Seeking advice on 220V power supply solution
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There are 9 220V electrical devices, each with a power rating of 4KW. Power supply scheme: Transmission via 380V bus, with cables of 5 x 16 square millimeters. For explosion protection at the site, use explosion-proof distribution boxes to supply power to 9 electrical devices; decide whether to use explosion-proof control cables of the power type or the lighting type. Is there also no mistake in the cable selection?
If the load does not require the use of cables simultaneously, such boxes are considered hybrid boxes for lighting and power supply. The reason for this is that there is no motor circuit; instead, the lighting circuit has a higher voltage. These boxes are called lighting boxes. The difference between a power supply box and a lighting box lies in the breaking capacity of the circuit breaker and the load it can handle.
I haven’t figured out what exactly the original poster wants to ask :L
This post was last edited by zhaohh3211 on 2010-10-28 03:13. Reply to 3# zyz8438: I made a typo. Question 1: Was the cable chosen incorrectly? Question 2: Which type of explosion-proof control box should be chosen? My load works all together.
Reply to 2# So handsome. When devices operate simultaneously, it seems that the methods for calculating cables differ for 380V equipment and 220V equipment. The 9 electrical devices are evenly distributed across three phases, with 12 KW per phase; based on the calculations, a cable of slightly more than 10 square millimeters in cross-sectional area is required.
This post was last edited by zyz8438 on 2010-9-23 at 10:46. The current for a 12kW single-phase load is over 50A, and since all of your loads operate simultaneously, isn’t a 16mm² cable a bit too small?
I checked and found that the current-carrying capacity of a 16-square millimeter cable is 91 amps, so there should be no problem. Could it be that the neutral wire needs to have a larger cross-sectional area? Then what type of cable should I choose? Here is the information found: The maximum safe current for ordinary copper wires is as follows: the safe current-carrying capacity of a 2.5 square millimeter copper power wire is 28A. The safe current-carrying capacity of a 4 mm² copper power cable is 35A. The safe current-carrying capacity of a 6 mm² copper power cable is 48 A. The safe current-carrying capacity of a 10 mm² copper power cable is 65A. The safe current-carrying capacity of a 16 mm² copper power cable is 91 A. The safe current-carrying capacity of a 25 square millimeter copper power cable is 120A.
This post was last edited by zyz8438 on 2010-10-2 20:51. The current-carrying capacity of a cable depends not only on its cross-sectional area but also on the way it is installed! Is the cross-section of the neutral wire sufficient?
My electrical device is a heating resistor, 9 of them, all the same. The load should be the same, right.
This post was last edited by zhaohh3211 on 2010-10-28 03:16. There is only a factor of three relationship between single-phase and three-phase; it’s not a triple relationship, so don’t fall into this misconception.
You also need to consider whether your three-phase load is evenly distributed