Technical Specifications

FAQ

1. What is the main function of the Bently Nevada 3500/61-01-00 133819-02?

The Bently Nevada 3500/61-01-00 133819-02 is an RTD/TC non-isolated temperature I/O module designed for use with the 3500/61 Temperature Monitor. It receives temperature signals from field-installed RTD sensors and thermocouples, conditions the incoming signals, and transfers the measurement information to the temperature monitoring system. The module provides six temperature input channels, allowing several critical measurement points to be monitored within the same 3500 system. It can be used for bearing temperature, winding temperature, process temperature, housing temperature and other important measurements on turbines, compressors, generators, motors and pumps. The module also supports temperature alarm functions through the associated 3500/61 monitor, making it suitable for continuous condition monitoring and machinery protection applications.

2. Can the 133819-02 use both RTD and thermocouple inputs?

Yes. The 133819-02 is designed to support both RTD and thermocouple temperature sensors. Depending on the application, individual channels can be configured for RTD inputs, thermocouple inputs, or a combination of both sensor types. For example, some channels can be connected to platinum RTDs for bearing temperature measurement while other channels use K-type thermocouples for higher-temperature locations. Each channel must be configured according to the sensor actually connected to it. If the physical sensor type and software configuration do not match, the 3500/61 may calculate an incorrect temperature. During commissioning, technicians should therefore verify the sensor type, wiring, polarity where applicable, and corresponding channel configuration before placing the temperature monitoring system into service.

3. Which thermocouple types are supported by the 133819-02?

The 133819-02 supports E, J, K and T type thermocouple inputs. Each thermocouple type has different electrical characteristics and an applicable temperature range, so the correct type should be selected according to the actual process temperature and installation requirements. K-type thermocouples are commonly used for higher-temperature industrial applications, while T-type thermocouples are often selected for lower-temperature measurements. E and J types can be used for other industrial temperature monitoring requirements. Correct polarity and compatible extension or compensation cable are also important. If the thermocouple type is incorrectly configured or the polarity is reversed, the temperature displayed by the 3500/61 may be inaccurate. The sensor specification and software configuration should therefore always be checked together during installation or replacement.

4. Which RTD sensors can be used with the 133819-02?

The 133819-02 supports several RTD configurations, including 100 Ω platinum, 120 Ω nickel and 10 Ω copper RTDs. The 100 Ω platinum RTD is commonly used for industrial temperature measurement because of its stable resistance-temperature relationship and good repeatability. Different RTD materials and temperature coefficients have different resistance characteristics, so the temperature monitor must be configured for the correct sensor type. Using an incorrect RTD configuration can produce significant temperature measurement errors even when the physical sensor is functioning correctly. When replacing an RTD, technicians should verify the sensor resistance, sensor material, temperature coefficient, wiring arrangement and 3500/61 channel configuration before relying on the measured temperature.

5. What should be checked if one temperature channel shows an abnormal reading?

If only one channel shows an abnormal temperature, troubleshooting should begin with the field sensor and its wiring. For an RTD, check the sensor resistance, wiring continuity and terminal connections for open circuits, short circuits or loose connections. For a thermocouple, verify the sensor type, polarity and extension cable. The internal terminal connections on the 133819-02 should also be inspected for poor contact or damaged wiring. After checking the field circuit, verify that the corresponding 3500/61 channel is configured for the correct sensor type and temperature range. Comparing the abnormal channel with a known-good channel can help determine whether the problem originates from the sensor or the I/O channel. If the field sensor and configuration are confirmed to be correct but the abnormal reading remains, the 133819-02 and associated 3500/61 monitor should then be investigated.

6. What is the difference between the 133819-02 non-isolated I/O module and an isolated temperature I/O module?

The 133819-02 is a non-isolated RTD/TC temperature I/O module, while an isolated temperature I/O configuration provides additional electrical isolation between applicable input circuits. The main advantage of the 133819-02 is its flexibility, because it can handle both RTD and thermocouple inputs and can support mixed sensor configurations across its channels. A non-isolated design can be suitable for many standard industrial temperature monitoring applications where the field wiring and grounding arrangement are properly designed. However, applications involving significant potential differences, severe electrical interference or specific isolation requirements may require a different I/O configuration. When replacing an existing module, technicians should verify the original system design and isolation requirements rather than selecting a replacement based only on the physical appearance or module family.

7. What is the purpose of the recorder outputs on the 133819-02?

The 133819-02 used with the 3500/61 Temperature Monitor provides individual +4–20 mA recorder outputs associated with the temperature channels. These analog outputs can be connected to external control systems, recording instruments, displays or other equipment that requires a continuous temperature signal. The output represents the configured temperature measurement range, so the receiving device must be correctly scaled to interpret the signal. The supported recorder load is 0–600 Ω, meaning the total resistance of the receiving equipment and signal wiring should remain within the specified range. If the temperature shown by the 3500/61 is correct but an external instrument displays an incorrect value, the recorder output wiring, external scaling, receiving device and loop load should be checked.

8. What should be checked after replacing a 133819-02?

After replacing a 133819-02, the complete temperature monitoring circuit should be checked before returning the equipment to normal operation. First confirm that the replacement module has the correct model, part number and RTD/TC non-isolated configuration. Next inspect all six temperature input channels and verify that every field sensor is connected to the correct terminal. The RTD or thermocouple type, polarity, temperature range and channel assignment should then be checked against the approved 3500/61 configuration. After powering the system, observe each temperature channel and confirm that the readings are stable and reasonable for the actual equipment operating condition. The OK, TX/RX and Bypass indicators should also be checked to confirm normal module operation and communication. If external recorder outputs are being used, verify the +4–20 mA signals at the receiving equipment. Finally, check the configured temperature alarms and confirm that the complete temperature monitoring function operates correctly before the machine is returned to normal service.