phase power.

It looks/sounds to me like systems have been bypassed and/or replaced as other systems failed. My guess is the inverter replaced the rotary converter or vice versa. Because I don't see why you would need both.

Of course there only seems to be two wires hooked to the motor so perhaps it all failed at some point and they were running the motor at reduced speed in single phase.

I vote rip it out and start over and KISS it.

There are 2 ways I know of to start and run a rotary phase generator.

1: use a pony motor,like 1/3 or 1/2 hp ,energize it, and by belt or direct drive bring the larger 3 phase motor up to speed before energizing it. Failure to due so will cause the 3 phase motor not turn ,overheat and then fail.

I would bet this is what the smaller motor is for & all the complex wiring. To first energize the pony motor,when phase generator is up to speed ,energize it and stop power to pony motor. Early phase generators used this method.


2: By the use of a capacitor bank create enough phase offset to get the rotary 3 phase generator started without a pony motor.


One another note: A rotary phase motor will generate L1 & L2 @ supplied single phase voltage but L3 will be a lower voltage. 3 phase power ,L3 is a higher voltage (leg) than L1 & L2. The low leg from a rotary phase generator can also be corrected by the use of correctly sized capacitors.

I don't see any capacitors in the pictures, so method 1 is how I would say your system works and they just accepted the low voltage on L3.