ZN/ZNyn/YNd — earthing (neutral-forming) transformer up to 130 kV
The earthing (neutral-forming) transformer creates a physical neutral in networks where the substation's power transformer has a delta-connected low-voltage winding.
- Voltage
- up to 130 kV
- Neutral current
- up to 1000 A
- Duty
- continuous or short-time (2 h)
- Connection
- ZN, ZNyn11/5 (with auxiliary winding), YNd (open delta, five-limb)
Price, availability and lead time on request. We help with analogue selection, customs clearance and delivery.
Description
The earthing (neutral-forming) transformer creates a physical neutral in networks where the substation's power transformer has a delta-connected low-voltage winding. The neutral of the earthing transformer has low zero-sequence impedance and is suitable for any earthing method: solid, through a resistor (NER), or resonant — through an arc suppression coil. The transformer can be equipped with a 400/420 V auxiliary winding and used simultaneously as the substation's station-service transformer. Versions are produced with connections ZN (zigzag), ZNyn11/5 with a station-service winding or with a low-voltage load-break switch, and five-limb YNd transformers with an open delta — for earthing the neutral of small industrial networks. Design: sealed oil-immersed transformer (ONAN cooling) for outdoor and indoor installation, or a dry cast-resin version; supply with a built-in neutral earthing resistor and a load-break fuse on the station-service side is possible. HV and neutral bushings are plug-in type Elastimold, DIN or Pfisterer; lifting lugs and optional wheels for installation on a foundation are provided. Main characteristics: voltage up to 130 kV, current up to 1000 A, continuous or 2-hour operation, 50 or 60 Hz, insulation for rated voltage (IEC 60076-3), temperature −40…+40 °C, transformer oils Nynas Nytro Taurus, Starke & Sohn Transformer Oil U or ester fluid Midel 7131. Acceptance tests cover checking the dielectric strength of HV and LV insulation, measurement of losses, and verification of rated voltage and current; type tests are performed per IEC 60076-1 (temperature rise, dielectric tests). The active parts are manufactured by a German partner plant — one of the largest transformer manufacturers in Europe; the manufacturer has supplied earthing transformers jointly with a German partner plant since 1991 as part of a set of neutral-mode equipment together with arc suppression coils and resistors. A typical supply is an earthing transformer and an arc suppression coil installed side by side on a common substation foundation.
Technical specifications
| Voltage | up to 130 kV |
|---|---|
| Neutral current | up to 1000 A |
| Duty | continuous or short-time (2 h) |
| Connection | ZN, ZNyn11/5 (with auxiliary winding), YNd (open delta, five-limb) |
| Secondary auxiliary winding | 400/420 V |
| Cooling | ONAN (sealed oil-immersed); AA/AFA (dry) |
| Frequency | 50 or 60 Hz |
| Temperature | −40…+40 °C |
| Active part manufacturer | Germany |
| Tests | IEC 60076-1, IEC 60076-6 |
Replacement for
ФМЗО, ТМПС (neutral-forming ZNyn 6–35 kV); at 110 kV — no direct analogue
selected by purpose and main parameters, please confirm with our manager
Request a price and lead time
ZN/ZNyn/YNd — earthing (neutral-forming) transformer up to 130 kV. We reply within one business day.
Or email sales@usk.ua or call 044 339-50-20.
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