DCS電源觸發板SDCS-PIN-3B工業模塊
長度超過3m的數字信號電纜和模擬信號電纜必須屏蔽。每個屏幕必須
兩端用金屬夾連接(見圖5.2-4),或直接在干凈的金屬表面上進行比較,如果兩者
接地點屬于同一接地線。否則,電容器的一端必須接地。在變流器柜內
這種連接必須直接在金屬板上進行
靠近端子(見27),如果電纜來自外部也在PE桿上(見25和26)。在電纜的另一端屏幕必須與信號外殼良好
發射器或接收器。如果電纜過長,則必須使用帶屏幕的電纜易受EMC環境條件影響的距離(>20m)。電纜可以具有例如優選由銅或鋁制成的編織或螺旋屏蔽。轉移電力電纜的阻抗ZT必須小于0.1?/我在頻率范圍高達100 MHz,以確保有效減少發射并顯著提高抗擾度。這個必須使用導電良好的金屬夾直接按壓屏幕
緊靠變頻器柜的安裝板或PE條(見24)。另一個連接選項是通過EMC套管。那里接觸面應清潔并盡可能大。體育電線可與PE桿上的普通電纜插座連接。
至電樞和勵磁繞組的屏蔽電纜
導致最低噪聲水平。如果不需要屏幕(見13),則電樞電流電纜
必須是四線電纜,因為需要兩根導線作為從電機到射頻濾波器的寄生射頻電流的導體
在隔間里。如圖5.2所示,非屏蔽勵磁電流電纜F必須直接沿電樞電纜A安裝-5.2線電纜就足夠了。
圖5.2-5勵磁電流布置橫截面圖
電纜F和電樞電纜A
根據26所述的布置已經用20 m長的電機電纜,從而滿足傳導發射要求。
如果到電樞的連接由單線電纜制成,然后,n+1根PE電纜必須與它們一起布置在電纜軌道上,如圖5.2-6所示,其中n=4。
The cables for digital signals, which are longer than 3 m and all cables for analogue signals, must be screened. Each screen must be
connected at both ends by metal clamps (see figure 5.2-4) or
comparable means directly on clean metal surfaces, if both
earthing points belong to the same earth line. Otherwise a capacitor must be connected to earth on one end. In the converter cubicle
this kind of connection must be made directly on the sheet metal
close to the terminals (see 27) and if the cable comes from outside
also on the PE bar (see 25 and 26). At the other end of the cable
the screen must be well connected with the housing of the signal
emitter or receiver.Power cables with screens are necessary, if they run over long
distances (>20 m) where they are susceptible to EMC environmental conditions. The cable may have e.g. either a braided or spiral screen made preferably of copper or aluminium. The transfer
impedance ZT of the power cable must be less than 0.1 ?/m in the
frequency range up to 100 MHz, in order to ensure an effective reduction of emission and a significant increase of immunity. The
screen must be pressed by a well conducting metal clamp directly
against the mounting plate or the PE bar of the converter cubicle
(see 24). Another connection option is via EMC sleeve. There the
contact surface shall be clean and as large as possible. The PE
wire can be connected with a normal cable socket at the PE bar.
Screened cables to the armature and to the excitation winding
cause the lowest noise level.If a screen is not necessary (see 13) the armature current cable
must be a four-wire cable because two wires are needed as conductors for the parasitic RF currents from the motor to the RF filter
in the cubicle. The unscreened field current cable F must be installed directly along the armature cable A as shown in figure 5.2-
5. A 2-wire cable is sufficient.
Figure 5.2 - 5 Cross-sectional view of arrangement of field current
cable F and armature cable A
The arrangement according to 26 has been tested with a 20 m long
motor cable with the result that the conducted emission requirements are fulfilled.
If the connections to the armature are made from single-wire cables, especially if n parallel wires are necessary for higher currents,
then n+1 PE cables must be arranged together with them on a cable rail as shown in principle by the figure 5.2-6 with n=4.