The Advanced Photon Source
a U.S. Department of Energy Office of Science User Facility


Below are some F.A.Q. about Safety at the APS

Replacing UPS failed batteries.

As long as the UPS battery pack is enclosed and it is below the "non-QEW" DC battery requirements (<100 volts & <1000watts) replacement can be performed as nonhazardous electrical work.

Working inside of desktop computers

Once the power cord is removed, the unit can be opened and work can be performed on the low voltage "non-QEW" side (<100 volts DC). (no "zero verification" is needed as long as we are not going into the power supply)

Truck-dock liquid nitrogen fill station

The Group Leader can authorized this work then workers can follow the posted procedure or incorporate it into local Liquid Nitrogen work aid.

Off-Hour ESAF Posting

Schedule and contact information: A floor coordinator is always available on-site during the following hours:

• Monday-Friday: 8 a.m. - 10 p.m.

• Weekends: 8 a.m. - 6 p.m.

The MCR operators will not be posting ESAFs during the off-hours. Beamline personnel and users should plan accordingly.

It is preferred that during normal working hours the beamlines find their local Floor Coordinator to post ESAFs. If the local Floor Coordinator is not available, users should contact the on-duty Floor Coordinator using the online Floor Coordinator Request here: A bookmark to this link is useful. Users may still page the on-duty FC using 2-0101, but the online request is preferred.

Proprietary experiment users may still send their experiment end date and time in the off-hours using the online Floor Coordinator Request. The MCR operators will pass on these dates and times to the next on-duty Floor Coordinator during the following morning’s shift exchange.