GEInstallation and Maintenance Manual Bently Nevada™ Asset Condition Monitoring

zener barrier I/O modules. Your application will require 1 Earthing Module per rack 

when internal barrier I/O modules are used. 

2.4 Standard Rack Relay Options 

You can configure the standard (or non-TMR) 3500 rack to have individual relays, 

bussed relays, or a combination of individual and bussed relays. 

2.4.1 Individual Relays 

A rack with individual relays contains 1 or more relay cards for each monitor 

module. You can configure the monitor and relay modules within a 3500 rack in 

many ways. 

Example 1: The application uses 1 relay module 1 monitor module

Table 2-1: 1 Relay Module Used With 1 Monitor Module

Figure 2-4: Typical Standard 3500 Rack with Individual Relays (Full-Size Rack Shown) 

2.4.2 Bussed Relays 

In the Bussed Relays configuration a number of monitor channels share a single 

relay. Use the Rack Configuration Software to define the combination of alarms

that will trigger the relay. Figure 2-5 shows a typical Bussed Relay layout for a

standard 3500 rack. You can [place the monitors and relay modules in any slot as 

long as you link the monitors to the relay module in the Rack Configuration 

Software

3.7.4 Additional Notes 

• Larger scale factors are less susceptible to EMI than smaller scale factors. 

• Larger full-scales are less susceptible to EMI than smaller full-scale. 

• Monitors with narrow bandwidth filter configurations are less susceptible to 

EMI than monitors configured with wide bandwidth. 

• Larger Keyphasor® or hysteresis settings are less susceptible to EMI than 

smaller hysteresis settings. 

• Shorter Alarm delay times may increase monitor susceptibility to transient 

EMI. 

• Environments with higher levels of EMI than tested may cause unpredictable 

monitor readings and may cause system malfunction. 

3.8 Set Rack Jumpers and Switches 

Set the following jumpers and switches before operating the rack: 

• Rack address switch (on the front of the Rack Interface Module) 

• Transducer jumpers on each I/O Module, as required 

• Certain I/O Modules have switches to control their mode of operation. 

Examples include: 

- RIM and Comm Gateway I/O’s that support both RS232 and 

RS422 have a protocol selection switch 

- Overspeed and non-TMR Relay I/O’s have Normally 

Energized/De-energized Relay mode switches 

- Comm Gateway I/O’s that support RS485 have termination 

mode switches 

• Setup phone connection to rack / host (if you use an internal or 

external modem) 

- Phone cable to internal modem in rack