Electric Overhead Crane

Perhaps the thermal overload breaker is kicking out.

Possibly due to tight (unlubed, or worn out) bearings causing excess current drain?

Difficult to tell when there is no information as to which type of/brand machine it is.

More info?

Stu.

Is your crane fed by cable or trolleys? It may lose contact somewhere on trolleys; check your brushes for making sparks while the crane is moving. Is your crane fed through the "travelling wheels" like subway train? Check the brushes on them; maybe you've got to change them? Check also for losing contacts on operation circuits; sometimes they may "respond" on any vibration. If after the crane stops, it cannot move, then it is easy to trace the problem--just find where the phase is lost, but when it can move again, then probably, the phase (or maybe even neutral) is lost for just a moment, and it happens on operating circuit. After the crane stops, you have to "restart" your main controller or restart your system so that your crane could move again, don't you? If so, then your operating circuit opens for just a moment; it can happen when the phase is lost for a moment on brushes; the circuit opens somewhere within the operating circuit: losing contacts; bad auxiliary contacts on your starters (usually happens while crane is moving in one particular direction). Are there malfunctions on other crane operations like lifting? If you still have problems, learn about your crane "behavior" and provide us with more information. Good luck!

An overhead crane is commonly called bridge crane, these types of cranes are used in most of the industry which have heavy loads and continuous shifting process is there. These types of cranes only run on the given paths which were fixed with the ceiling of the building. Take an example like in industry like transformer maker not that transformer that optimise prime but the electronic equipment which convert alternative current to direct current. These types of crane are used for lifting the transformer from one place to other and then they are used for lifting it lastly on the transport. Custom Electrical panel makes even customized cranes as per clients demand and use.

you're probably tripping the thermal overload on the bridge control circuit. check the actual current while operating. higher than nameplate currents indicate mechanical drag or low voltage.

of course, i could fix it for you but then, you're a long way from my backyard.

more information needed for anyone to isolate your problem. send photo, voltage & amperage readings, etc...

simple is as simple does...

I had a(2) 10 T and a 5T

each had (2) speeds but 5T had was traveling pretty fast in 2nd gear??? being empty loads.

any way as it crossed the electrified bar splices, the spring loaded connectors I beleive would jump and I would have to reset the PLC. so what I did was on the plc I slowed down the speed (2nd gear ?) (also increase ramp up time) so the transition on the bars would be smoother. But since I did that, the problems reduced that it only happed once since then.

(btw the plc error code describe it as an over voltage????) It only occured when it stopped on the splice. and tripped when I restarted?)

I t is usually a good idea to have two sets of brushes in parallel.If one hits a bad spot, the one behind carries the current and the one in front passes by the bad spot or bump in the track.By the time the rear brush contacts the bad spot, the front brush is on good contacts. Newer machines are required to have dual brush systems.Adding a second set of brushes behind the first set is usually no problem.

Try it.If you already have dual brushes,then your stop circuit is intermittent.If operated from a pendant, the cable is probably the problem.I recommend changing to a wireless control.Rubber-cord pendants always give problems,even with the best strain reliefs installed.

IF you must use a rubber cord,I recommend using 4 wire hydraulic hose to enclose the cord wiring to the pendant, and make sure the hose is supporting the load from the pendant weight.Use the "Chinese Finger" type braided strain releif on it at both ends.Not foolproof, but lasts a lot longer than rubber cord alone.

Good luck

the ones I had was in line with a sort of saddle/toggle config.....still was doing it.

It came with the building, and I beleive it was poorly designed.

I had the (2) 10 T cranes on the same rail, for flipping equipment. the spool drums were perpendicular to the rail and was working it made it difficult.

Have you tried something called "Maintenance"?

You state you have "rectified the rail on which it travels"

Do you mean the rail(s) that the wheels of the crane run on or there is a power supply rail that is open so collector pick-up arms are in contact with this rail..... similar to the collector arm used on some electric train?

I suggest you try cleaning the rails first, check the collector arms/collector shoes second and get someone who knows how to maintain the crane.

The lack of play in the traveling wheels... can you give more information on that comment?

One more thing i have to update- some times cranes travels cross i.e one end travels more faster then the other