Monitor Functions - GE Bently Nevada 3300/03 Operation Manual

3300/03 System Monitor Operation Manual

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

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