Operation Counter Data - The <Counters> Menu - Siemens MJ-4A Installation And Operation Manual

5
Reading and Interpreting MJ-4A & MJ-4B Control Panel Data
5.7 Operation Counter Data -
the <COUNTERS> Menu
Operation counters record the stepping operations of the
regulator tap changer (see Table 5.7).
Table 5.7 Counter Data Items
Total Ops The total number of tap changes
Reset Date of last Elapsed Ops counter reset
Reset Time of last Elapsed Ops counter reset
Elapsed Ops Total number of tap changes since last reset
24 HR Ops Number of tap changes in the past 24 hours
30 Day Ops Number of tap changes in the past 30 days
MTD Ops Number of tap changes this month
Last Month Number of tap changes last month
YTD Ops Number of tap changes this year
Last Year Number of tap changes last year1
Tap Present position of the tap changer
Tap Control Remote or Local based on the mode setting
Tapmax Maximum tap position since last reset
Tapmin Minimum tap position since last reset
1. To reset, use Cancel/Reset key.
2. To change value, use the Change/Scroll/Save keys.
3. Tap position is determined by the "dead reckoning" method
(see below)
4. To view, use Max/Min key.
To retrieve Tap Changer data, use the Menu Selection
keys to access the< COUNTERS> Menu; then use the
and keys to sequence through the data.
Siemens Energy, Inc.
Dead Reckoning for Siemens Regulators
The control program keeps track of the regulator tap posi-
tion by means of a "dead reckoning" procedure, analo-
gous to navigational dead reckoning. Dead reckoning must
start from a known position. MJ-4 dead-reckoning begins
at Neutral (U12 active, if Tap Resync is ON) or when an
operator inputs a tap position value. Subsequently, when
the microprocessor requests a tap raise/lower (J/K), and
2
the regulator makes the tap change (asserting Operations
Count signal U10), the control program updates the tap
1
position value. By this procedure, the MJ-4 maintains con-
1
tinuous tap position information.
1
1
If, for some reason, a tap change command is not con-
1
firmed within an appropriate period of time, a Message
1
condition is raised and dead reckoning is discontinued
until the tap changer once again signals Neutral. Similarly,
1
a Message condition is activated if an Operation count sig-
1, 3, 4
nal is received when no tap change command was issued;
1, 3, 4
or if the U12 PDS lead signals that the tap changer has
passed through neutral at a time when the
dead-reckoning position is not neutral.
Note: For application on other manufacturer's regula-
tors and LTC apparatus, the MJ-4 implements
a similar dead reckoning procedure for tap
tracking. The details of the tap tracking
approach for these applications are included in
the Tap Tracking Application Note.
assumed