Based on three aspects: no-load loss, load loss, and total cost of ownership, we analyze the selection logic and recovery period calculation method for upgrading from S13-M to high-efficiency level S20/S22.
The S13-M series has long been the main choice for distribution networks. After the tightening of procurement standards, more and more projects require Level 1 energy efficiency (S20/S22). The key difference lies in the loss structure: amorphous/high-magnetic permeability silicon steel and better magnetic density designs further reduce no-load losses, which is most evident in distribution network and station nodes with long-term power operation and low load rates.
We recommend following a three-step approach based on total cost of ownership when selecting equipment: First, obtain the project load curve to estimate the average annual operating hours and load rate; second, calculate the annual power losses for S13 and S20/S22 separately (no-load losses are calculated based on 8760 hours, while load losses are calculated based on the square of the load rate); third, convert the annual operating electricity costs into local electricity prices. Generally, the purchase price difference can be recovered within 3–5 years, after which there is net profit. In scenarios with low load rates—such as photovoltaic support systems, backup circuits, and seasonal loads—Level 1 energy efficiency should be prioritized.
For export projects, it is necessary to verify loss data and acceptance criteria: The tolerance range for IEC 60076 routine tests differs from the actual measurement criteria in some national energy efficiency regulations. Determining which data to use and how to indicate tolerances is a common issue during customs clearance and acceptance. It is recommended to clearly list the test standards in the technical deviation form.
The same logic applies to the dry-type product line: the choice between SCB13 to SCB18 and SCBH amorphous routes is also a combination of loss considerations and fire safety constraints. You need to conduct calculations based on your load curve: sales@fgtransformer.com.
Finally, here is a quick judgment tip: For nodes with a load rate below 40% and annual operation exceeding 6000 hours, Level 1 energy efficiency has the shortest payback period and should be upgraded first; for two-shift industrial and commercial loads, S13 remains the optimal solution. Include these two criteria along with the calculation table in the internal procurement guidelines, which is much more efficient than discussing each project individually.
Our company can provide filled comparison calculations (including explanations of both IEC and energy efficiency regulation test criteria) based on the project load curve. You can directly use them during the bidding process: sales@fgtransformer.com.
Beyond price and timeline, there are clear answers to three things that procurement peers care about: Technical clarification is closed within one round (each deviation is replied in writing); tests are verifiable (routine/type tests are arranged according to IEC 60076 and can be witnessed by a third party); batches are traceable (factory serial numbers correspond one-to-one with reports). Please submit these thirty-page document templates for evaluation first; this is more effective at avoiding later rework costs than just comparing prices—query entry: sales@fgtransformer.com.
Why choose this configuration? Lessons from rework in similar projects focus on three areas: no recalculation of frequency and grid parameters, estimation of anti-corrosion level based on experience, and missing documentation until it reaches the port. The technical approach of this product is to pre-define these three issues as written conclusions, allowing verification item-by-item during the quotation stage.