Configured for multi-channel thermocouple and RTD signal acquisition in the 3500 Machinery Protection System, the Bently Nevada 285694-02 (3500/61E Temperature Monitor) provides direct physical signal processing for continuous thermal monitoring and alarm logic execution.

Model Identification Matrix

• Part Number: 285694-02

• System Series: 3500/61E

• Functional Class: Temperature Monitoring

Hardware Specifications

Mechanical Monitoring and Signal Integration

The 3500/61E module performs high-resolution analog-to-digital conversion of temperature sensor inputs, requiring strict adherence to signal isolation standards to prevent ground loop interference. Each channel is monitored for open-circuit or short-circuit faults, which update the module's "Not OK" status bit. While this unit focuses on thermal data, it remains integrated within the wider 3500 rack architecture, where cross-talk suppression ensures that high-voltage machinery protection signals do not induce noise into the sensitive low-level thermocouple or RTD measurement loops.

Ordering Information

• 3500/61E Temperature Monitor Module (285694-02)

• Applicable terminal I/O module (Internal or External termination type)

• Configuration software support key (Electronic delivery)

Field Installation Guidelines

• Backplane Integration: Ensure the module is properly keyed and fully seated in the rack slot to engage the backplane communication pins.

• Sensor Wiring: Utilize shielded, twisted-pair cabling for all thermocouple and RTD inputs. Terminate the shield drain wire at the rack ground stud only.

• Field Termination: If using an external termination I/O block, ensure all wiring connections meet the torque specifications provided in the installation manual to prevent intermittent signal loss.

• Grounding: Establish a single-point earth ground for the 3500 rack chassis to comply with electrical safety and EMC requirements.

Frequently Asked Questions

• Does the 285694-02 support hot-swapping?

  Yes, the module is designed for live insertion and extraction within a powered 3500 rack, provided the rack backplane supports active module communication.

• What sensor types are compatible with this module?

  The 3500/61E is configured to support standard thermocouple types (e.g., J, K, E, T) and 100 Ohm platinum RTDs depending on the specific I/O module hardware.

• Can I replace an existing 3500/61 with the 3500/61E?

  Compatibility depends on the rack interface firmware and backplane configuration; verify that the 61E revision meets the system requirements before replacement.

• How is the temperature data transmitted to the host?

  Data is transmitted over the 3500 backplane to the Rack Interface Module (RIM), which then makes the data available via Ethernet or serial protocols.

• Does this module require internal calibration?

  The module is factory-calibrated; however, channel-specific offset adjustments may be performed via the configuration software during commissioning.

• What defines the "Not OK" status?

  A "Not OK" status is triggered by sensor burnout, lead-break detection, or internal hardware diagnostic failure detected by the module's self-test routine.

• Is the 3500/61E limited to a specific number of channels?

  The module provides 6 channels per module; channel configuration is managed through the 3500 Rack Configuration Software.

• How is the cold junction compensation handled?

  The module utilizes a dedicated internal thermistor on the terminal block to perform automated cold junction compensation for thermocouple measurements.