BENTLY 125840-02 Low Voltage AC Power Input Modules

Transient Data Interface (TDI)

The TDI is the 3500 Rack’s primary interface to the configuration, display, and condition monitoring

software. Each rack requires one TDI, located in the rack slot immediately adjacent to the power supply slot.

The TDI supports a proprietary protocol used by the 3500 Configuration Software to configure the rack and

the 3500 Operator Display Software to retrieve rack data and statuses.

The TDI also provides a direct interface with System 1* Condition Monitoring and Diagnostic software

without the need for an external communications processor.

The Rack OK relay is located within the TDI’s I/O module. It is driven by NOT OK conditions within the

TDI itself and within other modules in the rack.

the power supply’s front panel.

The TDI supports self-monitoring functions both for itself and for the rack, in addition to those provided by

the individual monitor, relay, communications, and other modules. While the TDI provides certain

functions common to the entire rack, it is not part of the critical monitoring path and its machinery

protection functions.

The TDI has four front-panel LEDs that provide the following indications:

Power Supply

The 3500/15 Power Supply can be ordered for ac or dc input power, providing compatibility with voltage

sources worldwide. Line noise filters are standard. The 3500 Rack can operate from a single supply, or

dual supplies can be used to provide redundancy for situations that cannot tolerate power interruption.

Dual supplies reside in the upper and lower positions of the left-most rack slot. Redundant supplies

can use separate voltage sources. For example, the primary (lower) supply can operate with 120 Vac

power while the backup (upper) supply can be powered from an uninterruptible 24 Vdc source.

Each supply can individually provide power to the entire rack and its modules. When redundant

supplies are used, the lower supply acts as primary power for the rack while the upper supply acts as a

backup, ready to instantly and automatically operate as the primary rack supply without interrupting

rack functions should the primary supply fail.

The 3500/15 Power Supply module has self-monitoring functions that allow it to determine if all its

output voltages are within specifications. The module annunciates this via a green Supply OK LED on

the power supply’s front panel.

System components are described in more detail in the following section and in their individual datasheets.

The Bently Nevada Seismic Probe Velocity Sensor System is designed to measure absolute vibration (relative to free space) of a bearing housing, enclosure, or structure.

The two-wire system consists of a transducer and appropriate cable.

The Seismoprobe series of velocity sensors is a two-wire design using moving coil technology.

It provides a voltage output proportional to the vibration velocity of the sensor.

Moving coil sensors are less sensitive to shock or pulse excitation than solid state velocity sensors.

Solid-state velocity sensors are themselves accelerometers with embedded integrated electronics.

Moving coil sensors are less sensitive to shocks or pulsed excitation and are a good choice for some applications.

Portable measurement applications are facilitated by the fact that no external power supply is required.

System Components 

This section describes the individual components that make up a complete 3500 system. 

Instrument Rack The standard 3500 Rack is available in 19” EIA rail-mount, panel-cutout-mount, and bulkhead-mount versions.

The rack provides slots for two Power Supplies and a TDI in the left-most rack positions that are reserved exclusively for these modules. 

The remaining 14 slots in the rack can accommodate any combination of monitor, display, relay, Keyphasor module, 

and communication gateway modules. 

All modules plug into the rack’s backplane and consist of a main module and an associated I/O module. 

The I/O module installs at the rear of the rack for panel-mount systems, and above the main module for bulkhead-mount systems. 

Standard rack depth is 349 mm (13.75 inches), while bulkhead mount rack depth is 267 mm (10.5 inches). 

NEMA 4 and 4X weatherproof housings are available when required for environmental protection or when purge air is used.

Other advantageous products on sale are listed below: