8-24
Breaker Monitor and Metering Functions
Date Code 20011205
SEL-311B Instruction Manual
Time = 10 Minutes
The three 5-minute intervals in the sliding time-window at “Time = 10 minutes” each integrate
into the following 5-minute totals:
5-Minute Totals
Corresponding
5-Minute Interval
0.0 per unit
-5 to 0 minutes
1.0 per unit
0 to 5 minutes
1.0 per unit
5 to 10 minutes
2.0 per unit
Rolling demand meter response at “Time = 10 minutes” = 2.0/3 = 0.67 per unit
Time = 15 Minutes
The three 5-minute intervals in the sliding time-window at “Time = 15 minutes” each integrate
into the following 5-minute totals:
5-Minute Totals
Corresponding
5-Minute Interval
1.0 per unit
0 to 5 minutes
1.0 per unit
5 to 10 minutes
1.0 per unit
10 to 15 minutes
3.0 per unit
Rolling demand meter response at “Time = 15 minutes” = 3.0/3 = 1.0 per unit
Demand Meter Settings
Table 8.3: Demand Meter Settings and Settings Range
Setting Definition
Range
EDEM
Demand meter type
THM = thermal
ROL = rolling
DMTC
Demand meter time constant
5, 10, 15, 30, or 60 minutes
PDEMP
Phase demand current pickup
OFF
GDEMP
Residual ground demand current pickup
0.10–3.20 A {1 A nominal}
0.50–16.0 A {5 A nominal}
QDEMP
Negative-sequence demand current pickup in 0.01 A steps
Note
: Changing setting EDEM or DMTC resets the demand meter values to zero. This also
applies to changing the active setting group, and setting EDEM or DMTC is different in
the new active setting group. Demand current pickup settings PDEMP, GDEMP, and
QDEMP can be changed without affecting the demand meters.
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