Specifications

Reference Manual
MHM-97408, Rev. 2
June 2008
2-11
CSI 9420
If all else fails, one “rule of thumb” for vibration is to examine the current level
at which the equipment is operating. Then, assuming the equipment is in
good working order, set the Advisory level at 2x the current value (or at a
minimum of 0.05 in/sec. RMS, whichever is greater), set the Maintenance
level at 4x the current value, and set the Failed level at 8x the current value.
For example, if the current value for Overall Velocity is 0.1 in/sec., set the
Advisory threshold at 0.2 in/sec., the Maintenance threshold at 0.4 in/sec.
and the Failed threshold at 0.8 in/sec. While Emerson does not condone this
type of vibration program, it can provide a starting point when no other
information is available.
The default alert thresholds for temperature correspond closely to a generic
open drip-proof (ODP) motor with class F insulation and a service factor of
1.15, operating at an ambient temperature at or below 40 °C and at an
altitude at or below 1000 meters. These values are also reasonable
thresholds to use when there is no knowledge of the process, the type of
machinery, or the operating environment. Refer to Appendix C: Velocity,
PeakVue®, and Temperature for more information. The default temperature
levels are shown in Table 2-5.
Table 2-5. Temperature levels
The configurable device alerts include accelerometer bias and supply
voltage. The default settings for these alerts are shown in Table 2-6.
NOTE:
When any measured process parameter (Velocity, PeakVue, or Temperature)
exceds the configured Advise, Maintenance, or Failed threshold, this causes
an “Advisory” indications on a screen that is viewed from AMS Device
Manager (or other graphical host). This indicator itself does not set a status
bit.
Table 2-6. Configurable Device
Alerts
Field Communicator
To configure alarm limits for the variables exposed by the device use fast key
sequence 1,1,6 to navigate to the "Alarm Levels" configuration menu. Based
on the sensor configuration of the device, you will see all the available
parameters that may have user configured alarm limits.
Parameter
Advisory Maintenance Failed
Level Enabled Level Enabled Level Enabled
Temperature
149F
(65C)
Yes 167F
75C
Yes 185F
(85C)
Yes
Parameter
Advisory Maintenance Failed
Level Enabled Level Enabled Level Enabled
Accelerometer
Bias
N/A N/A N/A N/A Below 2V or
Above 3V
Yes
Supply Voltage Below 6.5 V Yes Below 6.2 V Yes Below 5.3V Yes