DCS power supply issue

I’m not sure about anything else, but the entire Siemens Sitop series features an adjustable power output voltage. It is adjustable between 20V and 28.8V. Generally, when the line length is between 200-400 meters, it is recommended to increase the value by about 10%; for lengths of 400-500 meters, an increase of 15% is suggested. Although the power supply limit can be adjusted to 20%, which is 1.2 times the rated output (DC24V), it is not recommended to do so. If the distance is over 500 meters, it’s best to use a relay to convert DC24V to AC220V before powering the equipment on site. All of the above are empirical values, representing roughly similar concepts; you can adjust them within a certain range based on these values to find what works best for your specific situation. Because the attenuation of different cable types, such as parallel and twisted pairs, varies; the same is true for shielded and unshielded cables. Cables with a larger diameter also differ from those with a smaller diameter. Adjust it yourself: at the end of the cable, where there is a load in the circuit, just use a multimeter to check it. Several series of power supplies from Mingwei are also adjustable.

If the distance is long, a small 24V power module can be installed on-site, powered by 220V supplied to that location

The voltage of most power supplies can be adjusted, but it is necessary to calculate the power accurately taking into account the conditions on site. For high-performance requirements, a redundant power supply system can be used.

Agree with the third floor’s suggestion: use the 220V power available on site, install a 24V power module there, and if the control points are concentrated, individual IO stations can be set up. This post was last edited by zhaohh3211 on 2009-3-2 11:06.]

The site where I am working is explosion-proof, so it’s rather complicated to install power modules there. Moreover, if 220V AC is used, a partition needs to be added to the cable tray. By the way, regarding what you mentioned about \"Spread Your Wings and Fly\": for typical wire lengths of 200–400 meters, it is recommended to increase the value by around 10%; for lengths of 400–500 meters, an increase of 15% is suggested. What cable cross-sectional area are you based this on? Is it 2x1.0, 2x1.5, or 2x2.0?

The site is explosion-proof! Say it earlier! It depends on the cross-sectional area of the cable you are using, the amount of current flowing, and the length of the circuit. By calculating the line losses, you can determine how much voltage needs to be increased! For a 1.5 square millimeter wire, the resistance is 13 ohms per kilometer; for a 2.5 square millimeter wire, it’s 8 ohms per kilometer. If a higher-quality power supply is used, it usually has an automatic wire loss compensation function (the power supply has two terminals labeled S+S-). These are the control and sampling terminals of the power supply. By connecting these two terminals together with a jumper, and then removing that jumper to connect the wires where you need them, you can achieve the desired result. For more details, please refer to the power supply’s manual! This post was last edited by liuei on 2009-3-4 21:14]