Download Print PDF
If you have a delta or ungrounded wye connected distribution system application where a neutral ground path is required via a custom neutral grounding transformer or ground isolation transformer…Olsun Electrics can do that!
Olsun can design, manufacture and supply a dry-type neutral grounding transformer, or ground isolation transformer, in either a Zig Zag or a Two Winding configuration for your particular application.
Zig Zag Transformer Configuration Two Winding Configuration
A properly designed and installed grounding transformer will protect an isolated three phase system in the event of a line-to-ground fault by providing a low impedance path to ground for ground fault currents to flow while prohibiting voltage rise in the un-faulted phases and accommodating the connection of phase-to-neutral loads if required.
To provide a quotation or to design and manufacture your required ground isolation transformer, Olsun Electrics requires certain application and system data.
Please take a brief moment and use the “Check List” below to gather the following (13) basic pieces of Grounding Transformer information:
- Winding configuration; either Zig Zag or Two Winding.
- Voltage(s) and BIL; The line-to-line value of the system to which the grounding transformer is to be connected. If a two winding grounding transformer is required, the secondary voltage must be provided as well.
- Continuous neutral current.
- System available neutral fault current and duration; example 500 amps for 10 seconds, 4000 amps for 2 seconds.
- Zero Sequence impedance percentage.
- Per phase impedance in Ohms.
- Per phase resistance in Ohms.
- X/R ratio; typically a value > 4.0.
- Special application conditions; i.e. 2000 MASL, etc.
- Enclosure construction or NEMA designation preference; i.e. high security compartmentalized padmounted, standard ventilated or substation design, special paint color, etc.
- Terminal connectivity preference; i.e. dead front, live front, conventional terminals, etc.
- Winding material; CU if not specified.
- Transformer temperature rise; 150° C if not specified.
NOTE! You may have noticed that “kVA” is not one of the parameters requested. Grounding isolation transformers are sometimes referenced by a kVA, but technically, they should not be so referenced unless they are providing auxiliary power in some way.
A neutral grounding transformer in the conventional sense is to be “labeled” based on the system continuous current and fault current it is designed to carry.
Download Print PDF