FujiFilm FRENIC5000G11S Series, Техническая информация

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Chapter 8
Appendix 1. Advantageous Use of Inverters (with regard to Electrical Noise)
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1.3 Noise prevention measures
As noise prevention measures are strengthened, they become more effective. With the use of appropriate measures, noise
problems may be resolved simply. Therefore, it is necessary to implement economical noise prevention measures according to the
noise level and the equipment condition.
1.3.1 Noise prevention treatments prior to installation
Before inserting an inverter in a control panel or installing an inverter panel, it is necessary to consider the noise. Once noise
problems occur, great expenditures of apparatuses, materials and time are required.
Noise prevention treatments prior to installation are listed below.
q
Separation of the wiring of the main circuit and control circuit
w
Insertion of the main circuit wiring into a metal pipe (conduit pipe)
e
Use of shielded wire or twisted shielded wire in the control circuit.
r
Implementation of appropriate grounding work and grounding wiring.
These treatments can avoid most noise problems.
1.3.2 Implementation of noise prevention measures
There are two types of noise prevention measures, those that correspond to the propagation route and those that counteract the
effect of noise on the receiving side (side that is adversely affected by the noise).
The basic measure to lessen the effect of noise on the receiving side is to:
q
Separate the main circuit wiring from the control circuit wiring, making it more difficult to receive noise.
The basic measures to lessen the effect of noise on the generating side are to:
w
Install a noise filter to reduce the noise level.
e
Apply a metal conduit pipe or metal control panel to confine the noise level, and
r
Apply an insulated transformer for the power supply to cut off the noise propagation route.
Table 1 lists the methods for preventing the noise problems, their goals and the propagation routes.
Next, noise prevention measures are presented for the inverter drive configuration.
(1) Wiring and grounding
Separating the main circuit and control circuit as much as possible, both inside and outside the control panel, and the use of
shielded wire and twisted shielded wire, makes it more difficult to receive noise and allows wiring distances to be minimized
(refer to Fig. 7). Take notice that the wiring of the main circuit and control circuit does not become bundled or parallel wiring.
For the main circuit wiring, a metal conduit pipe is used and grounded through a grounding wiring to prevent noise propagation
(refer to Fig. 8).
The shield (braided wire) of the shielded wire is securely connected to the base (common) side of the signal line at only one
point to avoid the loop formation resulting from a multi-point connection (refer to Fig. 9).
The grounding is effective to not only to reduce the risk of electric shocks, but also to block noise penetration and radiation.
Corresponding to the main circuit voltage, the grounding work should be No. 3 grounding work (300V AC or less) and special
No. 3 grounding work (300 to 600V AC). Each ground wire is to be provided with its own ground or separately wired to a
grounding point.
Fig. 7 Method of separating wiring
Signal line
Signal line
Shielding plate (steel plate) Shielding plate (steel plate)
Power line
In a case of duct
In a case of rack
Chapter8-1(P1˜10).p65
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