Multi-Tech Systems 7500 - Manual (Page 292)

Introduction ION 7500 / ION 7600 User’s Guide
Page 292 Power Availability Technical Note
Introduction
Power availability predicts, based on historical data, the probability that a specific
power system will be functioning in its correct state at some point in the future.
The availability calculation measures the time that power was available at the
meter’s monitoring point. This value can be used alone or incorporated with other
reliability calculations.
Typically, a utility distribution system provides an availability of approximately
99.9%. Many applications require better availability than this: up to 99.9999% or
better. At this level, the number of consecutive nines becomes difficult to
determine at a glance. High levels of availability are commonly referred to as
“Number of Nines”: 99.9% corresponds to 3 nines; 99.9999% is 6 nines.
Once the meter is installed, the availability calculations must be reset to ensure
valid time counts. You can reset availability calculations using ION
®
software. In
the case of ION 7500 and ION 7600 meters, availability can be reset via the meter’s
front panel. You can also pause availability calculations for meter maintenance or
decommissioning purposes (refer to “Resetting and Pausing Power Availability”
on page 295).
Availability Framework - Release History
* Requires proper configuration of the Sag/swell module to record system disturbances.
Firmware
Versions
Release Dates Availability Features Comments
V209 - V231
November, 00
to March, 03
◆ Arithmetic modules compare the last-stored time before
the meter went down with the time the meter regained
power.
◆ Uptime calculates using a seconds counter and the down-
time is added to provide the total uptime.
◆ Disturbance time taken from the Sag/Swell module and
downtime is added separately.
◆ ‘Include meter downtime’ allows users to ignore planned
outages.
Availability implementation
requires no user setup - if the
meter loses power this is reflected
in the Availability calculation.*
V240 March, 03
◆ Sag/Swell module in ION 8000 Series meter modified to
record an outage when the blade-powered meter is
unpowered.
◆ Diagnostics module records meter outage duration.
Availability implementation
requires no user setup.*