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ZSF - Zero Sequence Filter (

zero sequence harmonic

zero sequence harmonic

Applicable Loads Computer, OA equipments, Electronic fluorescent lamp, Single Phase SCR heater and UPS etc. Applicable System Single phase nonlinear loads on Three phase four wire system Applicable Locations Office/Commercial building, School, Shopping Mall, Department store, Apartment, Hospital, Factory etc.

Reduce Line Current The ZSF can reduce rms value of line current by reducing zero sequence harmonic current that is produced by single phase non-linear loads in three phase four wire system. Reduce Neutral Current The zero sequence current in line make a large neutral harmonic current by trebling.
The ZSF can reduce this large neutral current up to 90% depend on ZSF location. Meet IEEE Std.519-1992 The ZSF enable most single phase non-linear loads to comply with both the voltage and current distortion limits of IEEE Std.519-1992 and other international limits such as AS-2279, EN61000-3-4, and BS G5/4.

Protect loss and reduce capacity because of circulating effects by zero sequence harmonic current in transformer.
Protect heating and loss of line and neutral cable that is effected by zero sequence harmonic current.
Reduce unbalance of line current.
Improve power factor.
Reduce system loss.
Reduce K-factor rating of load current at main transformer.

Economical and stand-alone solution The ZSF is standardized up to 3000A. Therefore, if maximum neutral current can be figure out,
the site survey and system simulation before installing are not necessary.

Compact and easy-to-install. Quite operation and proper ventilation. Neutral size for three times of line current. Standardized up to 3000A (based on neutral current). Ammeter displaying the neutral current in option. Neutral impedance adjuster upon request.

Duplicating Principle of zero sequence harmonic The zero sequence harmonic current produced by single phase non-linear loads can treble in neutral line and make problems.

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Removing principle of zero sequence harmonic
Up to 90% maximum of zero sequence harmonic current flow into zero sequence transformer in the ZSF because zero sequence transformer is specially designed to have very low zero sequence impedance. This can effectively be moved zero sequence harmonic currents upstream from the ZSF.

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Select Zero sequence Filters based on the maximum neutral current at the location that ZSF will be installed.

Catalog Number Currents in neutral [A]
ZSF22030 30 350 500 500 70 Fig A
ZSF22060 60 350 500 500 85 Fig A
ZSF22100 100 600 400 850 150 Fig A
ZSF22150 150 650 450 900 180 Fig A
ZSF22300 300 800 450 1000 350 Fig B
ZSF22450 450 800 500 1200 400 Fig B
ZSF22600 600 800 1500 2350 800 Fig B
ZSF221000 1000 1100 1500 2350 1500 Fig B
ZSF223000 3000 1100 1500 2350 3000 Fig B
Table 1. Selection table of the ZSF

Current = Maximum neutral current
W = Width, D = Depth, H = Height
All weight and dimensions are subject to change without notice.
    Recommended Ratings = Ip 3 (Ip = Phase currents in rms)

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Step1. Find proper location
Find proper location where the ZSF can be installed. Reduction ratio can be maximized if the ZSF is installed as close as possible to load side.
Step2. Measure max current at neutral line
Measuring max current at neutral line is very important to choose the rating of ZSF. If the rating of ZSF should be decided without measured current or design process, three times of max current at phase can be considered as max current at neutral line.
Step3. Choose the rating of ZSF at Table 1
Choose the proper rating of ZSF at Table 1 with max current at neutral line.

- Installed Product: ZSF22600 [600A] - Problem: an electricity failure by a large amount of neutral current produced by non-linear loads

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Installing result: 75% reduction of neutral current

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- Installed Product: ZSF2260 x 5 [60A] - Problem: an electricity failure by computer, OA equipment, and other single-phase non-linear loads - Installing result: 84% reduction of neutral current

Installation Placee Product Neural Current Reduction (%)
1/2 Floor
3/4 Floor
5/6 Floor
7/8 Floor
ZSF 22060
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