Multi-Tech Systems 7500 User Manual

Page of 372
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.*