Schweitzer Engineering Laboratories SEL-734 - Table 4.6 Demand Meter Settings and Settings Range; Figure 4.5 PREDAL Logic

4.10
SEL-734 Meter Instruction Manual Date Code 20090730
Metering
Demand Metering
If the calculation value is above the PREDAL (predictive demand alarm
threshold) setting, the meter asserts the PREDAL Meter Word. When the
value drops below the PREDAL level, the meter deasserts the PREDAL Meter
Word. Figure 4.5 shows the logic used for the PREDAL alarm.
The SEL-734 requires three one-second calculations to be above the PREDAL
threshold or below the threshold in order to assert or deassert the PREDAL
Meter Word bit. This requirement minimizes the number of nuisance alarms
from starting of large loads.
Figure 4.5 PREDAL Logic
Demand Meter
Settings
Execution: every second
Set
Output
executions
Reset
PREDALD
(PREDAL Setting –1) = dropout threshold
(PREDAL Setting) = pickup threshold
PREDALP
Meter
Word
Bit
PREDAL
Group Settings
PRED
k
= value
executions
Enables
EPRED=Y
enable
calculation
EDEM=BLOK
EDEM=ROL
Group Settings
EPRED = Y
3.00
0.00
3.00
0.00
Table 4.6 Demand Meter Settings and Settings Range
Setting Definition Range
EDEM Demand meter type THM = thermal
BLOK = block
ROL = rolling
DMTC Demand meter time constant 1, 5, 10, 15, 30, or 60 minutes
DMSI Demand meter sub-interval See Tab le 4. 2
PDEMP Phase demand current pickup OFF, 0.10–3.20 Amps, secondary
NDEMP Neutral ground
demand current pickup
OFF, 0.10–3.20 Amps, secondary
GDEMP Residual ground
demand current pickup
OFF, 0.10–3.20 Amps, secondary
QDEMP Negative-sequence
demand current pickup
OFF, 0.10–3.20 Amps, secondary
DBLOCK Demand block time OFF, 1–300 minutes
EOIPT End of interval pulse timer OFF, 1–5 seconds
EPRED Predictive demand Y, N
(hidden if EDEM ≠ ROL or BLOK)
PRED Predicted Peak demand quantity Any marked demand metering
quantity from Table H.2 on page H.4
(hidden if EPRED = N or is hidden)
PREDAL Peak demand alarm level 0–999999.99 (hidden if EPRED = N
or is hidden)
Courtesy of NationalSwitchgear.com