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www.elspec-ltd.com | December 2014 | SMX-0609-0101
User Manual | EQ-ST | V15
S
CAN
M
ODE
Use this parameter to activate or de-activate the Scan mode.
With Scan mode activated, all capacitor groups are connected and disconnected continuously. This mode
enables uniform utilization of the capacitor groups and therefore reduces the average current of each group
by the ratio of the number of groups connected to the total number of groups.
For example, for a six-capacitor group bank with a nominal current of 100 A per group, the actual current is
120 A per group because of the harmonics present. With Scan mode inactivated, the groups that are on will be
loaded by 120%. Assuming that only 3 groups are required, each one of the six groups will carry an average
current of
A
groups
groups
A
60
6
3
120
, which is 40% less than the nominal.
Note that, when the system connects and disconnects groups in automatic mode, the Scan Mode is
temporarily disabled since the automatic mode connects and disconnects the groups in a circular order (FIFO,
first in, first out), thus achieving the same functionality.
Figure 60 shows a typical scanning routine of three capacitor groups with a six-group capacitor bank.
Figure 60: SCAN Sequence Example