Question 1

What is the difference between SCB18, SCB14, and SCB12 series?

Accepted Answer

The numeric suffix indicates the energy efficiency tier under GB 20052-2024: SCB18 = Level 1 (highest), SCB14 = Level 2, SCB12 = Level 3. Taking a 1250 kVA unit as reference, SCB18 cuts no-load loss by approximately 15% versus SCB14 and 28% versus SCB12. For continuous-duty applications, the higher first-cost of SCB18 is typically recovered through electricity savings within a few years.

Question 2

Why choose a dry type transformer instead of an oil immersed transformer?

Accepted Answer

Dry type transformers use epoxy resin insulation instead of flammable mineral oil, eliminating fire hazards and oil leakage risks. They are flame-retardant, self-extinguishing, and produce no toxic gases. This makes them preferred or mandatory for indoor installations, high-rise buildings, hospitals, metro stations, and data centers where fire safety codes prohibit oil-filled equipment.

Question 3

What insulation class should I select? Class F or Class H?

Accepted Answer

Class F insulation serves as the standard for general distribution projects. Class H insulation is advised for environments with elevated ambient heat, frequent heavy cycling loads, or areas lacking proper ventilation. Both adopt vacuum epoxy casting construction, while Class H features extra thermal buffer to withstand harsh operating scenarios.

Question 4

What do AN and AF cooling modes mean, and when is forced air needed?

Accepted Answer

AN (Air Natural) uses natural convection for continuous rated load. AF (Air Forced) engages fans to boost capacity by 30%-50% for short-duration peaks. For applications with predictable load spikes - motor starting, industrial cycles, or data center failover - the AN/AF dual-mode allows selecting a smaller rated unit without sacrificing peak performance.

Question 5

What protection degree (IP rating) should I choose?

Accepted Answer

IP20 is standard for clean, dry indoor environments. IP23 adds drip protection for condensation-prone areas. IP31 or higher suits dusty or semi-outdoor installations. For corrosive or coastal environments, custom enclosures up to IP54 with anti-corrosion coatings are available.

Question 6

Can the transformer be installed directly indoors without a dedicated transformer room?

Accepted Answer

Yes. Being oil-free, flame-retardant, and non-toxic, SCB18 units can be installed in basements, mechanical floors, or directly adjacent to load centers without a separate fire-rated room. This reduces civil construction costs and shortens low-voltage cable runs, lowering line losses and improving voltage regulation.

Question 7

What is the partial discharge level of your SCB18 transformers?

Accepted Answer

Vacuum epoxy resin casting eliminates internal air voids, keeping partial discharge below 5 pC at 1.5 times rated voltage - well within the IEC 60076-11 limit of 10 pC. Low partial discharge is critical for long-term insulation reliability and service life.

Question 8

How does the transformer withstand short-circuit forces?

Accepted Answer

Vacuum-cast coils form solid void-free composites of high mechanical strength. Complying with IEC 60076-5, SCB18 transformers withstand >=35 kA short-circuit current for 2s, resisting axial and radial electromagnetic forces without permanent deformation.

Question 9

What temperature monitoring and protection systems are included?

Accepted Answer

Each unit has a BWDK intelligent temperature controller with PT100 sensors embedded in each phase winding. It provides real-time display, fan startup, over-temperature alarm, and trip contacts. An RS485 Modbus interface is included for SCADA or building management system integration.

Question 10

What are the installation clearance and ventilation requirements?

Accepted Answer

Minimum 300 mm clearance on all sides for inspection and airflow; 500 mm or more for units above 1000 kVA. The installation room must provide ventilation sized to dissipate total loss heat at maximum ambient temperature. We provide detailed installation drawings and ventilation calculations for every project.

Question 11

Can the transformer operate at altitudes above 1000 meters?

Accepted Answer

Standard units are rated up to 1000 m. Above this, reduced air density affects dielectric strength and cooling. For 1000 - 4000 m, we apply altitude derating per IEC 60076-11 with reinforced insulation. Special plateau designs are available for sites above 4000 m - please provide your site elevation.

Question 12

Can SCB18 transformers handle non-linear loads such as VFDs and rectifiers?

Accepted Answer

Yes. For harmonic-rich loads, we design with a K-factor rating (K-13 or K-20) to account for additional eddy current heating. The Dyn11 vector group is recommended as it traps triplen harmonics in the delta primary. Please provide your load profile and harmonic spectrum for proper specification.

Question 13

Is the SCB18 transformer truly maintenance-free?

Accepted Answer

It requires no oil filtering, sampling, or replacement. Routine maintenance is limited to visual inspection, cleaning cooling ducts, checking connection tightness, and verifying the temperature controller - annually under normal conditions. This reduces maintenance costs by approximately 50% versus oil-filled equivalents.

Question 14

What is the expected service life of an SCB18 transformer?

Accepted Answer

Rated service life >30 years. Per the 6 deg C rule, every 6 deg C lower average winding temperature doubles insulation lifespan; operation under rated temp rise extends service life well past 30 years.

Question 15

What information should I provide to get an accurate quotation?

Accepted Answer

Please provide rated capacity, HV/LV voltage ratio, vector group, tap range, impedance, frequency (50/60 Hz), winding material (copper/aluminum), insulation class (F/H), cooling mode (AN/AN-AF), protection degree, installation environment (indoor/outdoor/altitude), and required certifications (like CE).

Product profile

Customization

Application

Phase

Model NO.

Core

Cooling Method

Winding Type

Certification

Usage

Frequency Characteristics

Shape of Core

Brand

Model No.

Rated Capacity

Rated Voltage(Hv Side)

Rated Voltage(Lb Side)

Vector Group

Tap Range

Winding Material

Core Material

Impedance Voltage

Temperature Rise

Insulation Level

Protection Class

Noise Level

Service Life

Warranty

Transport Package

Specification

Trademark

Origin

HS Code

Production Capacity

Key features

Company profile

About Our Factory & Business Background

Our Production Capability & Technical Expertise

Our Industry Experience & Global Business Record

Our Certifications, Standards & Industry Recognition

Product Q&A

Send Inquiry

You may also like