9. 3500/50 Tachometer Module

The 3500/50 tachometer module is a two-channel module that receives signals from eddy current sensors or magnetic sensors (unless otherwise noted) to determine shaft speed, rotor acceleration, or rotor direction. It compares these measurements to user-programmable alarm points and issues an alarm when the alarm point is exceeded. The 3500/50 tachometer module can be programmed using the 3500 frame configuration software and can be configured into four different types:

1. Speed monitoring, setpoint alarm, and speed band alarm

2. Speed monitoring, setpoint alarm, and zero speed indication

3. Speed monitoring, setpoint alarm, and rotor acceleration alarm

4. Speed monitoring, setpoint alarm, and reverse indication

The 3500/50 can be configured to provide key phase signals to the 3500 frame backplane for use by other monitors, thus eliminating the need for a separate key phase module within the frame. The 3500/50 also features a peak hold function; it can store the highest speed, highest reversal speed, or number of reversals ever achieved by the machine (depending on the selected channel type). These peaks can be reset by the user.

Application Notes
• Bentley Nevada tachometer modules are not used alone or as a component in speed control or overspeed protection systems.

• Bentley Nevada tachometer modules do not provide protection redundancy or responsive speed for speed control or overspeed protection systems.

• Analog proportional outputs are used only for data collection, chart logging, or display. Additionally, the speed warning setpoint is for notification purposes only.

• Magnetic sensors do not use the reversal option because these sensors do not provide a clear edge to the detection circuit at low speeds, which would cause false reversal indications.

• Magnetic sensors are not recommended for the zero-speed option because these sensors do not provide a clear edge to the detection circuit at low speeds.

Each tachometer module receives signals from one or two eddy current sensors or magnetic sensors, with a signal range of +10.0V to -24.0V. Signals outside this range are internally restricted within the module. Alarm Point Settings: Level 1 alarms can be set by the tachometer for each measured value. In addition, Level 2 alarms can be set by any two values from the tachometer measurements. All alarm points are configured by software. Alarm points are adjustable, typically set within the range of 0% to 100% of full scale. Alarm delays can be programmed by software and set as follows:

Alarm 1: From 1 to 60 seconds, adjustment interval is 1 second;

Alarm 2: From 1 to 60 seconds, adjustment interval is 0.1 seconds. The meanings of the front panel LEDs are similar to those of the modules mentioned earlier.

The following diagram shows the front view of the tachometer module and the rear view of several I/O modules.

1.Status LEDs--133388-02
2.Buffered transducer outputs
3.I/O Module, Internal Terminations--133442-01
4.I/O Module, External Terminations--133434-01
5.I/O Module, TMR, External Terminations--133450-01
6.I/O Module, Internal Barrier, Internal Terminations--136703-01

10. 3500/53 Overspeed Detection Module
The Bentley Nevada 3500 Series Mechanical Inspection System's electronic overspeed detection system is a highly reliable, fast-response redundant tachometer system specifically designed for overspeed protection of machinery. The 3500/53 module can be used to form a 2-to-2 or 3-to-2 (recommended) voting system. The 3500 frame for installing the overspeed detection system requires a redundant power supply.

Each overspeed detection module receives a signal from an eddy current sensor or magnetic sensor, with an input signal range of +10.0V to -24.0V. Signals outside this range are limited within the module. Suitable for Bentley Nevada 3300 8mm eddy current sensor, 3300 16mm High Temperature Eddy Current Sensor (HTPS), 7200 5mm, 8mm, 11mm, and 14mm eddy current sensors, 3300 RAM eddy current sensor, or magnetic sensor.

Front Panel LED (Light Emitting Diode) Meanings:

OK LED: Indicates the 3500/53 module is working normally.

TX/RX (Transmit/Receive) LED: Indicates the 3500/53 module is communicating with other modules within the 3500 frame.

Bypass LED: Indicates the 3500/53 module is in bypass mode.

Test Mode LED: Indicates the 3500/53 module is in test mode.

Alarm LED: Indicates an alarm condition has occurred and the associated relay has actuated. Sensor Buffered Output: Each module has a coaxial connector on the front for buffered output. Each connector is short-circuit and electrostatic discharge protected. For speed, alarm levels (setpoints) can be set below or above. Additionally, a danger (overspeed) setpoint can be set for speed. All alarm setpoints are configured by software. Alarm points are adjustable and typically adjustable within the 0–100% full scale range. Alarm time delay: Less than 30ms at frequencies above 300 Hz. For other functions, please refer to the 3500/53 Overspeed Protection System Operation and Maintenance Manual.

1) Main Module, front view.--133388-01
2) Status LEDs
3) Buffered transducer output. Provides an unfiltered output for the transducer. The output is short-circuit protected.
4) I/O Module, rear view.--133396-01

11.3500/32M 4-Channel Relay Module

The 4-Channel Relay Module is a full-height module that provides four relay outputs. Any number of 4-Channel Relay Modules can be placed in any of the slots to the right of the Transient Data Interface Module. Each output of the 4-Channel Relay Module can be independently programmed to perform voting logic.

Each relay utilized on the 4-Channel Relay Module includes Alarm Drive Logic.

Programming for the Alarm Drive Logic uses AND and OR logic, and can use alarming inputs (Alert and Danger statuses), Not- OK, or individual PPLs from any monitor channel or any combination of monitor channels in the rack. You can program this Alarm Drive to meet your application needs using the 3500 Rack Configuration Software.

Front Panel LED Meanings:

OK LED (Light Emitting Diode): Flashes when the module is working normally.

TX/RX LED: Used for transmission and reception; flashes when communication between this module and other modules in the frame is normal.

H ALARM LED: Flashes when the relay channel is in alarm state.

Relay Type: Two single-pole double-throw (SPDT) relays connected together to form a double-pole double-throw (DPDT) relay.

Sealing: Epoxy resin sealed; contact life 100,000 cycles @ 5A, 24Vdc or 120Vdc.

Operating Mode: Each channel can be selected by a switch to be normally de-energized or normally energized.

1.Relay module--149986-02
2.I/O module--125720-01
3.Status LEDs
4.Relay channel LEDs
5.Relay contacts
6.Relay mode selection switch