.
Neptune Series
Isolation Transformers


3-Phase to 6-Phase Wye Balanced 120 Volt Output
Product Information
U.S. Pat No. 5,969,510


The most cost effective and efficient way to evenly distribute single phase balanced power from a delta or wye AC distribution system in a building is with a Neptune (3-phase / 6-phase wye) balanced isolation transformer.  Where properly installed, these transformers effectively eliminate objectionable grounding currents and harmonic noise in sensitive electronic facilities.

               
A three phase feeder (originating from a delta or wye system) is connected to the delta primary of the transformer (H1, H2, H3)
(No neutral wire is used)
Neptune Schematic
 
Power is magnetically coupled to three balanced 120-volt output coils set in rotation around the three primary phases.  Each output coil is center tapped then all three center taps are connected at the common output lug (x0) on the transformer.  (This is where the system is to be grounded.)  The remaining 6 output terminations (2 from each secondary coil) are then paired up in sequence (x1/x4, x2/x5, x3/x6) and terminated at 6 output landing lugs.  Three output circuits are created with a shared grounding reference, each distributed through three single phase panel boards utilizing 2-pole circuit breakers throughout the system.  Equi=Tech provides a Microsoft Word Document containing Balanced AC Wiring Specifications for architects and engineers that can be used in part, cut and pasted into "E" pages in plans for many different types of engineering projects.


Neptune Advantages
 

  • It is economical and easy to balance the single-phase load when using standard 3-phase commercial power distribution systems.  Article 647 in the 2002 NEC prescribes wiring methods that are to be used in balanced AC power installations.
  • When the transformer is connected to non-linear loads, the direction of reactive currents created are opposite (with respect to ground) and equal in the balanced secondary windings of the transformer. Therefore the magnetic field generated by the reactive load currents cancels out as common mode information and thus remains isolated from the transformer's primary circuit.  This assures a higher power factor on the primary side of the transformer, unaffected by non-linear loads. 
  • The most recent IEEE Green Book (2006 ed.) recommends balanced power for maintaining low noise grounding in data processing facilities.
  • These transformers may also be extended to be used with most commercial luminaires (such as fluorescent lighting systems) that are a prime source of power distortion, power factor loss and harmonic noise as well as producing unacceptable levels of EMI/RFI.  Neptune transformers provide a common mode noise rejection solution for attenuating these problems.
  • There is a single grounding reference point for all three single phase outputs (the center tap) and there are no grounding currents present.  If all of the electronic equipment power supplies are balanced, all of the equipment chassis will be at unity potential.  Expensive signal reference grounding systems are rarely required, even in the largest facilities.
  • Reactive currents and noise are greatly reduced in a large facility at minimal expense with maintenance costs also at a bare minimum.  Issues associated with reactively loading a 3-phase distribution system with various single phase non-linear loads will no longer be problematical.
 
Technical Engineering Notes

The precision degree to which these transformers' output windings are balanced means that there will be less line to line current phase shift under load (with respect to ground) which provides for a significantly broader bandwidth of common mode noise attenuation.  Unlike similar transformers of their type, Neptune transformers are highly tuned devices wound with proprietary winding methods designed to achieve near perfect balance.  The secondary windings are virtually a mirror image of one another.  This means that the shorter wavelength of high frequency harmonics does not limit these transformers' capacity to effectively attenuate high frequency noise.  High frequency harmonics, aside from having a negative effect on the performance of sensitive electronic systems, are also a waste of power.  It's not unusual to read voltage between neutral and ground in conventional 3-phase wye distribution systems -- most often several volts but sometimes as much as 30 volts or more.  Voltage between neutral and ground found in typical 3-phase wye distribution systems is an indication of an extreme presence of harmonic currents.

As finer and finer resolution is achieved by digitally based electronic systems of all shapes and sizes, the need for ever more refined power quality will continue to grow in importance.  Perhaps one day, balanced AC power may be a mandatory requirement because of the technical advantages it provides.  When Neptune transformers are used, no other power conditioning device or active filtering system is required to maintain the cleanest possible active current wave form and the most noise-free signal reference in any technical facility.  Sensitive electronic equipment of all varieties performs more accurately and reliably.  The difference in equipment performance (as often reported to us by users) is astonishing.

Another major benefit provided by Neptune transformers is significant for economic reasons.  When reactive load current is canceled in the manner described here, a higher power factor is maintained.  [kW2 + kVAR2 = kVA2] where kW approaches kVA as kVAR approaches 0.  Reactive currents are cancelled out when the system is loaded.  Current and voltage will remain in phase (higher power factor) to a greater degree as more as more impedance loads are switched over to a balanced power distribution system.  Utility company penalties for power users with a low power factor are greatly reduced if not altogether eliminated.  With a more phase coherent AC supply present, all types of AC loads will use electricity more efficiently.  Stated in simple terms, for electrical power to perform any task, both current and voltage must be in phase to one another.  To the degree that they are not, nothing will happen.  To the degree that they are, the desired effect is achieved.  The bottom line is, less kVA needs to be generated to perform a task when power remains more phase coherent.  Higher power factor system wide is an inherent quality of the balanced power architecture.  

As has been described here, wide scale use of Neptune transformers across bulk utility power systems at the user level will provide increased power efficiency for everyone.  Less kVAR and high power factor is also more "gentle" on power generation and distribution systems which lowers maintenance and other related bulk power distribution costs.  Perhaps most important of all, reducing the need for utility companies to "compensate" for low power factor by producing more power to offset low efficiency will result in the savings of untold millions in fuel costs.

Among the many advantages attributed to Equi-Tech balanced AC isolation transformers, they are also environmentally friendly.
 

Transformer Specifications
 

. Click on a transformer size for more information
Standard NEMA sizes are listed below
(For additional transformer sizes & voltage requirements, consult with factory)

kVA

15 - 30 - 45 - 75 - 112.5 - 150 - 225 - 300 - 500 - 750
.(Please be patient while we assemble all of the information to post here -- Thank you)

UL     ETL

All balanced power products shown here are manufactured under one or more of the following
U.S. Patents: 6,060,876- 5,969,510 - 5,892,667 - 5,640,314 - 6,278,266 -Other U.S. & International Pats. Pend.

E-Mail Technical Sales Assistance


(c) Copyright 1996, 2001, 2006 Equi=Tech Corporation all rights reserved