Moisture sensor and BDV indicator (TFMR/TFTX)
Monitoring the moisture content in the insulating oil and the breakdown voltage
With ETOS®, we have been successfully supporting the automation of transformers for years. New functions are constantly being developed and integrated into ETOS®.
One new function is the continuous monitoring of the insulation strength of the insulating oil and insulating paper in the transformer (TFTX sensor) and the insulation medium in the on-load tap-changer (TFMR sensor). Another important step towards comprehensive transformer monitoring.
Your Advantages at a Glance
-
Continuous monitoring of oil temperature and oil moisture (both relative and absolute)
-
In combination with ETOS®, continuous monitoring of the breakdown voltage is carried out
-
Reducing regular manual oil sampling
-
Customer-specific parameterization of limit values
-
TFTX-Sensor
In combination with the ETOS® "Thermal Monitoring Pro" function, continuous monitoring of the paper moisture is possible
-
TFMR-Sensor
Includes a second PT100 sensor for temperature interlock functions and arctic operation. In combination with MSENSE® VAM, the warranty for the on-load tap-changer is extended to 5 years.
Product Information
Water and moisture are omnipresent in our environment and are essential to life. However, moisture is undesirable in the insulation systems of electrical equipment. Too much moisture in the insulating oil and insulating paper of transformers or in the insulating oil of on-load tap-changers can significantly impair their insulating strength. Water promotes the decomposition reactions of the insulating paper and damages the oil-paper insulation system, which shortens the service life of the transformer and reduces the breakdown voltage of the tap changer oil.
In the past, oil samples had to be taken manually and sent to the laboratory. With our innovative sensors, you can now monitor the oil in your transformers continuously and at no additional effort!
- On the basis of continuous measurements, a trend development can be recognized at an early stage.
- The current status of the oil quality is available at all times.
- Deviations from normal operation can be detected at an early stage.
- Reliable data due to the exclusion of error sources caused by manual activities (e.g. sampling, sample transportation, etc.).
- The measured data is checked for plausibility by comparing it with available online data. This reduces the probability of false alarms.
Moisture sensor and BDV indicator for the on-load tap-changer
| Parameter | Specification |
| Accuracy water activity (aw) 20°C -30°C to +125°C |
±0.02 (0 to 0.9 aw) ±0.03 (0.9 to 1 aw) ±0.05 (0 to 1 aw) |
| Accuracy temperature PT 1000 in Oil (20°C) | ±0.2°C |
| Accuracy temperature PT 100 | acc. to DIN EN 60751, Tolerance class A |
| Measuring range water activity | 0 to 1 aw |
| Measuring range oil temperature | -40°C to +125°C |
| Expected lifetime | > 15 years |
| Water activity response time t90 (20°C) | 10 min. |
| Storage temperature | -40°C to +80 °C |
| Pressure | max. 4 bar (400 kPa) |
| Voltage supply | 24 VDC ± 20% |
| Temperature tesponse time t63 | < 6 s |
| Operating temperature sensor | -30°C to 125°C |
| Measuring frequency | 1 s |
| Digital output | RS 485 (Moisture and PT1000) |
| Protocol | Modbus RTU (Moisture and PT1000) |
| 4…20 mA | PT100, 3-wire |
| Ambient operating temperature | -40°C to +80°C |
| Ambient operating humidity | 5 to 95% rH, non-condensing |
| Altitude | max. 2000 m |
| Vacuum | max. 0.05 mbar (5 Pa) |
| IP class | 66 |
Moisture sensor and BDV indicator for transformers
| Parameter | Specification |
| Accuracy water activity (aw) 0°C to 40°C -40°C to +120°C |
±0.02 (0 to 0.9 aw) ±0.025 (0.9 to 1 aw) ±0.03 (0 to 1 aw) |
| Accuracy temperature PT 1000 in Oil (20°C) | ±0.15°C |
| Resolution | 0.0001 aw |
| Measuring range water activity | 0 to 1 aw |
| Measuring range oil temperature | -40°C to +120°C |
| Expected lifetime | > 15 years |
| Water activity response time t90 (20°C) | 10 min. |
| Storage temperature | -40°C to +80°C |
| Pressure | max. 20 bar (2000 kPa) |
| Voltage supply | 8 - 35 VDC |
| Temperature response time t63 | < 6 s |
| Measuring frequency | 1 s |
| Digital output | RS 485 |
| Protocol | Modbus RTU |
| Ambient operating temperature | -40°C to +80°C |
| Ambient operating humidity | 5 to 95% rH, non-condensing |
| Altitude | max. 2000 m |
| Vacuum | max. 0.05 mbar (5 Pa) |
| IP class | 66 |
Select language
Water and moisture are omnipresent in our environment and are essential to life. However, moisture is undesirable in the insulation systems of electrical equipment. Too much moisture in the insulating oil and insulating paper of transformers or in the insulating oil of on-load tap-changers can significantly impair their insulating strength. Water promotes the decomposition reactions of the insulating paper and damages the oil-paper insulation system, which shortens the service life of the transformer and reduces the breakdown voltage of the tap changer oil.
In the past, oil samples had to be taken manually and sent to the laboratory. With our innovative sensors, you can now monitor the oil in your transformers continuously and at no additional effort!
- On the basis of continuous measurements, a trend development can be recognized at an early stage.
- The current status of the oil quality is available at all times.
- Deviations from normal operation can be detected at an early stage.
- Reliable data due to the exclusion of error sources caused by manual activities (e.g. sampling, sample transportation, etc.).
- The measured data is checked for plausibility by comparing it with available online data. This reduces the probability of false alarms.
Moisture sensor and BDV indicator for the on-load tap-changer
| Parameter | Specification |
| Accuracy water activity (aw) 20°C -30°C to +125°C |
±0.02 (0 to 0.9 aw) ±0.03 (0.9 to 1 aw) ±0.05 (0 to 1 aw) |
| Accuracy temperature PT 1000 in Oil (20°C) | ±0.2°C |
| Accuracy temperature PT 100 | acc. to DIN EN 60751, Tolerance class A |
| Measuring range water activity | 0 to 1 aw |
| Measuring range oil temperature | -40°C to +125°C |
| Expected lifetime | > 15 years |
| Water activity response time t90 (20°C) | 10 min. |
| Storage temperature | -40°C to +80 °C |
| Pressure | max. 4 bar (400 kPa) |
| Voltage supply | 24 VDC ± 20% |
| Temperature tesponse time t63 | < 6 s |
| Operating temperature sensor | -30°C to 125°C |
| Measuring frequency | 1 s |
| Digital output | RS 485 (Moisture and PT1000) |
| Protocol | Modbus RTU (Moisture and PT1000) |
| 4…20 mA | PT100, 3-wire |
| Ambient operating temperature | -40°C to +80°C |
| Ambient operating humidity | 5 to 95% rH, non-condensing |
| Altitude | max. 2000 m |
| Vacuum | max. 0.05 mbar (5 Pa) |
| IP class | 66 |
Moisture sensor and BDV indicator for transformers
| Parameter | Specification |
| Accuracy water activity (aw) 0°C to 40°C -40°C to +120°C |
±0.02 (0 to 0.9 aw) ±0.025 (0.9 to 1 aw) ±0.03 (0 to 1 aw) |
| Accuracy temperature PT 1000 in Oil (20°C) | ±0.15°C |
| Resolution | 0.0001 aw |
| Measuring range water activity | 0 to 1 aw |
| Measuring range oil temperature | -40°C to +120°C |
| Expected lifetime | > 15 years |
| Water activity response time t90 (20°C) | 10 min. |
| Storage temperature | -40°C to +80°C |
| Pressure | max. 20 bar (2000 kPa) |
| Voltage supply | 8 - 35 VDC |
| Temperature response time t63 | < 6 s |
| Measuring frequency | 1 s |
| Digital output | RS 485 |
| Protocol | Modbus RTU |
| Ambient operating temperature | -40°C to +80°C |
| Ambient operating humidity | 5 to 95% rH, non-condensing |
| Altitude | max. 2000 m |
| Vacuum | max. 0.05 mbar (5 Pa) |
| IP class | 66 |
Select language
Reasons for an increasing degree of automation of transformers:
of utility employees will retire in 5 to 10 years
of transformers are older than 30 years
of transformer OEMs are working on a digitalization strategy
