 |
|
|
The power lines contain a mix of normal-mode noise (noise between lines) and common-mode noise (noise between power line and ground). This means that noise filters need to reduce both noise components.
In addition, noise entering power lines includes not only noise from a variety of high-frequency emitting equipment, such as inverters, but also broadcast and other radio waves. As a result, power line noise covers a broad bandwidth from low frequencies to high frequencies (several tens of kHz to several tens of MHz).Such conductive noise can be effectively reduced by the use of noise filters.
In general, noise filters will be more effective when they are grounded.However, it is often impossible to ground electronic and communication equipment used in general households or offices. Even if it is possible, reliable grounding cannot be ensured. Because of this, it is often the case that the performance stated on in the product catalog cannot be obtained and/or effective measures against noise cannot be taken. (See Figure 1.)
To solve these problems, Sanritz's power line noise filters contain a compound common-mode choke coil that was developed jointly with NTT. They require no grounding, cover a wide bandwidth, and ensure high attenuation.In addition, low-frequency filters for protection from inverter noise are also available.
|
Figure 1
 |
Comparison of common-mode attenuation characteristics
between Sanritz noise filters and general noise filters in different grounding conditions. |
|
Sanritz has developed filters for protection from very low-frequency noise with attenuation characteristics of 40 dB min at 100 Hz to 100 kHz and filters with attenuation characteristics of 40 dB min in the inverter noise frequency range of 10 kHz to 1 MHz.High-frequency noise filters are also available, with attenuation characteristics of 30 dB min at 100 kHz to 50 MHz.Since the filters are fitted with a modular jack, they can be easily connected and installed. |
* For further information, see the page explaining each type of noise filter.
EMC Products
[Safety standard]
(amperage)
|
Terminal
|
Type of noise
|
|
|
 |
|
|
outlet |
|
|
|
|
|
outlet |
|
|
|
|
|
Faston
|
|
Screw
|
|
|
|
|
|
|
|
|
|
Screw
|
|
|
 |
|
|
MJ
|
|
|
|
|
|
MJ
|
|
|
|
|
20 dB min in normal/common mode
|
|
20 dB min in common mode
|
|
|
Note 1: Certified in accordance with Electrical Appliance and Material Safety Law
Note 2: Certified in accordance with UL, CSA, or  (For further information, see the page explaining each type of noise filter).
• Common-mode performance measuring circuit
|
|
• Normal-mode performance measuring circuit
|
 |
Caution |
• Since no overcurrent protector is contained in filters (E, K, and J series) that are installed on the protected equipment, insert a fuse, breaker, or similar means suitable for the current rating on the power supply (input) side.
|
Warning |
• In filters that are to be installed on protected equipment, an X capacitor is included between phases, but no discharge resistor is.If the protected equipment does not contain any discharge element, connect a discharge resistor; otherwise, an electric shock may occur.
|
Danger |
• Make sure that the current and voltage ratings are not exceeded.Otherwise, a fire, failure, or other problem may occur.
|
• Separate the input and output wirings of EMC products apart the longest possible distance.Do not bundle the input and output wirings together or place them in parallel.
• The installation location should be as close to the noise source as possible.
|
|
|
|
|
