Multi-Tech Systems 7500 - Manual (Page 64)

Demand Setup ION 7500 / ION 7600 User’s Guide
Page 64 Chapter 3 - Default Meter Functionality
Changing the Parameters that are Displayed
The meter’s default display configuration shows a comprehensive set of
parameters. Changing these parameters requires that you alter the links between
various ION modules. Complete details on configuring the front panel displays
are provided in the Custom Front Panel Displays technical note in the Appendix A.
Demand Setup
Demand is a measure of average power consumption over a fixed time interval.
Peak (or maximum) demand is the highest demand level recorded over the billing
period. Two methods of measuring demand are with Thermal Demand modules
and Sliding Window Demand modules. These 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