GE F650 - Page 163

5-16 F650 Digital Bay Controller GEK-106310AB
5.2 PRODUCT SETUP 5 SETTINGS
5
Demand module settings are as follows:
Table 5–17: DEMAND SETTINGS
Function permission (Function): This setting enables the demand function.
Demand Method for Current values (CRNT Demand Method): Selection of the demand calculation method for current
values. Available methods are Thermal Exponential, Block interval, and Rolling
Demand.
Demand Method for Power values (POWER Demand Method): Selection of the demand calculation method for power
values. Available methods are Thermal Exponential, Block interval, and Rolling
Demand.
Demand Interval: Integration interval. Available intervals are 5, 10, 15, 20, 30, 60 minutes.
Measurement integration is performed in the period adjusted in the Demand Interval
setting.
Demand Trigger: Operation mode selection for the Block Interval calculation method. This operation
mode depends on the “Trigger Enabled” setting. If trigger enabled is set as disabled,
measurement integration is made in the Demand Interval period. If trigger enabled is
enabled, measurement integration is made during the time interval between two
consecutive pulses of the input assigned as DEMAND TRIGGER INP,. This input is
set at Setpoint > Relay configuration > Protection Elements
Snapshot Events: This setting enables or disables the snapshot event generation for the demand
element.
5.2.6.2 DEMAND CALCULATION METHODS
a) CALCULATION METHOD 1: THERMAL EXPONENTIAL
This method simulates the action of an analog peak recording thermal demand meter. The relay measures the magnitude
for each phase (or three-phase, depending on the case) every second, and it assumes that the magnitude remains the
same until the next update. It calculates the equivalent thermal demand using the following equation:
Where:
D Input signal (constant).
d(t) Demand value after applying the input value during time t (in minutes)
K 2.3 / thermal 90% response time
SETPOINT > PRODUCT SETUP > DEMAND
Setting Description Name Default Value Step Range
Function permission Demand Function DISABLED N/A [DISABLED – ENABLED]
Demand method for current values CRNT Demand Method THERMAL EXPONENTIAL N/A [BLOCK INTERVAL -
ROLLING DEMAND -
THERMAL EXPONENTIAL]
Demand method for Power values POWER Demand Method THERMAL EXPONENTIAL N/A [BLOCK INTERVAL -
ROLLING DEMAND -
THERMAL EXPONENTIAL]
Demand interval Demand Interval 5 Minutes N/A [5 – 10 – 15 – 20– 30–60]
Trigger Enabled Trigger Enabled DISABLED N/A [DISABLED – ENABLED]
Snapshot Event generation Snapshot Events ENABLED N/A [DISABLED – ENABLED]
)1()(
Kt
eDtd
−
−=