3 phase starter/contactors

[Blue]

Sounds like your problem is an overload problem bot to replace the starter wouldn't be a big job you could even leave the original front plate on just disconnect the wiring to the motor and take to the new starter as in the Alan West starter

 

[boatnik1]

Sounds like your problem is an overload problem bot to replace the starter wouldn't be a big job you could even leave the original front plate on just disconnect the wiring to the motor and take to the new starter as in the Alan West starter

Problem with most of these old starters was that there was no overloads fitted so they just stayed connected until you switched them off,or a fuse or fuses blew, usually when the smoke from the motor was blinding you.

The motor and starter would obviously still need to be checked for shorts/broken windings/connections etc. before any new kit was fitted.

 

[gorilla]

Just thought I would update this, problem has been diagnosed by our spark, and it was nothing serious just that the starter's contactors are needing replaced. The actual motor is in good working order for its age, just now it is working as the contactors have been cleaned up and things set so that it will work but that will only last until our spark returns from his job offshore where he will probably be nicking someone's contactors and leaving them wondering what is wrong.

 

[eccoseman]

Sorry to come in so late.
Don't think you have an electrical fault.
The contactor seems like the Allen West type with hydraulic damper dashpots. Little cups under cutout coils. Unscrew cups and check piston and plunger. Should be clean and have approx 1/4" light oil in cup.
If cup is empty or oil is low, over current lifts piston and the plunger unlatches 'hold' mechanics. Contactor won't hold.
3 phase machines have three cups. Depth of oil (or travel of piston) sets the over current trigger point. Adjusting the height of cup sets the point. Don't overfill. Fill to height of 'sleeve' with piston in place.
Regards.

 

[Engineer54]

Problem with most of these old starters was that there was no overloads fitted so they just stayed connected until you switched them off,or a fuse or fuses blew, usually when the smoke from the motor was blinding you.

The motor and starter would obviously still need to be checked for shorts/broken windings/connections etc. before any new kit was fitted.

This may be an old post, but i have to say, i've been around in this industry for a long time now, and i've never once seen a motor starter without some form of O/L protection, be they Oil Dash pot or the Bi Metal variety... (Well tell a lie, Electrical Em fire pumps, that have designed to run to destruction won't have any such protection ) What would be the point of a motor starter without a means of an adjustable O/L ?? You may as well run the motor directly off the old fuses. But then, the O/L's would have protected the motor to some degree, (depending on the close setting of the O/L's) against single phasing, when one fuse had blown...

 

[Knobhead]

Eccoseman, the fault was diagnosed 22 months ago. Why have you resurrected it?

 

[Specialist]

Eccoseman, the fault was diagnosed 22 months ago. Why have you resurrected it?

Fair point mate.