3 phase motor with neutral

[stressed]

Is it allowable to take a 230v supply out of a 3 phase motor connection box, taken off one phase and a neutral?

 

[malcolmsanford]

Is there a neutral at the switch isolator or are you saying there is a neutral at the motor termination box?

 

[Jonesy83]

3 phase motors usually have a nuetral supplied if it has a brake usually a 230 v dc is there a rectifier inside the motor connections and has it got a brake fitted

 

[Marvo]

Sounds to me like you want to use one of the phases of the motor supply + neutral to run another circuit for something else.....if so I would say no, it's a bad idea. Motors are usually supplied via a protective device. Using the motor supply for an additional circuit will cause havoc.

 

[davelerave]

won't be suitable alright-as the motor is prob closely protected by overload

voltage at the motor terminals could drop a fair bit at startup as well-down to 80-85% and might affect whatever you're branching off for

 

[telectrix]

overload, unbalanced phases, buggered motor, should be fun. so it's a no from me as well.

 

[Guest123]

Is it allowable to take a 230v supply out of a 3 phase motor connection box, taken off one phase and a neutral?

For what???

 

[pmac10]

it has to be a brake. use one phase and the star point for neutral

 

[silva.foxx]

similar to pmac above... I've seen this method used on a conveyor system where a 240vac solenoid is connected to a phase and star point, for a lube system.

 

[malcolmsanford]

To be honest lads Lenny is right ..........what? it could be to power a kettle, we are all assuming a brake or like. But think the OP as given up on this

 

[Hawk81]

it has to be a brake. use one phase and the star point for neutral

It does not have to be a brake. I have seen motors with 230v heaters built into the motor to keep it warm when not in use.

 

[Deleted member 26818]

It does not have to be a brake. I have seen motors with 230v heaters built into the motor to keep it warm when not in use.

Such, would be taken from the supply before the starter.

 

[johnboy6083]

i wired some motors today, and they had seperate supply for 110v heater.

 

[Engineer54]

In what circumstances would a heater be required within a motor??

I must admit that i haven't to my recollection come across such a circumstance. The only exception has been in compressor units where a heater is employed to keep the refrigerant in a gaseous state....

 

[Steve1412]

We have several motors with internal heaters varying in age from 40 years down.........some are in pretty damp nasty places too!!! still over 200Meg on the IR test though!!!!!!