O BWY2 transformer oil temperature indicator is designed for oil-immersed transformer oil temperature detection, temperature control, cooling system control and over-temperature alarm. It is also known as a transformer oil temperature controller, oil temperature indicator or OTI gauge for transformer.
- OTI gauge for oil-immersed transformer oil temperature indication
- Used for transformer oil temperature detection and control
- Adjustable switch contacts for cooling control and over-temperature alarm
- Pt100 output and optional 4-20mA signal output
- Optional digital temperature display with RS485 communication
- Suitable for transformer control cabinets and substation monitoring panels
- Example model: BWY2-804A(T); more BWY2 oil temperature controller models are available on request
BWY2 OTI Gauge for Oil-Immersed Transformer Temperature Monitoring
The BWY2 OTI gauge is used where oil-immersed transformers require local oil temperature indication, cooling control, signal alarm and remote temperature signal output. It helps operators monitor transformer oil temperature and supports safe transformer operation under different load and ambient conditions.
For transformer projects requiring remote display or signal transmission, the BWY2 oil temperature indicator can be configured with optional output and digital temperature display according to the selected model.
What Is a BWY2 Transformer Oil Temperature Indicator?
A BWY2 transformer oil temperature indicator is an OTI gauge used on oil-immersed transformers to detect and control transformer oil temperature, start the cooling system, provide over-temperature alarm output and transmit Pt100 temperature signals.
How the BWY2 Transformer Oil Temperature Controller Works
The BWY2 transformer oil temperature controller is designed based on a compound temperature rise principle. It is used for transformer oil surface temperature detection and control, and it can also be used for temperature detection in other electrical equipment.
The instrument includes adjustable control switches. These switch contacts can be used for cooling system start control and over-temperature alarm. The product can also output a Pt100 platinum resistance signal for remote monitoring or external temperature display.
Key Functions of BWY2 Transformer Oil Temperature Controller
- Oil temperature indication for oil-immersed transformers
- Transformer oil temperature detection and control
- Adjustable control switches for cooling system start control
- Over-temperature alarm output for transformer protection
- Pt100 signal output for remote temperature indication
- Optional 4-20mA output and digital temperature display
- Suitable for transformer temperature monitoring panels and control cabinets
BWY2 Oil Temperature Indicator Model Selection Guide
The BWY2 transformer oil temperature indicator can be selected according to control switch quantity, output signal and special environmental application requirements. The model code helps define the configuration for transformer oil temperature indication, signal output and field environment.

| Model Code Item | Code | Meaning |
|---|---|---|
| Product Series | BWY2 | Transformer oil temperature controller / oil temperature indicator series |
| Scale Code | 80 | Linear scale |
| Control Switch Quantity | Configured by requirement | Switch contact quantity selected according to project requirement |
| Function Code | A | Pt100 output |
| Function Code | J | 4-20mA output, two-wire type |
| Special Environment Code | TH | Suitable for humid tropical areas |
| Special Environment Code | TA | Suitable for dry tropical areas |
| Special Environment Code | T | Suitable for dry and humid tropical areas |
BWY2 Transformer OTI Gauge Technical Specifications
| Product Name | Indicador de temperatura do óleo do transformador |
|---|---|
| Product Series | BWY2 Series |
| Inscrição | Oil-immersed transformer oil temperature indication and control |
| Operating Ambient Temperature | -40°C to +80°C |
| Umidade relativa | ≤95% at 25°C |
| Measuring Range | -20°C to 140°C |
| Precisão | Class 1.5; maximum allowable error at detection point ±2.4°C |
| Switch Contacts | 2-4 adjustable switch contacts |
| Switch Rated Power | AC220V / 5A |
| Temperature Bulb Size | Φ14 × 150 mm |
| Mounting Thread | M27 × 2 mm |
| Capillary Length | According to the last group of digits in the instrument number |
| Protection Grade | IP55 |
BWY2 Oil Temperature Indicator Dimensions and Structure
The BWY2 oil temperature indicator is supplied with mechanical dimension drawings for transformer side-wall installation, thermometer pocket installation and capillary tube routing. Please confirm the final product drawing before transformer body design, panel design or site installation.


| Não. | Component Name | Não. | Component Name |
|---|---|---|---|
| 1 | Sealing Bolt | 6 | Switch Contact Setting Pointer |
| 2 | Mounting Screw | 7 | Temperature Indicating Pointer |
| 3 | Capillary Tube Covered with Stainless-Steel Hose | 8 | Maximum Temperature Recording Pointer |
| 4 | Cable Entry Hole for Φ16 Plastic-Coated Hose Connector | 9 | Maximum Recording Pointer Reset Knob |
| 5 | Temperature Bulb / Temperature Sensor | 10 | Zero Adjustment Knob |
Adjustable Switch Contacts for Transformer Cooling Control and Alarm
The BWY2 transformer oil temperature indicator includes adjustable control switches. These contacts can be used for transformer cooling system control and over-temperature alarm according to transformer operation and protection requirements.
| Switch Contact | Factory Standard Setting | Uso típico |
|---|---|---|
| K1 | 55°C | Configured according to project requirement |
| K2 | 65°C | Configured according to project requirement |
| K3 | 80°C | Configured according to project requirement |
| K4 | 100°C | Configured according to project requirement |
BWY2 OTI Gauge Wiring Diagram Overview
The BWY2 transformer oil temperature controller supports wiring for control switch output and Pt100 platinum resistance signal output according to the selected model and actual product wiring diagram.
| Wiring Item | Função |
|---|---|
| K1 / K2 / K3 / K4 | Control switch output terminals |
| Pt100 Output | Platinum resistance temperature signal output |
Optional Digital Temperature Display for BWY2 Oil Temperature Indicator
The optional digital temperature display can be used together with the BWY2 transformer oil temperature indicator for remote temperature indication, signal transmission and signal control. It is suitable for transformer control panels, remote monitoring cabinets and centralized temperature display applications.
| Acessório | Digital Temperature Display |
|---|---|
| Operating Ambient Temperature | -10°C to +50°C |
| Umidade relativa | ≤85% |
| Fonte de alimentação | AC/DC100–265V, 50–60Hz |
| Output Signal | 4-20mA analog current, RS485 communication |
| Display Type | Digital tube display |
| Precisão | Class 1.0 |
Digital Temperature Display Model Selection for BWY2 OTI Gauge
The optional digital temperature display can be selected according to input signal, working power supply, relay quantity and optional output or communication function. It is used for remote temperature indication, signal transmission and control output in transformer monitoring panels.

| Item de seleção | Code | Meaning |
|---|---|---|
| Product Type | BWX | Digital temperature display |
| Input Signal | A | Pt100 input |
| Input Signal | B | 4-20mA input, two-wire type |
| Working Power Supply | 2 | AC220V |
| Working Power Supply | 5 | AC/DC100–264V |
| Relay Quantity | 0 / 1 / 2 | 0: none; 1: one relay; 2: two relays |
| Optional Function | E | 4-20mA output |
| Optional Function | F | RS485 communication function |
Digital Temperature Display Installation Dimensions
The optional digital temperature display is designed for embedded panel installation. It can be mounted into the reserved opening of the control panel for remote oil temperature indication and signal control.

| Método de instalação | Embedded installation |
|---|---|
| Panel Opening Size | 153 × 77 mm |
| Overall Dimensions | 160 × 80 × 120 mm |
Installation Overview for BWY2 Transformer Oil Temperature Indicator
The BWY2 transformer oil temperature indicator should be installed vertically on the transformer body. The temperature bulb should be inserted into the thermometer pocket filled with transformer oil, and the capillary tube should be properly fixed during installation.
| Installation Item | Requisito |
|---|---|
| Indicator Installation | Vertically fixed on the transformer side wall with 3 M6 bolts |
| Temperature Bulb Installation | Thermometer pocket should be filled with transformer oil before installation |
| Temperature Bulb Position | Temperature bulb should be inserted to the bottom of the thermometer pocket and fixed |
| Capillary Tube Fixing | Capillary tube should be properly fixed every 300mm |
| Extra Capillary Tube | Extra capillary tube should be coiled with a diameter greater than 200mm and fixed properly |
| Wiring Cable Section | Single wire cross-section recommended as 2.5mm² |
Applications of BWY2 Transformer Oil Temperature Indicator
The BWY2 transformer oil temperature indicator is suitable for oil-immersed transformer oil temperature indication, transformer cooling control and over-temperature alarm applications. It can be used in transformer substations, industrial power distribution systems, power plants and transformer control cabinets.
- Transformadores de potência imersos em óleo
- Transformer top oil temperature indication
- Transformer cooling system control
- Transformer over-temperature alarm circuits
- Substation transformer monitoring panels
- Transformer control cabinets
- Remote temperature indication and signal transmission applications
OTI Gauge vs Transformer Winding Temperature Indicator
An OTI gauge is used for transformer oil temperature indication and control. It monitors the transformer oil temperature and supports cooling control and alarm output.
A transformer winding temperature indicator is different. It is used to indicate simulated winding temperature based on transformer top oil temperature and load-current-related thermal simulation. In transformer temperature monitoring projects, OTI and WTI gauges are often selected according to different monitoring purposes.
| Item | BWY2 OTI Gauge | BWR2 WTI Gauge |
|---|---|---|
| Temperature Type | Temperatura do óleo do transformador | Simulated transformer winding temperature |
| Uso típico | Oil temperature indication, cooling control and over-temperature alarm | Winding temperature indication, cooling control, alarm and trip protection |
| Installation Position | Transformer thermometer pocket and side wall | Transformer thermometer pocket and side wall |
Frequently Asked Questions About BWY2 Transformer Oil Temperature Indicator
What is a BWY2 transformer oil temperature indicator?
The BWY2 transformer oil temperature indicator is an OTI gauge used for oil-immersed transformer oil temperature indication, cooling control, over-temperature alarm and Pt100 signal output.
What does OTI mean in transformer temperature monitoring?
OTI means oil temperature indicator. In transformer applications, it is commonly used to indicate transformer oil temperature and provide control signals for cooling and alarm systems.
What is the difference between OTI and WTI in transformer temperature monitoring?
OTI is used for transformer oil temperature indication, while WTI is used for transformer winding temperature indication. OTI focuses on oil temperature, while WTI reflects winding temperature through thermal simulation.
Can the BWY2 oil temperature indicator support remote display?
Yes. The BWY2 transformer oil temperature indicator can be used with an optional digital temperature display for remote indication, signal transmission and control output according to the selected configuration.
What outputs are available for the BWY2 oil temperature controller?
The BWY2 oil temperature controller can provide adjustable switch contacts and Pt100 output. According to model selection, 4-20mA output and digital temperature display options can also be configured.
Where is the temperature bulb installed?
The temperature bulb is inserted into the thermometer pocket on the transformer body. The thermometer pocket should be filled with transformer oil before installation.
Request BWY2 Transformer Oil Temperature Indicator Configuration
For project selection, please provide the transformer type, required output signal, switch contact requirement, remote display requirement and installation environment. INNOFZ can help select a suitable BWY2 oil temperature indicator configuration for your transformer temperature monitoring application.








