Generator Operation

The gensets are the diesel generators that can provide power if there is (or is likely to be) a disruption to the mains electricity supply. Each antenna as well as the control building has its own genset.

Generators should only be started by people who have been trained to do this. Starting and stopping generators should be logged in the site log book

On the antennas, there are synchronisers to ensure that that there is no break in power. When a generator start request is sent to the antenna, the antenna generator is started, and when the synchroniser detects that the generator is running and stable, the load is gradually switched from mains to generator. Once the generator takes the full load, the mains breaker is opened. Turning generators off is basically the reverse of this.

If the mains power fails and the generators are not on, this will be detected and the generators will automatically turn on and take the load (though the antenna drives, cryogenic compressors etc. will have a power break, and may need to be restarted). If the generators are started automatically, they will turn off automatically when mains power is restored.

When to Use Generators

Although the generators will start automatically if the power fails, the generators should be started when there is imminent likelihood of:-
  • Storms, as indicated by one of:
    • The lightning monitor in Monica
    • The Moree weather radar
    • The country energy stormtracker
    • Going outside and assessing the approaching weather!
  • A scheduled outage has been announced by the electricity supply authorities.

Generally, generators should be started after one power 'glitch', especially if it's obvious that a storm is approaching (or in any situation where it is likely that power failure will happen.)

Starting the GENSETs before actual power failure is useful for several reasons:

  • It lessens the chance of failure to stow at a critical time (e.g., when the antennas are in the process of being windstowed),
  • It isolates antennas and the control building from power surges that might be associated with the storm,
  • It means that if there is any problem starting a GENSET, there is time to fix it before it is really needed.
In the event of an unscheduled power failure, notify Country Energy (the local power distributor).

Starting the Generators

Computer control of the GENSETs is performed from caobs. The actual commands are:
caobs> set genset_on ALL
caobs> set genset_off ALL
This will operate all generators including the Control Building Generator.

Individual antennas are selected by replacing ALL with the antenna number e.g.
caobs> set genset_on CA06
and to start the control building generator only,
caobs> set genset_on CB

These commands will only work for antennas which are attached.

There is no automatic monitoring to check that the generators actually turn on. If the generator doesn't turn on, the only consequence (until the power actually drops out) is that the generator doesn't turn on. Therefore, the operator must check explicitly that the power supply has switched to generator. This can be done by:

  • The genset idle light in the PMON rack goes out and the mainsfail light is activated. There should be a few minutes where both lights are out, before the switch to generator is completed.
  • The power/generators page in Monica (look under favourites) show the generators have started.

If a generator does not come on, it is critical that you contact an on-call person straight away.


Generators should be turned off again after the mains power has returned to normal, and you are confident that there will be no further disruptions. For storms, it is a good idea to remain on generators until after the storm has moved beyond Narrabri (assuming that they are moving west to east).

Notifying Essential

In the event of a significant unscheduled power failure, Essential Energy should be notified. Note that CA06 receives its power from a different feeder to the rest of the site (CA06 and SUSI power comes from Wee Waa, the rest of the site is fed from Narrabri).
Ring (0) 13 2080 to report the loss of supply and tell them:

  • Who we are - CSIRO Australia Telescope, Paul Wild Observatory
  • Our premise numbers are
    • 130678 for the ATCA central area and railtrack
    • 132792 for CA06
    • 114481 for Mopra
  • who you are and a number you can be contacted on.

Request an estimate of the time of the outage, and if they are not able to give you this, ask them to ring you back when they do know.
It is important that the Site Services Staff are notified if the outage is for more than 12 hours (notify the on call person) so that they can check (and if necessary) refill the fuel tanks.


Original: Derek McKay (17-Oct-1995)
Modified: Robin Wark (20-Feb-2013)