I do mining equipment, recently I used ABB frequency converter to put into our equipment, but the problem of interference really gives me a headache! We have two pieces of equipment of SIEMENS S7-200 PLC, and is used in point to point protocol communication with each other, when the converter work PLC communication interference! There are monitoring equipment, converter work, there are a large number of snowflakes on the screen, simply do not see! Not even an internal phone! I've done well in grounding, but I still can't do it! Is there any master who can teach me a trick?
Solutions to interference caused by electromagnetic radiation:1. access reactor2., the correct grounding - grounding wire as close as possible to the frequency converter, the principle of power lines, frequency converter for the ground wire must be usedThe ground wire is separated from the other equipment, and the earthing of all the equipment must be avoided before grounding.The earthing terminal of the frequency converter can not be connected with the zero line.3. access filter.4. reduce carrier frequency.
Reasonable wiring: 1. principle - control line as far as possible from the input and output lines.2. non parallel principle - the control line should be crossed as far as possible in the space and the input and output lines, preferably the verticalStraight crossing, not parallel.3. phase principle - two control lines are adjacent to each other.
You can try using the following methods:Solution of interference caused by circuit coupling:The PLC and monitoring equipment are powered by isolated transformers.
Solution of interference caused by inductive coupling:The control circuit using shielding line, when connected to the control line and the inverter, the shielding layer can not only be grounded, one end connected to the transducer signal terminal can pay attention to public, regardless of whether the public or end shield grounding, only in the end, and can not be connected at both ends.
