Motor with braking facility

[Irmschur]

Hi all, just woundering if anybody has worked on a Hanning 3 phase motor with conbined electric brake? Went to a job today to look at an industrial spin dryer that needed some sort of brake fitting to the motor, by the looks of things and from what I have been told from owner, there is a brake conbined in the motor. From what I can see there is only 2 wires that are loose from anything and they are about 0.5mm thk with no voltage running through them, but there is continuity between them. Is there some sort of module that pairs up to this type of motor that contols the brake?

 

[Graeme Harrold]

Was the dryer working? I only ak as in most cases brakes on any kind of rotating machinery (electric or hydraullic) are mechanically applied and electrically (hydraulically) released.

 

[Darkwood]

As Graeme points out above either the brake isnt attatched or its jammed open as for the 2 wires they could just be a thermal cutout connection embedded in the motor.
You say its a 3phase motor what wires have you got connected to the motor?

 

[THE DUKE]

Hi Don't know the motor you have but it sounds like a standard brake motor the brake will be dc, controlled from a rectyfier that is normally in the terminal box but could be in the control panel. Typical voltage could be 24v, 110v or 230v if you take off the motor fan cowl the brake unit is normally behide the fan the voltage it might be stamped on the side. Hope this helps


"Assume nothing and never say never"

 

[Steve1412]

You say the motor needs a brake fitting?. Why is this?. Has the existing brake failed or does the owner want one retro fitting?

 

[Graeme Harrold]

You say the motor needs a brake fitting?. Why is this?. Has the existing brake failed or does the owner want one retro fitting?

Im guessing that he has been called in to retro fit a brake only to find the motor has the facility, but is either not connected or not working. Most rotating machinery needs braking of some sort to allow it to stop within prescribed times under emergency stop conditions.

 

[boatnik1]

Worked on one of these in a laundry years ago, DC injection into the winding was the brake. Sounds like your two loose wires might be it. On the one I worked at, the DC was supplied from a transformer and rectifier in the motor control box. Check the box to see if it's there. Also might be in the motor terminal box.(if it's big enough)
You could try flashing a 12v battery across the wires to see if there is any braking effect.

 

[Irmschur]

I got asked to see if the motors brake on the machine could be re-connected to a new control panel that had been made up by somebody else (not original panel). Thing is there is no brake control within this new panel, and by the looks of the motor there is no internal brake within it either, so from what I was lead to believe by owner of the machine, the 2 wires that are left dangling are nothing to do with a brake facility, but could be part of a thermal cutout.
After coming to the conclusion that this machine has no brake fitted to the motor, a 5.5kw brake contactor has been fitted within the control panel, but this still does not slow the machine down quick enough when it is under full load. So after all this I dont no what the next step will be.
Any surgestions???

 

[boatnik1]

If the contactor you have fitted has a DC injection module in it, is there not an adjustable timer to increase the period of injection.

 

[Irmschur]

yes there is a timer and current control within the unit, but both set to 100%

 

[boatnik1]

Presumably this drier is some sort of Hydro extractor and is carrying quite a large load of laundry which causes a centrifuge effect and causes the electrical effect to be over-ridden by the flywheel effect of the drum. If that is the case then a mechanical brake may need to be fitted. You might be best to contact the machine manufacturers for advise as these machines can be dangerous for operators if the braking effect is not to spec. Repairing it to a spec other than the manufacturers might leave you liable in the event of an accident.