Phase Converter/ Motor Question

[BBoi00]

I'm building a phase converter for a siren I have and I just have a simple (I think) question. The motor I have is 240v 37 amp. I have a 240v 30 amp generator. If I run a motor at its rated voltage but not is rated amperage how will it affect the motor. My concern is motor damage. Thanks for any help!

[JasonC]

The siren motor or phase converter motor? Regardless, neither siren you have in your signature is going to work with that generator and especially with a phase converter in the mix.

[Synther]

If you draw more than 30 amps from that generator, it will either cook the motor (in the generator), slow the engine (which lowers output voltage), or it will stall the engine. It could also blow a fuse, if its even got one.

[BBoi00]

I was referring to the phase converter motor. The generator has running 6700 watts and startup 8600 watts. The generator also has a breaker on every outlet, thus I believe that should prevent any damage to the generator. The motor for my phase converter is a 15 hp, 220v at 40 amps full load (I will be starting the motor with a pony motor). I should also note that I do not intend to fully power my siren but only to growl it. The STL-10 motor is three phase and supposedly 15hp, however I feel like it is more than likely a 10 or 7.5hp motor due to the fact that the phase converter motor makes the STL-10 look small

[Stormsetter4]

You're not gonna be able to run that kind of a load on a generator that small. A phase converter of that size needs something along the lines of a 100 amp service running to it. You're also going to need a bigger phase converter motor to run that STL-10, at least a 20 or 25 horse motor, a 15 isn't going to cut it. Always double the hp of the motor you're trying to run to size your converter, and on sirens it's always a good idea to go a little bigger due to the high intertia starting load.

[Unit of Civil Defense]

Tying a phase converter in with electrical power, whether it be generated power or commercial power , is something that that I would advise against. There are more components needed to properly and SAFELY convert the electric phase.
I think Federal Signal's mobile siren (a demo unit??? seen one this past week in the back of a 1 ton pick up) has its own power source (generator, perhaps a 20kw unit??)....at any rate, find out what the manufacturers are using for power generation on their portable units.

[Wdr]

The motor may be bigger because it is 1800 rpm vs 3600 rpm for the siren. That does not mean it will do better as a phase converter. As others have said, 2x hp minimum, especially with no balancing capacitors to bring voltage on generated leg up. Rule of thumb for generators and motors is I believe 3x motor wattage. Also siren motors are built smaller since they run briefly, they are less efficient and harder to start than others. I was barely able to start a 7.5hp siren on a 20hp motor for perspective.

[OHIO Desperado]

You would be better off to run that with a VFD instead of a rotary phase converter. You would have better control of the inrush current and be able to spin the motor up slow. The other thing with a VFD is you can bring the RPM up to 40% or what ever and hold it.

[BBoi00]

I feel that I should note that I went through with running the phase converter and everything went fine. I knew that this generator wouldn't be able to provide the startup amps required, so I instead used the test button on my AR timer in short pulses in order to slowly spin the siren up. I was able to get my siren to the equivalent of a growl. This is to the extent that I'll be testing the siren at my house until I move out and purchase my own house due to the fact that there isn't the available breaker space at my current location. Thanks to all that gave informative replies!