GE 750 Instruction Manual page 226

S6 MONITORING
5 - 100
whered = demand value after applying input quantity for time t (in minutes),
D = input quantity (constant), k = 2.3 / thermal 90% response time.
100
80
60
40
20
0
0
FIGURE 5–40: Thermal Demand Characteristic (15 minute response)
The 90% thermal response time characteristic defaults to 15 minutes. A setpoint
establishes the time to reach 90% of a steady-state value, just as the response time of
an analog instrument. A steady state value applied for twice the response time will
indicate 99% of the value.
• Block Interval: This selection calculates a linear average of the quantity (RMS current,
real power, reactive power, or apparent power) over the programmed demand time
interval, starting daily at 00:00:00 (i.e. 12 am). The 1440 minutes per day is divided into
the number of blocks as set by the programmed time interval. Each new value of
demand becomes available at the end of each time interval.
The Block Interval with Start Demand Interval Logic Input calculates a linear average
of the quantity (RMS current, real power, reactive power, or apparent power) over the
interval between successive Start Demand Interval logic input pulses. Each new value
of demand becomes available at the end of each pulse. The

FUNCTIONS START DMND INTERVAL
demand interval pulses.
• Rolling Demand: This selection calculates a linear average of the quantity (RMS
current, real power, reactive power, or apparent power) over the programmed
demand time interval, in the same way as Block Interval. The value is updated every
minute and indicates the demand over the time interval just preceding the time of
update.
kt
–
d t ( ) D 1 e ( )
= –
3 6 9 12 15 18
Time (min)
setpoint programs the input for the new
750 FEEDER MANAGEMENT RELAY – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTS
(EQ 5.20)
21 24 27 30

S3 LOGIC INPUTS MISC