Hello, we are working on an upgrade to our conveyor system used for educational purposes, and I have some basic panel building questions for those who have more experience than I. To give a quick overview, we have a main cabinet which contains the E-Stop circuits. 3-Phase input at 230/400V comes into this cabinet and is distributed to 5 separate cabinets, each containing a Siemens S7-1500 PLC, and another separate MCC with 5 VFDs.
1) We are using 16 pin industrial grade plugs with "Lapp ölflex classic 110" cable run between cabinets. The cable consists of 12 wires, each with a 2.5mm2 cross section. We are running 3 phases, N, +24V, 0V as well as the dual channel series wired E-Stop pushbutton wires through this cable. There are no analog or other digital signals being transmitted. Does anyone see any issue with running the 3-phase power, +24V and E-Stop pushbutton signals through the same cable?
2) There is no PLC in the main cabinet, but there are a number of miniature circuit breakers which we have tried to coordinate as best as possible in the overall system. In order to signify that a breaker has been tripped, we were thinking of using NC aux switches on each of the breakers, each being connected together at one main set of jumpered terminal blocks, which are then connected to a fault LED on the front of the cabinet. If a breaker trips, the LED goes on. Is this a common/reasonable solution for breaker trip notification?
3) This was covered somewhat in a previous post, but I never got a clear answer. Each PLC has a digital output module with 32 outputs (4 groups of 8). We are only using 2 groups of the 4 (16 outputs) in each cabinet. 1 group is powered by a separate E-Stop circuit and power supply, the other group is powered by a local supply that is not cut upon E-Stop. Each output group is isolated from each other and there is an allowable 75VDC between groups according to the data sheet. Would it still be a good idea to tie the 0V from the safety circuit supply and the local supplies together? Or is there any potential issue with doing this?
4) We are using Siemens 24V S7-1500 8A power supplies, which have short circuit protection built-in. Should we still add a circuit breaker to the output side of the supply? Is this really necessary or good practice? If so, would you connect it directly to the output of the supply, with the other end of the breaker going into terminal blocks?
5) Just out of curiousity, we are using 2 power supplies in parallel for the safety circuit outputs. Each PS is setup with a separate C10 MCB at the input. If one of these trips and it is not immediately corrected, it will keep power to the safety circuit but only provide an output of 8A max, which bothers me. I'm wondering if this is really an issue, and if it would be better to run both of these off of a single breaker, or if it is fine how it is. Upstream of these 2x C10 breakers is a C20 breaker already, if tripped it would shut off power to pretty much all cabinets except the MCC. Any comments here would be appreciated.
1) We are using 16 pin industrial grade plugs with "Lapp ölflex classic 110" cable run between cabinets. The cable consists of 12 wires, each with a 2.5mm2 cross section. We are running 3 phases, N, +24V, 0V as well as the dual channel series wired E-Stop pushbutton wires through this cable. There are no analog or other digital signals being transmitted. Does anyone see any issue with running the 3-phase power, +24V and E-Stop pushbutton signals through the same cable?
2) There is no PLC in the main cabinet, but there are a number of miniature circuit breakers which we have tried to coordinate as best as possible in the overall system. In order to signify that a breaker has been tripped, we were thinking of using NC aux switches on each of the breakers, each being connected together at one main set of jumpered terminal blocks, which are then connected to a fault LED on the front of the cabinet. If a breaker trips, the LED goes on. Is this a common/reasonable solution for breaker trip notification?
3) This was covered somewhat in a previous post, but I never got a clear answer. Each PLC has a digital output module with 32 outputs (4 groups of 8). We are only using 2 groups of the 4 (16 outputs) in each cabinet. 1 group is powered by a separate E-Stop circuit and power supply, the other group is powered by a local supply that is not cut upon E-Stop. Each output group is isolated from each other and there is an allowable 75VDC between groups according to the data sheet. Would it still be a good idea to tie the 0V from the safety circuit supply and the local supplies together? Or is there any potential issue with doing this?
4) We are using Siemens 24V S7-1500 8A power supplies, which have short circuit protection built-in. Should we still add a circuit breaker to the output side of the supply? Is this really necessary or good practice? If so, would you connect it directly to the output of the supply, with the other end of the breaker going into terminal blocks?
5) Just out of curiousity, we are using 2 power supplies in parallel for the safety circuit outputs. Each PS is setup with a separate C10 MCB at the input. If one of these trips and it is not immediately corrected, it will keep power to the safety circuit but only provide an output of 8A max, which bothers me. I'm wondering if this is really an issue, and if it would be better to run both of these off of a single breaker, or if it is fine how it is. Upstream of these 2x C10 breakers is a C20 breaker already, if tripped it would shut off power to pretty much all cabinets except the MCC. Any comments here would be appreciated.