User-Programmable Leds - GE L90 Instruction Manual

PRODUCT SETUP
d = demand value after applying input quantity for time t (in minutes)
D = input quantity (constant)
k = 2.3 / thermal 90% response time
The figure shows the 90% thermal response time characteristic of 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 indicates 99% of the value.
5.3.10.2 Calculation method 2: Block interval
This method 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 (that is, 12:00 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.
5
5.3.10.3 Calculation method 2a: Block interval (with start demand interval logic trigger)
This method 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. Assign a FlexLogic operand to the
demand interval pulses.
If no trigger is assigned in the
calculation method 2. If a trigger is assigned, the maximum allowed time between two trigger signals is 60 minutes.
If no trigger signal appears within 60 minutes, demand calculations are performed and available, and the algorithm
resets and starts the new cycle of calculations. The minimum required time for trigger contact closure is 20 µs.
5.3.10.4 Calculation method 3: Rolling demand
This method 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.

5.3.11 User-programmable LEDs

5.3.11.1 Menu
SETTINGS  PRODUCT SETUP  USER-PROGRAMMABLE LEDS
 USER-PROGRAMMABLE
 LEDS
5-106
Figure 5-43: Thermal demand characteristic
DEMAND TRIGGER
setting and the
DEMAND TRIGGER
 LED TEST


 TRIP & ALARM LEDS


setting to program the input for the new
CRNT DEMAND METHOD
See below
See page 5-109
L90 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETTINGS
is "Block Interval," use