Key Technical Specifications

Parameter	Specification
Part Number	167699-02 (1900/65A monitor)
Sensor Inputs	4 channels: 2-/3-wire accelerometers, velocity sensors, or proximity probes
Temperature Inputs	4 channels: Type E, J, K, T thermocouples; 2-/3-wire RTDs
Vibration Processing	24-bit ADC; up to 25 kHz bandwidth; up to 4 variables per channel
Relay Outputs	6 configurable relays with OK/Alert/Danger logic
Analog Outputs	4 configurable 4–20 mA recorder outputs
Buffered Outputs	Dedicated buffered output per sensor input
Communications	Modbus via Ethernet + software-configurable RS232/485
Power Supply	18–36 Vdc standard; optional 110–220 Vac external supply
Configuration	1900 Configuration Software via Ethernet; non-volatile memory
Display	Optional local display/keypad, mountable up to 75 m (250 ft) away
Environment	Operating: -20 to +70 °C; up to 95% RH non-condensing
Mounting	DIN rail or wall/panel mount; optional IP65 enclosure

 

Product Introduction

If you have ever walked into a pump house and found a $40,000 compressor down because nobody noticed a bearing temperature creeping up for three weeks, you understand why the 1900/65A exists. It is not a 3500 rack system. It is not meant for turbine-grade protection. It is a standalone monitor that sits on a DIN rail or panel and watches the machines that usually do not get watched until they fail.The 167699-02 gives you four vibration channels and four temperature channels in one box, with six relays and four 4–20 mA outputs. That is enough to cover a critical pump or fan without buying an entire 3500 frame. The Modbus gateway is the part that actually matters in modern plants — it pushes data straight into the DCS, SCADA, or PLC without a separate gateway box. My only note: this is a legacy 1900-family unit. Do not assume it is a drop-in replacement for a 3500/42M or any other 3500 monitor. It is a different architecture entirely.

Quality SOP & Tech Pitfalls

The Lab Report (SOP)

1. Visual inspection: verify part number 167699-02, model 1900/65A, serial number, and suffix code.
2. Connector and terminal check: inspect sensor, temperature, relay, and analog output terminals for corrosion, bent pins, or loose screws.
3. Power-up test: apply correct supply (18–36 Vdc or specified Vac option) and verify LED status.
4. Channel verification: inject simulated accelerometer/velocity/proximitor signals and confirm measured values.
5. Temperature input check: verify TC/RTD inputs with a calibrated simulator.
6. Relay and 4–20 mA output test: confirm relay trip logic and analog output scaling.
7. Communications test: verify Modbus registers via Ethernet or RS232/485.
8. Configuration backup: upload existing configuration if present; record firmware/software version.
9. Anti-static packaging: seal with photos, test records, and serial data.

The Engineer’s Warning (Pitfalls)

• Wrong family assumption. The 1900/65A is not a 3500 rack module. Some listings incorrectly associate 167699-02 with the 3500 series. If your plant runs 3500/42M or 3500/40M monitors, this unit will not slide into that frame.
• Suffix mismatch. The 1900/65A has suffix codes for power supply, display, communications, and approvals. Replacing a unit with the wrong suffix can leave you without Modbus, without the correct power supply, or without the display you need.
• Sensor type mismatch. Each vibration channel must be configured for the correct sensor type — accelerometer, velocity, or proximity probe. Swapping a proximity probe channel for an accelerometer input without reconfiguration gives garbage readings.
• Lost configuration. If the old monitor dies completely, the configuration lives inside it. Always back up the 1900 configuration file before removal.

 

Installation & Configuration Guide

1. Pre-Installation
   • ⚠️ Obtain work permit and confirm whether relays are wired to trip or alarm.
   • ⚠️ Photograph all terminal wiring, relay assignments, and the existing nameplate/suffix code.
   • Upload and save the current configuration from the existing monitor if it is still accessible.
2. Removal
   • Disconnect power after confirming safe isolation.
   • Label every sensor, temperature, relay, and 4–20 mA wire.
   • Disconnect communication cables last.
3. Installation
   • Verify the replacement suffix matches the original: power supply, display option, Modbus option, and approvals.
   • Mount the monitor on DIN rail or panel per the mechanical drawing.
   • Reconnect wiring exactly as labeled.
   • Reinstall the optional display/keypad if used.
4. Power-On & Testing
   • Apply the correct power supply and verify normal LED indication.
   • Download the saved configuration or rebuild channel assignments.
   • Verify each vibration and temperature channel reading.
   • Test relay outputs and 4–20 mA outputs against expected values.
   • Confirm Modbus communication with the DCS/SCADA/PLC.
   • Return trip circuits to service only after full verification.

Compatible Replacement Models

Compatibility	Model / Option	Notes
✅ Drop-in	Bently Nevada 1900/65A, same suffix	Lowest risk. Match power, display, communications, and approval suffixes.
✅ Functional Replacement	Bently Nevada 1900/65A, different approved suffix	May require configuration reload and wiring verification.
⚠️ System Upgrade	Bently Nevada 3500-series monitor	Requires 3500 frame, new I/O modules, configuration migration, and FAT/SAT. Not a direct swap.
❌ Not Compatible	3500/42M, 3500/40M, 3300-series monitors	Different hardware family, different mounting, different software.

 

Frequently Asked Questions (FAQ)

Q: Is 167699-02 the same as the 1900/65A?
A: Yes. 167699-02 is the Bently Nevada part number for the 1900/65A General Purpose Equipment Monitor.Q: Can I use this in place of a 3500/42M?
A: No. The 1900/65A is a standalone monitor. The 3500/42M is a rack-based 3500-series monitor. They are not interchangeable.Q: Does it support Modbus?
A: Yes. The 1900/65A supports Modbus over Ethernet and RS232/485. Some suffix variants may differ, so confirm the communications option on the nameplate.Q: What sensors can it accept?
A: Each of the four vibration channels can be configured for 2- or 3-wire accelerometers, velocity sensors, or Bently Nevada proximity probes.Q: Can it trip a machine?
A: Yes. It has six configurable relays that can be set to OK, Alert, or Danger states with voting logic. Verify trip wiring before returning the equipment to service.Q: Is this unit still in production?
A: The 1900/65A is a legacy Bently Nevada product. Most available units are new surplus, tested surplus, or refurbished. Confirm condition and configuration before purchase.Q: What warranty should I expect?
A: Reputable suppliers typically offer 12 months on tested units. For machinery protection hardware, insist on a test record rather than an untested “as-is” unit.