Yokogawa PR300 Power and Energy Meter - Manual (Page 55)

4-14 IM 77C01E01-01E
4.7 Demand Measurement (Optional Measuring Function)
Demand Alarm
Demand alarm output
Function: When the set demand alarm point is exceeded, an alarm is output.
Output signal: Open collector
Output capacity: 30 V DC, 200 mA
Demand alarm release function
Automatic release: When the demand value falls below the demand alarm point, the alarm is canceled.
Manual release:
The state of the alarm is maintained even if the demand value falls below the
demand alarm point. It is canceled via communication or by digital input or the
operation key.
Digital input Number of inputs: 1
ON signal: 4.5 to 25 V DC
OFF signal: within Ϯ1 V DC
Demand alarm mask time
The demand alarm mask time is the time between the beginning of the demand period and the set time,
during which a demand alarm is not recognized.
Example Demand Measurement
0 10 20 32 30
100
200
300
400
500
(kW)
Demand period:
10 minutes
Demand period:
10 minutes
Demand period:
10 minutes
Demand measuring time: 32 minutes
(update interval: 10 seconds, times of measurement: 192)
Demand power
Demand alarm point
Demand alarm
mask time
Time (min)
Active power (kW)
Active energy (kWh)
Does not turn on
in the demand
alarm mask time.
turns on
during the
demand alarm.
Maximum demand value
Demand alarm output (open collector)
In conjunction with the demand alarm lamp, the
demand alarm output keeps sending an alarm until cancellation.
To manually cancel
the alarm,
press once or perform the
cancellation procedure via communication.
The alarm can be canceled by the operation key
or via communication regardless of the status
of the start/stop operation.
When the demand
alarm release function
is set to “Automatic
release,” the alarm is
automatically canceled
when the demand value
falls below the alarm
point.
Maximum demand value
The maximum demand value is the maximum value in the demand measuring time. This value is retained
until system reset or start of the next demand measurement.