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Control transformers

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 Enhancing Reliability & Efficiency with Advanced Thermal Management and Electrical Solutions

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Product Overview

Double insulation and overload protection, stable power supply for control circuit.

  • Dedicated to control circuit: Optimized voltage control technology, output stability improved by 20%, ensuring efficient operation of the control circuit.
  • Overload protection function: Built-in overload protection to avoid equipment damage caused by overcurrent.
  • Double insulation design: Enhanced insulation performance, improved safety, suitable for various industrial scenarios.

 

 

Key Advantages

● Exceptional Voltage Stability: Precision CRGO silicon-steel cores and tightly-wound copper coils keep secondary voltage within ±2 % under full-load and transient inrush conditions.
● Ultra-Low No-Load Losses: Optimized laminations reduce idle current draw and heat generation, increasing overall system efficiency.
● Superior Thermal Management: Class B or F insulation combined with vacuum-pressure-impregnated windings and ventilated housings limit temperature rise to well below rated thresholds.
● Flexible Mounting Styles: Choose chassis-mount open-frame (JSG/SG) for easy access, slim DIN-rail clip (SGB/JBK3/JBK5) for space-constrained panels, or rugged panel bracket (JBK6/JBK7) for heavy-load installations.
● Built-In Tap Adjustments: Primary tap options (±5 × 2.5 %) allow on-site fine-tuning of input voltage without rewinding.
● ISO-Certified Quality: All units undergo 100 % factory testing—insulation resistance, turns-ratio verification, and load-endurance checks—to guarantee long-term reliability.

Product Catagories

JBK2 Control transformers

JBK2 Series: A cost-effective solution for basic control circuit applications. providing dependable performance with minimal maintenance requirements.

wdt_ID wdt_created_by wdt_created_at wdt_last_edited_by wdt_last_edited_at Model L (mm) W (mm) H (mm) A (mm) B (mm) KF F
1 Kiva 09/07/2025 05:20 AM Kiva 09/07/2025 05:20 AM JBK2-63VA 84 94 92 64 ± 0.2 62 ± 0.2 46 15
2 Kiva 09/07/2025 05:20 AM Kiva 09/07/2025 05:20 AM JBK2-100VA 96 105 105 84 ± 0.2 87 ± 0.2 58 15
3 Kiva 09/07/2025 05:20 AM Kiva 09/07/2025 05:20 AM JBK2-160VA 96 110 105 84 ± 0.2 85 ± 0.2 58 15
4 Kiva 09/07/2025 05:20 AM Kiva 09/07/2025 05:20 AM JBK2-250VA 120 100 122 90 ± 0.2 85 ± 0.2 58 15
5 Kiva 09/07/2025 05:20 AM Kiva 09/07/2025 05:20 AM JBK2-400VA 120 115 122 90 ± 0.2 96 ± 0.2 7 2
6 Kiva 09/07/2025 05:20 AM Kiva 09/07/2025 05:20 AM JBK2-500VA 150 110 145 122 ± 0.2 90 ± 0.2 7 2
7 Kiva 09/07/2025 05:20 AM Kiva 09/07/2025 05:20 AM JBK2-630VA 150 128 145 122 ± 0.2 105 ± 0.2 7 2
8 Kiva 09/07/2025 05:20 AM Kiva 09/07/2025 05:20 AM JBK2-800VA 168 125 155 138 ± 0.2 105 ± 0.2 9 2
9 Kiva 09/07/2025 05:20 AM Kiva 09/07/2025 05:20 AM JBK2-1KVA 168 125 155 138 ± 0.2 105 ± 0.2 9 2
10 Kiva 09/07/2025 05:20 AM Kiva 09/07/2025 05:20 AM JBK2-1.6KVA 168 138 155 138 ± 0.3 116 ± 0.5 10 3
Model L (mm) W (mm) H (mm) A (mm) B (mm) KF F

JBK3 Control transformers

ldeal for standard applications, offering reliable power and durability for general industrial use.

wdt_ID wdt_created_by wdt_created_at wdt_last_edited_by wdt_last_edited_at Model B max D max E max A C Hole diameter K F max
1 Kiva 09/07/2025 05:27 AM Kiva 09/07/2025 05:27 AM JBK3-40、63 78 72 89 56±0.4 51±2 48 2
2 Kiva 09/07/2025 05:27 AM Kiva 09/07/2025 05:27 AM JBK3-100 85 85 94 64±0.4 66±2 48 2
3 Kiva 09/07/2025 05:27 AM Kiva 09/07/2025 05:27 AM JBK3-160 96 91 109 84±0.4 73±2 58 2
4 Kiva 09/07/2025 05:27 AM Kiva 09/07/2025 05:27 AM JBK3-250 95 105 109 84±0.4 87±2 58 2
5 Kiva 09/07/2025 05:27 AM Kiva 09/07/2025 05:27 AM JBK3-400 120 109 123 90±0.4 90±2 7 25
6 Kiva 09/07/2025 05:27 AM Kiva 09/07/2025 05:27 AM JBK3-630 150 112 150 122±0.5 77±2 6 25
7 Kiva 09/07/2025 05:27 AM Kiva 09/07/2025 05:27 AM JBK3-1000 160 195 151 126±2 152±2 7 3
8 Kiva 09/07/2025 05:27 AM Kiva 09/07/2025 05:27 AM JBK3-1600 184 220 163 140±2 176±2 7 3
9 Kiva 09/07/2025 05:27 AM Kiva 09/07/2025 05:27 AM JBK3-2500 200 250 171 172±2 200±2 7 4
Model B max D max E max A C Hole diameter K F max

JBK5 Control transformers

JBK5 Series: Desiqned for advanced industrial environments, with improved aesthetics, safety features, and voltage stability for more demanding conditions.

wdt_ID wdt_created_by wdt_created_at wdt_last_edited_by wdt_last_edited_at Model Order number B max D max E max A C Hole diameter K F max Remarks
1 Kiva 09/07/2025 07:29 AM Kiva 09/07/2025 07:29 AM JBK5-40. 63 4011-01-01 78 72 90 56±0.15 46±0.125 46 15
2 Kiva 09/07/2025 07:29 AM Kiva 09/07/2025 07:29 AM JBK5-100 4011-01-03 84 75 96 64±0.15 62±0.15 46 15
3 Kiva 09/07/2025 07:29 AM Kiva 09/07/2025 07:29 AM JBK5-160 4011-01-04 96 92 105 84±0.175 73.5±0.15 55 15
4 Kiva 09/07/2025 07:29 AM Kiva 09/07/2025 07:29 AM JBK5-250 4011-01-05 96 100 104 84±0.175 85±0.175 58 15
5 Kiva 09/07/2025 07:29 AM Kiva 09/07/2025 07:29 AM JBK5-400 4011-01-06 120 100 122 90±0.175 8510.175 58 2
6 Kiva 09/07/2025 07:29 AM Kiva 09/07/2025 07:29 AM JBK5-500 120 110 122 90±0.175 96±0.175 58 2
7 Kiva 09/07/2025 07:29 AM Kiva 09/07/2025 07:29 AM JBK5-630 4011-01-07 150 no 140 122±0.2 9010.175 7 2
8 Kiva 09/07/2025 07:29 AM Kiva 09/07/2025 07:29 AM JBK5-800 4011-01-08 150 128 142 122±0.2 10510.2 7 2
9 Kiva 09/07/2025 07:29 AM Kiva 09/07/2025 07:29 AM JBK5-1000 150 190 142 126±0.2 15210.2 7 3 Horizontal
10 Kiva 09/07/2025 07:29 AM Kiva 09/07/2025 07:29 AM JBK5-1000 168 125 155 138±0.2 10510.2 9 2 Vertical
Model Order number B max D max E max A C Hole diameter K F max Remarks

JBK6 Control transformers

JBK6 Series: Built for harsh environments, featuring corrosion resistanceand protection against extreme conditions like humidity, coastal exposureor desert climates.

wdt_ID wdt_created_by wdt_created_at wdt_last_edited_by wdt_last_edited_at Model Order number B max D max E max A C Hole diameter K F max Remarks
2 Kiva 09/07/2025 07:29 AM Kiva 09/07/2025 07:29 AM JBK6-40. 63 4013.001/2 78 72 90 56±0.15 46±0.125 4.6 1.5
3 Kiva 09/07/2025 07:29 AM Kiva 09/07/2025 07:29 AM JJBK6-100 4013.003 85 75 96 64±0.15 62±0.15 4.6 1.5
4 Kiva 09/07/2025 07:29 AM Kiva 09/07/2025 07:29 AM JBK6-160 4013.004 96 92 105 84±0.175 73.5±0.15 5.5 1.5
5 Kiva 09/07/2025 07:29 AM Kiva 09/07/2025 07:29 AM JBK6-250 4013.005 96 100 104 84±0.175 85±0.175 5.8 1.5
6 Kiva 09/07/2025 07:29 AM Kiva 09/07/2025 07:29 AM JBK6-400 4013.006 120 100 122 90±0.175 85±0.175 5.8 2
7 Kiva 09/07/2025 07:29 AM Kiva 09/07/2025 07:29 AM JBK6-500 4013.007 120 110 122 90±0.175 96±0.175 5.8 2
8 Kiva 09/07/2025 07:29 AM Kiva 09/07/2025 07:29 AM JBK6-630 4013.008 150 110 140 122±0.2 90±0.175 7 2
9 Kiva 09/07/2025 07:29 AM Kiva 09/07/2025 07:29 AM JBK6-800 4013.009 150 128 142 122±0.2 105±0.2 7 2
10 Kiva 09/07/2025 07:29 AM Kiva 09/07/2025 07:29 AM JBK6-1000 4013.01 150 190 142 126±0.2 152±0.2 7 3 Horizontal
11 Kiva 09/07/2025 07:29 AM Kiva 09/07/2025 07:29 AM JBK6-1000 4013.011 168 125 155 138±0.2 105±0.2 9 2 Vertical
Model Order number B max D max E max A C Hole diameter K F max Remarks

JBK7 Control transformers

JBK7 Series: The premium option for critical and high-performance applications, delivering low energy loss, high efficiency, and superiorreliabilityin extreme temperatures.

wdt_ID wdt_created_by wdt_created_at wdt_last_edited_by wdt_last_edited_at Model Order number B max D max E max A C Hole diameter K F max Remarks
2 Kiva 09/07/2025 07:29 AM Kiva 09/07/2025 07:29 AM JBK7-40. 63 4014.001/2 78 72 90 56±0.5 46±0.5 4.6 1.5
3 Kiva 09/07/2025 07:29 AM Kiva 09/07/2025 07:29 AM JBK7-100 4014.003 84 75 96 64±0.5 62±0.5 4.6 1.5
4 Kiva 09/07/2025 07:29 AM Kiva 09/07/2025 07:29 AM JBK7-160 4014.004 96 92 105 84±0.5 73.5±0.5 5.5 1.5
5 Kiva 09/07/2025 07:29 AM Kiva 09/07/2025 07:29 AM JBK7-250 4014.005 96 100 104 84±0.5 85±0.5 5.8 1.5
6 Kiva 09/07/2025 07:29 AM Kiva 09/07/2025 07:29 AM JBK7-300 4014.006 120 112 105 84±0.5 85±0.5 5.8 2
7 Kiva 09/07/2025 07:29 AM Kiva 09/07/2025 07:29 AM JBK7-400 4014.007 150 100 122 90±0.5 85±0.5 5.8 2
8 Kiva 09/07/2025 07:29 AM Kiva 09/07/2025 07:29 AM JBK7-630 4014.008 150 110 140 122±0.5 90±0.5 7 2
9 Kiva 09/07/2025 07:29 AM Kiva 09/07/2025 07:29 AM JBK7-800 4014.009 150 128 142 122±0.5 105±0.5 7 2
10 Kiva 09/07/2025 07:29 AM Kiva 09/07/2025 07:29 AM JBK7-1000 4014.01 150 205 142 126±0.2 152±0.2 7x12 3 Horizontal
11 Kiva 09/07/2025 07:29 AM Kiva 09/07/2025 07:29 AM JBK7-1000 4014.011 168 138 155 138±0.5 105±0.5 9x15 2 Vertical
Model Order number B max D max E max A C Hole diameter K F max Remarks

Applications

  • PLC and relay control cabinet
    Provide stable and isolated control power for programmable logic controllers (PLCs), intermediate relays and small automation modules.
  • Motor control center (MCC)
    Supply power to the control coils of contactors, soft starters and inverters to ensure voltage stability under frequent start-stop and heavy load conditions.
  • Building automation and HVAC systems
    Drive thermostats, damper actuators, sensors and lighting control devices to achieve safe isolation and power supply for subsystems such as HVAC, fire alarms, and intelligent lighting.
  • Safety and alarm systems
    Provide isolated power to emergency stop circuits, grating protection devices, alarm buzzers, and access control systems to ensure reliable power failure and signal transmission in the event of a fault.
  • Machine tools and machining centers
    Provide low-voltage control circuit power for CNC systems (CNC), servo drives, and tool magazines, etc., to support voltage anti-interference capabilities during high-speed cutting and frequent tool changes.
  • Power distribution and branch cabinets
    In the power distribution room or sub-distribution cabinet, power is supplied to measuring instruments, energy meters, transmitters and auxiliary relays to achieve accurate monitoring of power, energy consumption and process variables.
  • Renewable energy inverter and energy storage system
    Provide isolated DC or AC control power to the inverter control board, PV/wind power monitoring terminal and battery management system (BMS) to ensure safe operation of the system.
  • Rail transportation and automated logistics
    Provide isolated anti-interference power for train door control, signal machine, track monitoring and automated three-dimensional storage system to meet high reliability and vibration resistance requirements.
  • Petrochemical and process industry
    In continuous processes such as refining, chemical or food and pharmaceutical, power is supplied to valve positioners, flow/pressure transmitters and emergency cut-off circuits to ensure process safety and stability.
  • Industrial robots and assembly lines
    Power is supplied to robot control cabinets, visual inspection equipment and end effectors to support high-precision, high-speed motion control and automated assembly tasks.

Basic Knowledge

  • Isolation vs. Step-Down: Control transformers isolate sensitive circuits from mains disturbances while reducing voltage to safe control-circuit levels.
  • Open-Frame vs. Enclosed: Open-frame units offer best heat dissipation but require clean cabinet environments; enclosed units provide basic dust protection.

  • DIN-Rail Mount Benefits: Snap-in installation speeds up assembly and simplifies service without opening the panel.

    1. Core & Lamination Secrets

    High-quality control transformers use cold-rolled grain-oriented silicon steel laminations to minimize hysteresis losses. Budget units often skimp on lamination thickness, increasing no-load losses and heat build-up. Look for ones rated with Class B or F insulation that specify maximum temperature rise (e.g., 80 °C) under continuous duty.

    2. Inrush Current & Overload Tolerance

    A true control transformer design incorporates a dual-tapped primary or soft-start winding to limit magnetizing inrush. Without it, breakers nuisance-trip at power-up. Also, the transformer’s VA rating should include a 115 % continuous overload margin to handle short control-relay pick-up currents without overheating.

    3. Isolation vs. Control Characteristics

    Unlike isolation transformers, control transformers are optimized for low-voltage control circuits, not for “clean” power. They tolerate DC offsets and low-frequency fluctuations better and often include built-in electrostatic shields between windings to reduce EMI transmitted into PLCs and sensitive electronics.

    4. Mounting & Vibration Hardening

    Industrial panels mounted on mobile platforms (cranes, vehicles) demand anti-vibration bushings on transformer feet. Rigid mounting causes core-coil fatigue under harmonic loads, leading to buzzing and eventual failure. Spring-isolated brackets extend service life in high-vibration settings.

    5. Environmental Durability

    In dusty or corrosive environments, specify sealed-frame transformers with Class 1 enamel coatings on windings. In tropical climates, look for conformally coated coils rated for 95 % relative humidity—standard coils can suffer insulation breakdown in under two years.

    6. Vector Group & Phase Considerations

    For three-phase control transformers, vector group (“Y–Δ,” “Δ–Y”) selection affects ground-fault detection and available neutral. A “Δ–Y” unit provides a neutral for control circuits, but introduces a 30° phase shift—critical when syncing with upstream protective relays.

    7. Maintenance & Lifecycle Insights

    Unlike mains transformers, control transformers run hot and switch loads frequently. Periodic infrared thermography catches hot-spot winding issues early. Investing in a spare coil form—rather than a whole new unit—can halve repair turnaround when field-wound units require rewind.

Why Choose Leipole?

As a professional buyer, do you face these challenges?

❌ Delivery delays – affecting project progress and production line stability

❌ Poor technical adaptability – standard products cannot meet complex working conditions

❌ High hidden costs – frequent maintenance, excessive energy consumption, slow after-sales response

❌ Compliance risks – lack of international certification leads to customs clearance and warranty disputes

Leipole is proud to offer one-stop solution:

💎 Global layout, zero delivery delays

  • R&D and sales headquarter led by the team in Singapore – cutting-edge cooling technology iteration to ensure product leadership
  • Manufacturing base in Shanghai, China – ISO 9001 & ISO14001 certified, cost optimization + high quality control standards
  • Localized warehousing in 24 countries – spot shipments from the EU, America, and Southeast Asia, urgent orders arrive within 3 days

🔧 Deep customization capabilities to solve complex needs

  • OEM/ODM full-case support – from cooling structure design to branding customization, 100+ successful cases (Industrial Automation/ New Energy Industry/Data Centers)
  • Working condition simulation test – Free simulation of air volume, high temperature, high humidity and vibration environment to ensure 100% adaptability of the solution

🌍 Worry-free compliance, global access

  • Authoritative certification – CE, UL, RoHS, REACH full coverage, hassel-free customs clearance in Europe, America and Southeast Asia

🚀 Cost optimization throughout the entire life cycle

  • Energy consumption reduced by 30% – patented airflow design, saving 30% in electricity bills per year compared to peer product
  • 1-year warranty – redundant design of key components, failure rate <0.2%
  • 7×24 localized service – 50+ national technical teams, 4-hour response, direct supply of spare parts.

Customization Process

Accurate Demand Analysis

Professional engineers deeply understand your equipment parameters, application environment, and special requirements.

Customized Technical Solutions

R&D teams develop optimal heat dissipation solutions based on your needs, including airflow calculations and installation planning.

 Sample Testing and Validation

Provide samples for real-environment testing, collect data feedback, and ensure solution effectiveness.

Mass Production

After confirming the solution, production follows strict ISO9001 quality management systems to ensure batch stability.

FAQ

Q1: How do I select the right VA rating?
Add the VA of all control loads (relays, coils, PLC inputs) plus 25 % margin; choose the next standard size.
Q2: Can I adjust taps under power?
Primary taps are selectable only when de-energized; secondary rewiring must be done by qualified personnel.
Q3: What ambient temperature range is supported?
Standard models operate from –20 °C to +60 °C; ensure adequate ventilation for open-frame units.
Q4: Are replacement parts available?
Yes—covers, mounting brackets, and terminal blocks can be ordered separately.

🔹When should I choose an industrial control transformer for machine tools?

💡Use an industrial control transformer when you need reliable, low-voltage power for machine tool control circuits, ensuring stable operation under high inrush and frequent switching.

🔹How does a control transformer 110V to 24V step-down improve safety?

💡A 110V to 24V step-down control transformer isolates the high-voltage mains from control wiring, reducing shock hazards and allowing safer interface with relays and PLC inputs.

🔹Why use an isolation control transformer for PLCs?

💡An isolation control transformer prevents ground loops and noise from propagating into sensitive PLC power supplies, enhancing signal integrity and reducing unexpected resets.

🔹What are the benefits of a toroidal control transformer low noise design?

💡A toroidal control transformer offers lower magnetic stray fields and audible hum compared to EI-core designs, making it ideal for quiet environments or noise-sensitive control rooms.

🔹Where do sealed control transformers for harsh environments excel?

💡Sealed control transformers with epoxy-filled or gasketed enclosures withstand dust, moisture, and corrosive atmospheres, perfect for food, chemical, or outdoor installations.

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