Emerson Vilter VilTech, Operation And Service Manual

Page: 36 / 174

36
Alarms & Failures
The Viltech continually monitors the system parameters and compares them to
A
LARM AND
F
AILURE
setpoints
to inform the operator of the system status. An alarm is intended to alert the operator that an undesirable
condition exists. A failure is an indication that a more severe system condition exists and may cause the system or
component to shutdown. The system parameters are compared to both operator-defined setpoints and Vilter
Manufacturing, LLC. safety setpoints. An alarm or failure is detected when a system parameter is outside the
acceptable range of the setpoints.
Certain alarms and failures may also be suppressed under specific conditions. For example, the low oil pressure
alarm is suppressed when the compressor is not running. Additionally, the detection of certain alarms and failures
can be delayed. For example, the low suction pressure failure is delayed for 10 seconds, in other words the suction
pressure must be below the low failure setpoint for 10 consecutive seconds before the system is shutdown.
Some alarm and failure setpoints are assigned factory default values, which may not be changed by the operator.
These are called OEM safety setpoints and typically indicate a condition that may cause damage to the equipment.
A detailed list of all system alarms and failures can be found in Appendix A.
When an alarm or failure is detected the sequence of operations is as follows:
The equipment controlled by the Viltech may be stopped, as in the case of a compressor, when a failure occurs.
The alarm or failure is entered into the active alarm and failure list and the current status screen on the
display is replaced with the active alarm and failure screen.
An entry is made in the appropriate alarm or failure log.
A special entry is made in the operation and trend logs listing the parameter values at the time of the alarm or
failure.
The current alarms and failures present on a system can be viewed on the active alarms & failures status screen.
The operator must acknowledge and clear alarms/failures from this screen or the main status screen using the
procedures covered in this section.
When a new alarm or failure becomes active, the Active Alarm & Failure status screen will be displayed as the
default status screen. The user can view all of the active alarms by scrolling through the alarms using the up and
down arrow keys. An example of the alarm & failure status screen is shown on the next page.