1, the frequency converter to the motor cable should be shielded cable? 2, whether there are specifications?
Or, ask another question: "under what circumstances can the frequency converter go to the cable of the frequency conversion motor without using shielded cable?" Is there a "no need to use shielded cable" basis?
When we design the frequency converter to drag the motor load (mostly fan and water pump general machine), we should use shielded cable. We refer to the GB/T21209-2007 "inverter power supply design and performance of cage induction motors in section 9.1.4" guide "motor power cable" 9.1.4.1 "recommended configuration" in the "provisions of more than 30kW motor wiring should adopt the single core power cable or a plurality of grounding wire arranged symmetrical cable. Small power and suitable for wiring, priority is to use multi-core shielded cable." As the PE line symmetrical configuration of the 3+3 inverter dedicated cable, construction is always raised, not wiring, we later too lazy to explain, usually directly with the 3+1 type multi-core shielded cable. From the running situation, the effect is also good.
Do not use shielded cables have several conditions: the first is from the inverter to motor wear long steel pipe laying cable. Second is the frequency converter to the motor cable line routing (cable bridge, cable ditch), there is no analog signal cable or other weak signal cable. Otherwise, from the debug runtime, if the inverter cable cable line motor and analog signal very close, even if the analog signal shielded cable control cable when the motor running is still very obvious interference of analog signals, especially large power motor.
1, there are no special specifications, but each oneThe manual must have all the precautions required for good shielding.When the output of high frequency voltage pulse, the higher the frequency, the greater the external radiation interference. UseThe line is mostly blockedExternal interference.2, if there is no other equipment around (usually 5 meters as the boundary), then the shielded line can not be used, because there is no external interference.
