Hi dudes
i'm having a problem with the control of 3 3 phase contactors. The machine was running fine all day and then when it was stopped for 1 minute it wouldnt restart. On inspection i found that when the start button is pressed the contactors pull in for about one second and then they pull out again. It is like it is not latching. I have checked the circuit and found that things are where they should be in relation to continuity. So what i did was i took off the start push button switch and put on a rotary stay put switch. When i do this the machine runs and latches no problem and all the safetys (doors and e stops) still work too but i have to turn off the switch in order to stop the machine as the stop push button wont do it (obviously) when i try put the start push button back on the same thing happens it latches for 1 second then stops so i assume i am losing a leg of the latch circuit somewhere but im confused as it all runs on the rotary switch. Also when the stop button is pressed it pulls in a safety contactor in order for the rest of the circuit to run and when the machine is turned to position 3 and the stop button is pressed it works as a jog function for an external conveyor and this too is all working so am i on the right track assuming its the latch when its turned to position 1 and 2 which is normal operation
thanks guys
PS no drawings or plc access to this machine either
i'm having a problem with the control of 3 3 phase contactors. The machine was running fine all day and then when it was stopped for 1 minute it wouldnt restart. On inspection i found that when the start button is pressed the contactors pull in for about one second and then they pull out again. It is like it is not latching. I have checked the circuit and found that things are where they should be in relation to continuity. So what i did was i took off the start push button switch and put on a rotary stay put switch. When i do this the machine runs and latches no problem and all the safetys (doors and e stops) still work too but i have to turn off the switch in order to stop the machine as the stop push button wont do it (obviously) when i try put the start push button back on the same thing happens it latches for 1 second then stops so i assume i am losing a leg of the latch circuit somewhere but im confused as it all runs on the rotary switch. Also when the stop button is pressed it pulls in a safety contactor in order for the rest of the circuit to run and when the machine is turned to position 3 and the stop button is pressed it works as a jog function for an external conveyor and this too is all working so am i on the right track assuming its the latch when its turned to position 1 and 2 which is normal operation
thanks guys
PS no drawings or plc access to this machine either