DELIXI BK300 Control Transformers: BK300D01

Technical Dossier

Product Details And Specifications

DELIXI BK300 Series: Comprehensive Module Range and Technical Overview

The DELIXI BK300 series of single-phase control transformers is a foundational component class deployed across heavy industrial sectors globally, including petrochemical plants, thermal and nuclear power stations, steel mills, and continuous-process refineries. Manufactured by Delixi Electric Co., Ltd. — one of China's largest low-voltage electrical apparatus manufacturers — the BK300 range provides reliable step-down voltage conversion for machine tool control circuits, PLC input power rails, relay logic panels, and auxiliary equipment circuits operating at 36V, 110V, 127V, 220V, and 380V. The series is rated for continuous duty in ambient temperatures from -5°C to +40°C and complies with GB/T 5585 and IEC 61558 standards. Its compact DIN-rail and panel-mount form factors make it a standard specification item in Chinese-manufactured CNC machinery, injection molding equipment, and conveyor drive panels exported worldwide.

The Evolution of BK300 Architecture

The BK300 designation follows the Chinese national standard naming convention for single-phase control transformers (BK = 变控, control transformer; 300 = VA capacity class). Early BK300 units produced in the 1990s used E-I laminated silicon steel cores with varnish-impregnated windings and screw-terminal connection blocks rated to 6A. These units were designed for 50Hz grid infrastructure and were not rated for 60Hz operation without derating. By the mid-2000s, Delixi revised the BK300 line to incorporate improved grain-oriented silicon steel laminations, increasing efficiency to ≥95% at full load and reducing no-load losses. Terminal blocks were upgraded to cage-clamp designs on higher-capacity variants. The BK300D sub-series introduced dual-primary winding configurations, allowing field selection between 220V and 380V primary inputs via jumper links — a critical feature for export machinery destined for markets with mixed grid standards. Current production BK300 units carry CCC (China Compulsory Certification) and are compatible with downstream 24VDC SMPS, relay coil circuits, and solenoid valve drivers. For installations where the BK300 series has reached end-of-life or is no longer available through standard distribution, DriveKNMS maintains a verified stock of both current-production and legacy units.

BK300 Full Catalog & Functionalities (SKU List)

The following SKUs represent the verified BK300 series range. Each unit is a single-phase, 50Hz control transformer with copper windings unless otherwise noted.

BK300D01: 50VA, dual primary 220V/380V, secondary 36V/110V — standard machine tool control circuit transformer.
BK300-50VA: 50VA, single primary 380V, secondary 110V — relay panel auxiliary power supply.
BK300-100VA: 100VA, primary 380V, secondary 110V/220V — mid-capacity control circuit isolation transformer.
BK300-150VA: 150VA, primary 380V, secondary 36V/110V — conveyor and packaging line control power.
BK300-200VA: 200VA, primary 380V, secondary 110V — injection molding machine auxiliary circuit supply.
BK300-250VA: 250VA, primary 220V/380V, secondary 110V/220V — dual-voltage output for mixed relay/PLC panels.
BK300-300VA: 300VA, primary 380V, secondary 110V — high-load relay logic and solenoid valve bank supply.
BK300-400VA: 400VA, primary 380V, secondary 36V/110V/220V — multi-tap output for complex machine tool panels.
BK300-500VA: 500VA, primary 380V, secondary 110V/220V — large CNC machine control cabinet primary isolation.
BK300-630VA: 630VA, primary 380V, secondary 110V — high-capacity auxiliary supply for automated production lines.
BK300-1000VA: 1000VA, primary 380V, secondary 110V/220V — industrial press and heavy machine tool control supply.
BK300D-50: 50VA, dual primary, secondary 24V/36V/110V — low-voltage safety circuit supply for hazardous area panels.
BK300D-100: 100VA, dual primary 220V/380V, secondary 110V — standard replacement for legacy BK-100 units.
BK300D-200: 200VA, dual primary, secondary 36V/110V/220V — multi-output for mixed-voltage control architectures.
BK300D-500: 500VA, dual primary 220V/380V, secondary 110V/220V — high-capacity dual-primary variant for export machinery.
BK300-2000VA: 2000VA, primary 380V, secondary 220V — large-format transformer for centralized control room power distribution.

Sourcing Hard-to-Find & Obsolete BK300 Parts

Quality Control for the BK300 Range

Each BK300 unit processed by DriveKNMS undergoes a structured inspection and functional test protocol before dispatch. Primary and secondary winding resistance is measured using a four-wire Kelvin bridge and compared against Delixi factory reference values. Insulation resistance between primary, secondary, and core/frame is tested at 500VDC using a calibrated megohmmeter; minimum acceptable value is 100MΩ. Hi-pot (dielectric withstand) testing is performed at 2000VAC for 60 seconds between primary and secondary windings, per IEC 61558-1 clause 18. No-load voltage output is verified at rated primary input across all secondary taps. Full-load temperature rise is spot-checked on sampled units using a calibrated thermocouple at the winding hotspot. Terminal block torque is verified to manufacturer specification. Units that fail any test parameter are quarantined and not dispatched. Test records are retained for a minimum of 5 years and are available to customers on request.