Hi guys i want to set up reversing contactors for the opening/ closing of a sliding door. I have done a mock up of the circuit on my workbench which includes the reversing contactors a stop button an e stop button and the forward reverse buttons. I have wired it all up ( minus the motor) but when i press the first button one contactor pulls in and vibrates slightly while the other one chatters a little and acts like its trying to pull in. When i press the stop button and e stop button the contactors switch off so i believe i have this part of the circuit right at least! Just not sure what i have done wrong regarding the first part. Below is a link to a page where i got the wiring schematic from. Just scroll down the page to the Full Voltage Reversing 3 Phase motors shcematic. Any input would be great. Particularily on the wiring front. Thanks!


http://library.automationdirect.com/how-to-wire-a-motor-starter-issue-5-2005/

 

The selected contactor should latch in if it is wired to that schematic. Check that the contactor coils are 24 volts and that the 24 volt supply does not drop down in voltage when the forward or revese buttons are pressed. You could also check that a contactor will pull in if the coil is connected directly to the 24 volts. That circuit has a major design fault. There is no interlock between the two contactors. if on contactor is closed and the button for the other contactor is pressed both contactors will close shorting out the mains supply.

Les.

 

The selected contactor should latch in if it is wired to that schematic. Check that the contactor coils are 24 volts and that the 24 volt supply does not drop down in voltage when the forward or revese buttons are pressed. You could also check that a contactor will pull in if the coil is connected directly to the 24 volts. That circuit has a major design fault. There is no interlock between the two contactors. if on contactor is closed and the button for the other contactor is pressed both contactors will close shorting out the mains supply.

Les.

Hi Les thanks for the prompt reply just to add the contactors I have are a dual telemec unit with interlock in them already and the coil on them is 230v I just think I have gone wrong somewhere with the wiring, silly question but does it matter what side of the NO buttons I go in to as in the top or bottom or does it matter?

 

Do you mean the forward and reverse button as they are NO (Normaly open contacts). The stop button has normally closed contacts. (NC) If so it does not matter. It would be much better to show the schematic that you are using rather than a different one.

Les.

 

Yes that's what I mean I havent changed any of the wiring yet from the schematic I attached won't be able to get back to it until tomorrow but I followed it as per diagram attached

 

It is best to use a proper reversing contact pair than individual contactors, these have physical interlocks and contacts for electrical interlock also, this physically and electrically prevents one fighting the other.
Also if using AC contactor coils, you can burn one out if it the armature is prevented from closing when under power.
Telemecanique wiring diagrams
See fig6 p8 for one, one discrepancy in these prints is the use of the O/L on the RH side of the contactor coil, now it would be on the left of it.
Max.

 

https://ie.rs-online.com/mobile/p/contactors/1221026/

These are the contactors I am using

 

Those have mechanical interlocks and have electrical interlock capability, are you using it?
If that is 240vac coil then as mentioned, you can jeopardize the coils if not interlocked electrically.
Max.

 

Yes I am well I think so Im just not sure f the wiring on it really

 

Can you show a schematic or drawing?
Are the aux contacts N/C?
Did the PDF ref. not help at all?
Max.