Bently Nevada Asset Condition Monitoring 3300/03 System Monitor

MONITOR FUNCTIONS

SYSTEM POWER-UP INHIBIT

The System Monitor provides a Power-up Inhibit function. This function allows each monitor to

inhibit its alarms during power-up or whenever a system supply voltage falls below its operating

level. After power-up, the inhibit function remains active for approximately 2 seconds.

RACK INHIBIT

When activated by a external contact closure this function places all monitors in bypass, disables

all alarms, zero scales all outputs, and de-energizes the system OK relay. The connections for this

function are located on the power input module (PIM) at the rear of the rack.

SUPPLY VOLTAGES OK

Seven LEDs located behind the front panel of the System Monitor are ON to indicate the voltage

supplies are functioning. The voltage supplies are +VRH, +VRL, +7.5V, +5V, REF, -7.5V, and -VT.

There is a green LED (SUPPLIES OK) on the front panel of the System Monitor. When this LED is on

all of the voltage supplies are functional.

SYSTEM RESET

The System Monitor provides the ability to cause a System Reset. Closing external contacts

through terminals on the PIM or pressing the RESET switch on the front panel will cause a System

Reset.

TRIP MULTIPLY

The most common use of this function is to prevent unwanted monitor alarms during certain

conditions of machine operation. In the operation of some machinery, it is impossible to avoid

some periods of "higher than normal" vibration. Examples include startup and coastdown,

especially if the operating speed is above rotor system balance resonances ("critical speeds"),

structural and other resonances, and changes in machine load or other operating conditions.

The Trip Multiply function causes the monitor alarm setpoints (both Alert and Danger) to increase

by a fixed amount, either two times (2X) or three times (3X), according to the ordering option. Only

those monitors ordered with this option will be affected. The Trip Multiply function is performed in

the System Monitor, but is an ordering option for each monitor. It must be specified at the time of

order placement and be installed at the factory.

Trip Multiply is activated by contact closure on the PIM. A red LED on the System Monitor front

panel indicates that the Trip Multiply function is active.

OK RELAY

The purpose of this relay is to provide a means to annunciate a problem that is detected with any

transducer system connected to the rack. The OK Relay is connected to the OK Circuit of every 

monitor in the rack. The OK Circuit continuously checks the condition of the transducer(s)

associated with that monitor. If the circuit detects a transducer problem, the OK LED on the front

of the affected monitor goes off and a relay drive signal is sent to the OK Relay in the System Monitor.

The OK Relay is located on the System Monitor PIM, is normally energized, and is a single-pole,

double-throw (SPDT) relay. Since it is normally energized, the relay also can be used to

annunciate when mains power to the rack is lost or interrupted. Either a system power-up inhibit

signal from the System Monitor or a not OK signal from any monitor in the rack will cause the OK

Relay to change state.

ALARM SETPOINT ADJUST

The System Monitor has two switches on the front panel that adjust alarm setpoint levels on each

monitor. One switch is for upscale adjustments, and the other switch is for downscale

adjustments.

DATA INTERFACE

The System Monitor supports the following Bently Nevada data interfaces: Dynamic Data

Manager (DDM), Transient Data Manager® (TDM), Serial Data Interface (SDI), Dynamic Data

Interface (DDI) and Transient Data Interface (TDI). The SDI and DDI are options of the System

Monitor and reside within the System Monitor slot of the rack. DDM, TDM and TDI are external

data interfaces which gain access to the rack through the PIM. There is an external version of the

SDI and DDI which connects to the PIM. For more information about these products consult a

Bently Nevada sales representative.

Keyphasor® TRANSDUCERS

The System Monitor receives input from four Keyphasor® transducers through terminals on the

PIM. Two of the Keyphasor® transducers are available to the monitors within the rack. All four of

the Keyphasor® transducers are available to the Dynamic Data Interface (DDI). Buffered

Keyphasor® signals are also available from the coaxial connectors on the front panel. The System

Monitor also provides short-circuit protected Keyphasor® transducer power.

STATIC DATA BUS BUFFER

The System Monitor multiplexes signals from either the DDM or TDM to select static data

from the monitors. The System Monitor buffers the static data signals sent from the

monitor to the DDM or TDM.