Demand Setup 9300 Series User’s Guide
Page 52 Chapter 3 - Default Meter Functionality
Demand Setup
The demand modules (both Thermal Demand modules and Sliding Window
Demand modules) are configured to calculate the average current demand and
kW, kVAR and kVA demand. The setup registers in the demand modules define
time intervals for demand calculations, setting the sensitivity of the module’s
operation.
Sliding Window Demand Module Settings
Sliding Window Demand is often referred to as Rolling Block Demand. To
compute sliding window demand values, the Sliding Window Demand module
uses the sliding window averaging (or rolling interval) technique which divides
the demand interval into sub-intervals. The demand is measured electronically
based on the average load level over the most recent set of sub-intervals. This
method offers better response time than fixed interval methods.
Thermal Demand Module Settings
The Thermal Demand module calculates thermal demand over a specified length
of time. It uses a method which is equivalent to thermal averaging. For thermal
averaging, the traditional demand indicator responds to heating of a thermal
element in a Watt-Hour meter. You can adjust the Thermal Demand module's
calculation to mimic this technique by changing the Time Const and Interval setup
parameters.
Setup Register Function Default
Sub Intvl The time, in seconds, in the sliding window demand sub-interval 900
#SubIntvls The number of sub-intervals in the sliding window 1
Pred Resp The speed of Predicted Demand calculations; use higher values for
faster prediction (70 to 99 recommended) 70
Setup Register Function Default
Interval The time, in seconds, in the thermal demand interval 900
Time Const The sensitivity to changes in the source signal; higher values
provide faster response time (common values are 63 and 90) 90