Mitsubishi Electric NF400-HEW, Инструкция по эксплуатации

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(4) Intermittent load (such as welder) measurement
Items such as current, voltage, and electric power are measured (sampled) once every 250 ms. Any values, such as current value, are calculated
and the measurement value is updated at this timing.
However, the minimum update cycle for measurement results displayed on the display or output over communication data is 500 ms.
This will result in a larger errors if there is a continuous load (such as due to a resistance welder), and is therefore not suited for measurement in
such cases.
If a subordinate circuit breaker operates during a short or earth leakage, the operating current might be measured at a low value.
Fault current is continuously monitored. However, the operating current of the MDU Breaker itself is measured, so the operating current of a
subordinate circuit breaker cannot be measured.
(5) Operation during power outage/restoration
● The electric energy (integrated value) and reactive energy (integrated value) are stored in non-volatile memory when measurement values
are updated or there is a power outage. When power is restored, it will continue measuring from the data that was stored prior to the power outage.
● Setting values are stored in non-volatile memory when set, so they do not need to be set again when power is restored.
● The device stores the last measurement display screen status prior to a power outage, and will return to this screen when the power is restored.
● The time setting might not be retained during a power outage. It should be reconfigured when power is restored. This setting is required to
measure the
“
maximum value occurrence time
”
and
“
latest one hour amount
”
(the one hour amount from one hour to the next hour as measured
by the internal clock).
● Maximum values and occurrence times are stored every 30 minutes. If there is a power outage, the data from 30 minutes prior to the power
outage until the power outage may not be stored (in the worst case scenario).