Ask for pricing on reactors, transformers or harmonic filter by Email or phone call. Please fill in the requested information for each application.


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Harmonic Filters: A six-stage filter is shown as an example *

In large rectifier systems, we customize a switched multi-stage filter to meet the IEEE or IEC distortion and desired power factor requirements over the control range of the rectifier. We characterize your controlled rectifier with accurate estimate of harmonics before and after filter. See the sample report below for the extent of our design details.

For other applications such as plant power factor & THD control, the required specifications for the harmonic filter are:
1.    Line voltage and tolerance
2.    Line frequency and tolerance
3.    Line transformer kVA and impedance
4.    Line breaker and fuse ratings

5.    Power factor as is now and desired power factor after correction over the range of plant's electrical power loading
6.    Harmonics before the correction as they are now: each frequency and amplitude
7.    Desired Harmonics after correction: comply with IEEE519 or specify desired limit for each harmonic
8.    The ambient temperature, altitude and humidity
9.    The insulation class for the reactor or its required temperature rise (the lower the temperature rise, the higher the cost)
                                                                               Nomex            Polymide
Insulation Class    A      B        F       H        N       R       GP200    MW-16
Max Hot spot ⁰C   105    130    155    180    200    220    180         240
Avg. rise ⁰C            55      80      80    115     130     150     115         150

10.     The enclosure location and NEMA type (indoor, outdoor, NEMA 1, 3, 3R, 4, 4X etc.)
11.   Type of cooling: natural air or forced air, water or oil
12.    The interconnecting cable type, terminal type and outline to enclosure
13.    Enclosure size limits
14.    Any special switchgear or protection
15.    Mounting and lifting mode of enclosure (bottom fork lift or top eye bolt )



* Power Magnetronics Solutions™ staff use a fully customized Mathcad program to design and compare performance characteristics of various multi-pulse rectifier systems. Utilizing advanced computer tools, the company is unique in its profession by providing all of the above services under the same roof, thereby optimizing the integration of a large scale system and providing the client the convenience of working with a single source for their power supply and filtering requirements. 



1.    Rated power, kVA: 2000
2.    Number of Phases: 3
3.    Nominal Frequency and Tolerance: 60 Hz+/-0.5 Hz
4.    H-winding - Primary voltage and Tolerance: 13.8 kV +/-10%
5.    X/Y/Z windings - Number of Secondary windings and line-line voltages: 2 at 480 V/600 V

6.    Type of secondary load: specify if multi-pulse rectifier, furnace or any nonlinear load*
7.    Surge Rating: 95 kV BIL at primary
8.    Efficiency: minimum 99% at nominal load, 98% at 50% load
9.    No-Load losses: Max 5000 W
10.   Primary to secondary vector group (middle column above): YNynd5 
11.    Taps: Primary +/-2.5%
12.    Impedance voltage (at principal tapping): 10% 
13.   Type of cooling: natural air or forced air or water
14.   The ambient temperature, altitude and humidity: 40 C, 1000 ft., RH 50%
15.   The insulation class for (dry transformer) or average temperature rise (the lower the temperature rise, the higher the cost)

                                                                               Nomex            Polymide
Insulation Class     A      B        F       H        N       R       GP200    MW-16
Max Hot spot ⁰C      105    130    155    180    200    220    180         240
Avg. rise ⁰C               55      80      80   115     130     150    115          150

16.     The enclosure location and NEMA type (indoor, outdoor, NEMA 1, 3, 3R, 4, 4X etc.)
17.     The cable type, terminal type and entry to enclosure
18.     Enclosure size limits
19.     Any special switchgear and protection
20.     Mounting and lifting of enclosure (bottom fork lift or top eye bolt )
21.     Miscellaneous: overload rating, short circuit withstand, audible noise, etc.


* Due to questionable accuracy, we do not use the K-factor method for loss/thermal design of transformers with harmonics. Instead, we use actual or measured harmonics and using our MATHCAD design tools, calculate the harmonic losses and temperature rise.