0-100°C or 0-120°C measuring ranges
The final implementation follows the confirmed model code, outline drawing and terminal diagram.
Oil Temperature Indicators manufacturer
BWY-802/803 Oil Temperature Controller
A transformer top-oil temperature controller with local indication, Pt100 remote signal and adjustable control contacts.
BWY-802 / BWY-803 Functions for Transformer Temperature Control
Confirm how the selected configuration will indicate temperature, operate contacts and communicate with the remote system.
Pt100 resistance output for remote indication
The final implementation follows the confirmed model code, outline drawing and terminal diagram.
Outdoor IP55 construction with adjustable contacts
The final implementation follows the confirmed model code, outline drawing and terminal diagram.
BWY-802 / BWY-803 Technical Specifications
Use these values for initial comparison, then confirm the selected suffix, options and project interfaces in the current model documents.
| Output signal | Pt100 resistance signal |
|---|---|
| Measuring ranges | 0-100°C or 0-120°C |
| Accuracy | Class 1.5; stated maximum error ±1.8°C for 0-120°C |
| Switching error | ±2°C |
| Switch rating | AC 220 V / 3 A; DC 220 V / 1.5 A |
| Operating ambient | -40°C to +55°C; humidity up to 95% |
| Protection grade | IP55 |
| Temperature bulb | Φ14 mm; insertion depth at least 150 mm |
| Mounting thread | M27 × 2 mm |
| Standard capillary | 5 m |
| Optional remote conversion | 0-5 V, 4-20 mA or RS485 through a compatible display |
BWY-802 / BWY-803 Product Overview
The BWY-802 and BWY-803 controllers measure transformer top-oil temperature and provide a Pt100 resistance signal for remote indication. The mechanical pointer and adjustable contacts support local operating checks and cooling control.
A compatible digital display can convert or retransmit the Pt100 signal as a voltage, current or RS485 interface. The final remote architecture should define who supplies excitation, how cable resistance is handled, and where signal conversion occurs.
How Does the BWY-802 / BWY-803 Temperature Measurement Work?
The bulb, capillary and mechanical sensing element form a sealed temperature system. Oil temperature changes move the pointer and the adjustable microswitch mechanism.
The composite sensing arrangement also provides a Pt100 output. This allows the control room to display the temperature without relying on visual inspection of the local dial.
How to Select the BWY-802 / BWY-803
Choose the 0-100°C or 0-120°C range, confirm contact rating and use, Pt100 wiring, capillary length, mounting dimensions and any remote conversion requirement.
For a BWY replacement, send photographs of the nameplate and terminals together with the existing installation drawing.
BWY-802 / BWY-803 Installation and Commissioning
Insert the bulb into the designated top-oil pocket with the required insertion depth. Do not shorten, kink or sharply bend the capillary.
Verify Pt100 loop resistance and receiving-instrument configuration. Test every switch point using the approved commissioning method.
BWY-802 / BWY-803 Transformer Applications
Distribution transformer oil temperature control
Confirm the measurement point, contact logic, output and mechanical interface against the transformer project documents.
Substation remote oil temperature indication
Confirm the measurement point, contact logic, output and mechanical interface against the transformer project documents.
Cooling system switching
Confirm the measurement point, contact logic, output and mechanical interface against the transformer project documents.
BWY-802 and BWY-803 replacement
Confirm the measurement point, contact logic, output and mechanical interface against the transformer project documents.
Specifications and available options vary by model configuration. Request the current datasheet, outline drawing and terminal diagram before approving an order.
Related BWY-802 / BWY-803 Selection Resources
Compare the Product Category
Review other models for the same transformer temperature measurement and control function.
Compare oil temperature indicatorsPlan Cooling, Alarm and Trip Control
Review how OTI and WTI contacts support transformer cooling stages and protection logic.
Transformer cooling and protection applicationPrepare a Replacement
Compare existing codes, outputs, capillary routing and mounting interfaces before a controller replacement.
Transformer OTI and WTI replacement guideReview Supplier Documents
Check available management-system, conformity and qualification materials for procurement review.
Certification and qualification documentsDirect engineering contact
Request BWY-802 / BWY-803 Selection and Pricing
Email the transformer type, model reference, measuring range, output, switch contacts, capillary length, quantity and destination country. INNO will reply with the applicable configuration details.