The INNOFZ IB-L201 is a wall-mounted dry type transformer temperature monitoring and control system, purpose-built to protect dry-type transformers from winding overheating. Using microcontroller-based processing combined with PT100 platinum thermistor sensors embedded directly in the transformer winding, the IB-L201 continuously monitors winding temperature rise, automatically controls cooling fan operation, and triggers alarm or trip outputs when temperature exceeds safe operating limits — extending transformer service life and reducing the risk of unplanned outages.
A Complete Temperature Monitoring and Control System, Not Just a Display
The IB-L201 is best understood as a full temperature monitoring and control system rather than a simple temperature monitor. It performs four integrated functions in one wall-mounted enclosure:
- Monitoring — continuously measures winding temperature from up to three PT100 sensors and displays the highest reading on the front-panel digital display
- Control — automatically starts and stops the cooling fan based on real-time winding temperature, with manual override and a periodic fan exerciser function to keep the fan mechanism in working condition
- Protection — drives dedicated relay outputs for over-temperature alarm and trip, allowing the controller to signal or directly intervene before a developing fault becomes a failure
- Diagnostics — includes automatic fault detection, self-inspection, and historical record functions for after-the-fact analysis of temperature events
How PT100-Based Temperature Monitoring Works in This Controller
A platinum thermistor (PT100) sensor is embedded inside the transformer winding during manufacturing or retrofit installation. As winding temperature rises, the sensor's electrical resistance changes in a precise, repeatable relationship with temperature. The IB-L201 reads this resistance value, converts it into an accurate temperature reading, and uses it to drive all of the controller's monitoring, display, fan control, alarm, and trip functions. This sensing approach is the industry-standard method for dry-type transformer winding temperature monitoring and is compliant with the JB/T7631-2005 industry standard for electronic temperature controllers for transformers.
Key Features
- Real-time winding temperature monitoring across up to three measurement points, with maximum-value display
- Automatic and manual cooling fan control, plus periodic fan exerciser to prevent fan seizure during idle periods
- Dedicated relay outputs for over-temperature alarm and trip protection
- Automatic fault detection and controller self-inspection for reliable long-term operation
- Historical temperature record function for maintenance review and post-event analysis
- Adjustable temperature range calibration and switch input judging function
- Clear dual-digit LED display showing channel identifier and live temperature reading
- Status indicator lights for Manual, Fan, Alarm, Trip, Error, and Backup conditions
- Lockable wall-mounted steel enclosure with internal terminal block for clean field wiring
Product Selection: IB-L201 Function Codes
The IB-L201 platform is available in multiple function-code variants, allowing the controller to be matched to specific project communication and monitoring requirements:
| Model | Function |
|---|---|
| IB-L201D | Monitors up to three dry-type transformer windings; displays maximum temperature; built-in fan control and fan exerciser; alarm and trip relay output control; automatic fault detection; historical record function; temperature range calibration; self-inspection; switch input judging function |
| IB-L201E | 4–20mA analog output for integration with SCADA systems |
| IB-L201F | RS485 or RS232 serial communication function |
| IB-L201G | Additional sensor for ambient environment temperature measurement |
| IB-L201I | Additional sensor for silicon steel sheet (core) temperature measurement |
| IB-L201C | Additional PTC150 or PTC130 thermistor for interlocking control |
| IB-L201L | Fan phase-failure detection |
| IB-L201N | Ethernet communication function |
| IB-L201H | Additional environmental humidity measurement |
| IB-L201TH | Three-protection coating (anti-mold, anti-moisture, anti-salt spray) for harsh environments |
| IB-L201P | Profibus communication function |
Model codes can be combined to match project requirements — for example, IB-L201F indicates: L = small wall-mounted temperature control box, 2 = AC220V working power supply (3 = AC380V), F = function code for RS485 communication.
Applications
- Dry-type power transformer winding overheating protection
- Distribution substations requiring automatic fan-cooling control
- Industrial and commercial buildings with dry-type transformer installations
- Projects requiring SCADA integration via 4–20mA, RS485/RS232, Ethernet, or Profibus communication
- Harsh or coastal environments requiring anti-mold, anti-moisture, and anti-salt spray protection
Technical Parameters
| Parameter | Specification |
|---|---|
| Model | IB-L201 series (function codes per selection table above) |
| Temperature Range | -30.0°C to 240.0°C |
| Ambient Operating Temperature | -20°C to +55°C |
| Ambient Humidity | <95% (at 25°C) |
| Working Voltage | AC 220V (+10%, -15%) |
| Working Frequency | 50Hz or 60Hz (±2Hz) |
| Measurement Accuracy | ±1%FS (thermostat level 0.5, sensor class B) |
| Resolution | 0.1°C |
| Fan Output Total Capacity | 5A/250VAC |
| Control Output Capacity | 5A/250VAC; 5A/30VDC (resistive) |
| Power Dissipation | ≤8W |
| External Dimensions | 320 × 260 × 90 mm |
| Installation Method | Wall-mounted |
| Installation Hole Spacing | 280 × 160 mm |
| Production Standard | JB/T7631-2005, Electronic Temperature Controller for Transformers (industry standard) |
| Quality Certification | ISO9001:2008 International Quality Management System Certification |
| EMC Test Standard | IEC61000-4:1995; GB/T17626-2008 |
Installation Dimensions
The IB-L201 wall-mounted enclosure measures 320mm (height) × 260mm (width) × 90mm (depth), with two upper keyhole mounting slots spaced 160mm apart and two lower mounting points spaced 280mm apart vertically, allowing straightforward wall installation using standard mounting hardware.
Customization & Service
INNOFZ manufactures the IB-L201 dry type transformer temperature monitor and controller to order, configuring the function code combination, communication protocol, and protective coating to match each project's environment and integration requirements.
- Custom function code combination selected from the IB-L201 selection table above
- Custom communication protocol: RS485/RS232, 4–20mA, Ethernet, or Profibus
- Special environmental protection coating for coastal, humid, or corrosive installation sites
- OEM/ODM manufacturing and private labeling for qualifying order quantities
- Pre-sales technical consultation and after-sales support, with 12-month warranty
Contact INNOFZ to confirm the right IB-L201 function code combination for your dry-type transformer protection project.
Frequently Asked Questions
What type of sensor does the IB-L201 use to measure winding temperature?
The IB-L201 uses PT100 platinum thermistor sensors embedded directly in the transformer winding. This is the standard sensing method for dry-type transformer winding temperature monitoring and is compliant with the JB/T7631-2005 industry standard.
Can the IB-L201 control the transformer cooling fan automatically?
Yes. The controller automatically starts and stops the cooling fan based on real-time winding temperature, with manual override available and a fan exerciser function that periodically runs the fan to prevent mechanical seizure during long idle periods.
How do I choose the right IB-L201 function code for my project?
Function codes are combined based on the communication and monitoring features required — see the Product Selection table above. For example, if RS485 communication is needed, the model would be IB-L201F; additional functions such as ambient temperature monitoring or humidity measurement can be added with their respective codes.
Is the IB-L201 suitable for installation in humid or coastal environments?
Yes, with the IB-L201TH variant, which adds a three-protection coating against mold, moisture, and salt spray, making it suitable for harsh or coastal installation environments.
What should be done before high-voltage testing of the transformer?
The sensor cable must be removed from the controller before high-voltage testing, and the transformer's power supply must be switched off before connecting or disconnecting the controller, as noted on the unit's front panel warning label.
