GEInstallation and Maintenance Manual Bently Nevada™ Asset Condition Monitoring

Figure 2-3: 3500 Rack (Full-Size) 

The following sections list the function of each module. Refer to the individual 

operation and maintenance manuals for available options, detailed description, 

operation and maintenance. 

2.3.1 Weatherproof Housing 

The weatherproof housing protects the 3500 rack from adverse environmental 

effects, such as excessive moisture, dirt and grime, and even unclean air. The 

weatherproof housing will not accommodate a Display Unit or VGA Display. 

2.3.2 Rack 

2 types of 3500 racks are available: the full-size 19-inch rack and the compact 12-

inch Mini-rack. Each rack requires you to install the Power Supplies and Rack 

Interface Module (RIM) in specific locations. The full-size version offers 14 

additional rack positions and the Mini-rack offers 7 additional rack positions. You 

may use these positions to install any combination of modules. Both racks 

support Standard (non-redundant) and Triple Modular Redundant (TMR) 

configurations

Application Advisory 

The TMR system will restrict the 

location of certain modules. 

2.3.3 Power Supply 

The Power Supply is a half-height module available in ac and dc versions. You 

can install 1 or 2 power supplies in the rack. Each power supply can power a fully 

loaded rack. When you install 2 power supplies in a rack, the supply in the lower 

slot acts as the primary supply and the supply in the upper slot acts as the 

backup supply. If the primary supply fails, the backup supply will provide power to 

the rack without interrupting rack operation. The 3500 design allows you to 

install any combination of power supply types. 

Overspeed Detection and TMR Monitors require dual power supplies. 

2.3.4 Rack Interface Module 

The Rack Interface Module (RIM) is a full-height module that communicates with

the host (computer), a Bently Nevada™ Communication Processor, and the other 

modules in the rack. The Rack Interface Module also maintains the System Event 

List and the Alarm Event List. You can daisy-chain this module to the Rack 

Interface Modules in other racks and to the Data Acquisition / DDE Server 

Software. The 3500 Monitoring System Computer Hardware and Software Manual

shows how to daisy chain the Rack Interface Modules together. Rack Interface 

Modules are available in Standard, Triple Modular Redundant and Transient Data 

Interface versions. 

2.3.5 Communication Gateway Module 

The Communication Gateway Module is a full-height module that allows external 

devices (such as a DCS or a PLC) to retrieve information from the rack and to set 

up portions of the rack configuration. You can install more than one 

Communication Gateway Module in the same rack. Communication Gateway 

Modules are available for a variety of network protocols. 

2.3.6 Monitor Module 

The Monitor Modules are full-height modules that collect data from a variety of 

transducers. You can install any combination of Monitor Modules in the 3500 

rack. 

2.3.7 Relay Module 

Relay Modules provide relays that you can configure to close or open based on 

channel statuses from other monitors in the 3500 rack. Relay modules are 

available in 4-channel, 16-channel, and 4-channel Triple Modular Redundant 

(TMR) versions. 

The TMR Relay Module is a half-height 4-channel module that operates in a TMR

system. 2 half-height TMR Relay Modules must operate in the same slot. If you 

remove the upper or lower Relay Module or the system declares one of the 

modules as Not OK, then the other Relay Module will control the Relay I/O Module. 

2.3.8 Keyphasor® Module 

The Keyphasor Module is a half-height module that provides power for the 

Keyphasor transducers, conditions the Keyphasor signals, and sends the signals 

to the other modules in the rack. The Keyphasor Module also calculates the rpm 

values sent to the host (computer) and external devices (DCS or PLC) and provides 

buffered Keyphasor outputs. Each Keyphasor Module supports 2 channels. You 

may place up to 2 Keyphasor Modules in a 3500 rack for a maximum of 4 

Keyphasor channels. If you use 2 Keyphasor Modules, you must place them in the 

same full-height slot and the modules will share a common I/O module. 

2.3.9 Display Module 

The 3500 system offers multiple display options. 

The Display Interface Module can display rack data on an LCD-based Interface 

unit or a 3rd-party Modbus® based display unit. 

The VGA Display Module will display rack data on certain touch screen VGA 

Displays. 

The Integrated PC display is a complete rack mount touch screen PC pre-loaded 

with rack configuration software and display utilities. 

2.3.10 Earthing Module 

The Earthing Module is a full-height module that provides a low resistance 

connection (must be less than 1 Ω) from the 3500 rack to the plant’s intrinsically 

safe earth ground. The module operates in conjunction with the 3500 internal