How to Retain Vacuum on an Elekta LINAC During a Power Outage

By Andrew Woodbury, Field Engineer for LINAC Systems

Temporary power outages in a medical facility are never convenient, but lengthy outages can result in more than just postponed cases and lost revenue. 

If proper precautions aren’t taken to preserve equipment during power outages, major equipment systems can require additional work to restart once power has been restored. This is especially true when it comes to LINAC systems. In this article, you will learn how to preserve the vacuum on an Elekta LINAC in the event of a power outage.

If an Elekta LINAC is without power for more than four hours, power should be maintained to the ion pumps by using a backup generator. Losing vacuum in the waveguide could possibly cause days of unwanted downtime. The easiest way to avoid downtime is to incorporate backup power outlets running from a generator. Connect a standard computer power cord with IEC C13 and NEMA 5-15 connections to an extension cord from the backup power outlet to the ion pump power supply unit (PSU).

Most Elekta machines power the ion pumps with a single Agilent Technologies model switching PSU which uses a 100-240V input. Do not attempt this backup power installation process with older PSU models (Edwards or similar) as they only operate on 230V. 

Begin by rotating the gantry to -45°angle. Next go behind the left door of the machine and turn to your right to see the ion pump PSU at eye level inside the gantry drum.

Shut off the rocker switch and unplug the ion pump PSU power cord directly to the right.

Next, plug in the computer power cord to the ion pump PSU and the extension cord to the backup power outlet. Flip the PSU rocker switch back on. On the opposite side of the PSU, two blue lights should blink, and then go solid.

After you have secured backup power to the ion pump, be sure to shut down the LINAC computer all the way by clicking Power Off at the standby screen. Make sure the XVI, iView, iGuide, Sequencer and any other computer systems are shut down as well.

Taking the above steps will help to ensure that your Elekta LINAC will safely weather the power outage and avoid costly downtime. Once power has been restored to your facility, do not rotate the gantry until the external power cord is disconnected. Flip off the rocker switch on the ion pump PSU and remove the computer power cord. Plug in the original power cord and flip the power switch back on. Once again, the blue LED lights should blink and then go solid. If these lights continue to blink, or do not turn on at all, contact your local LINAC service engineer for assistance.