Tripping of conveyor,vibro feeder motors without reason

Hook up a current/voltage monitor with a camera system to coordinate visual inspection with IR graphing. You'll find a condition that causes your overload and be able to properly repair the problem.

^{"Many times we found our material handling conveyor,vibro feeder motors tripped on over load and when we check everything(IR Value) found ok and so we restarted found everything normal.Can anyone clear why such things are happening?How to avoid the same?"}

Sometimes an Over Load is just an Over Load. IR values would only be useful if you could watch it while it happened. After the fact all that will tell you is if the motor is defective. If not, then most likely you had an event with your load that caused it to overload the motor. So either your motor is too small, or you have a mechanical issue to discover and correct.

yes! nice Question..

The over load is not only the problem of motor over loading. It may be the voltage variation in the motor terminal side. But The motor may be tripping due to one of the reason below.

If the votage is not proper in the motor terminal due to the improper contact of moter's contactor. it may cause unequal voltage at the motor terminal side and the motor gets unequal current to the motor in all phases. So that the relay will indicate the overcurrent and finally it will give a trip signal to the motor.

u can check by

at the time of motor loading please check the input voltage (Befor the starter) and the motor terminal voltage. If any mismaches found in all the phases . please replace the motor contacter in the starter unit.

otherwise please service the motor contactor. (the contactor contact is normally over heated at the time of starting, due to this the contact is damaged and it will create the improper contacts)..

Please try it

Ganapathy.S

Ganapathy24@yahoo.co.in

everything posted here is good to check!

so i'll put in my 2 cents worth. be aware of bearings and all other mechanical items under load to your motor. a combination of several things could be causing your trip! touch everything you can and you will soon learn what is going on.

In the doing comes the knowing

Are your breakers in the distribution panel tripping or the thermal shutoff on the motor tripping? I ask this because I have had a few breakers (purchased brand new) that had a tendency to trip under normal use. No overload (5 or 6 amps on a 15 amp circuit) it just tripped. Annoyed, I replaced the breakers and have had no problems since. So....you might just have a bad breaker.

Aside from mechanical issues of the conveyor itself. Belt jams, bearings, bushings etc. You didn't mention what kind of controller you are using. If it is a mechanical starter with thermal overloads (ones that glow when amperage draw is too great) you may have a bad heater coil or one that is rated too low. As stated above your contacts on the starter may be worn or not aligned within the clip correctly. A loose wire on the starter may be a problem also. If you have a jam relay hooked up to one of the lines you may want to check your connections as well. Some of the older dash-pot coils would crack the wires from the coil connection behind where the contact wires were attached. All in all, check all components for correct and tight connections.

Good Preventive Maintenance and thermal imaging can catch problems before they actually occur.

Is your vibro feeder using VSD?

I have the same problem with a machine with VSD, when I measured the motor running current, it's less than the CCC of the conductor and the TOR setting, but after sometime, the cable become warm and not long afterward the TOR tripped.

Later on I realized that the overloading influenced by higher harmonics current that appeared because of the VSD.

So if this is the reason, then you have to reselect the TOR setting.

Regards,

Stanyadji

What is CCC & TOR ?

CCC is the abbreviation of Current Carrying Capacity.

TOR is Thermal Overload Relay.