Operation Manual

MI 2092 Power Harmonics Analyser Section VI Theory of operation
55
5. Power breaks recording
If data logging is in progress, the start of every OFF state of the instrument is treated as
a Power Break. This OFF state occurs either if the instrument is switched OFF (using
the rotary switch) or if it lose its power supply.
For each Power Break, the instrument logs the date & time of both the beginning and
end of the power break, and the cause of the power break (manual or loss of supply).
Note: The battery must be in the instrument otherwise its power supply drops
to fast and it can not records Power Break.
6. Memory usage
The non-volatile memory in the Instrument can be used in one of two ways:
Linear mode
In linear mode recording, the Instrument stores data in memory until full and then stops
recording. Thus the oldest data is always preserved irrespective of the amount of
recordable data.
Roll-over mode
When recording in roll-over mode, the Instrument will over-write old data when
memory is filled. Thus, the latest data is always preserved irrespective of the amount of
data recorded, with the older data being possibly lost.
Data logging capacity in linear mode depends on the number of channels selected for
recording, the type of data recorded, the IP and the number of voltages anomalies
detected. It is automatically calculated by the PC software when selecting channels for
logging and is given by the following equation:
Maximum number of records in Periodic Analysis (Rn
max
) is given by:
Rn
NN
R
Statano
len
max
()**
=
-
-
20321024164
Where:
R
len
Record length RXY
len
=
+
+
12612**
N
stat
N° of channels selected for Statistical Analysis
(All being selected for Periodic Analysis, but excluding harmonics).
N
ano
N° of voltage anomalies which occurred while recording.
X N° of channels selected excluding power channels (±P
x
, ±Q
x
, ±P
tot
, ±Q
tot
, ±S
tot
).
Y Power channels
Note: Estimating Voltage Anomalies: