Why does the Series 3000/4000 Circuit Monitor display show stars or asterisks for frequency?

Issue
Why does the Series 3000/4000 Circuit Monitor display show stars or asterisks for frequency?

Product Line
CM3000 and CM4000 series meter

Cause
Customer see stars or asterisks for frequency on CM3000 or CM4000 front display.

Environment
Reading Frequency from front display on CM3000 or CM4000 meter.

Resolution
There are several possibilities in which this could occur:

1. The frequency is changing too quickly. (Possible causes could be when monitoring a Generator that has not stabilized the voltage frequency)
2. The voltage on phase A and C has dropped to zero. (Normal)
3. (CM4000 series only) The Current Voltage Module (CVM) module is not properly seated. (NOTE: In this instance cycling control power to the meter will not help.)
4. (CM4250 Only) This symptom can also be caused by the temperature chip in the meter when the firmware version is earlier than 14.4. To confirm this is the issue read register 3238. If the value is zero, then this may not be the issue.  If 3238 isn't zero use the command register writes as shown below to write to 3238 a zero.  It is recommend that the firmware be upgraded to the latest version available.

Note: Write to one register at a time in the specific order above.

Publikováno pro: Schneider Electric Česká republika