Today, we performed the shutdown operations for the Pcal at both end stations in response to the planned power outage.

Remote actions

First, we requested the SAFE state for the Pcal GRDs.
While the GRDs were transitioning to the SAFE state, and before turning off the laser output, we turned off the GRDs.
After confirming this, we turned off the laser output remotely.

Then, we shut down the following servers remotely:

• calexa
• caleyal
• caleya

Note: calexal was not shut down remotely due to the issue described in klog36479.

On-site shutdown procedure (both ends)

1. Turn off the AOM: power off the AOM driver.
2. Turn off the laser source:
   1. Turn the key to switch the laser OFF.
   2. If an external voltage source is connected, turn the output OFF and power it down.
   3. Turn off the laser power supply.
3. Turn off the shutter controller
4. Turn off voltage sources (for shutters, laser source, AOM drivers).
5. Turn off circuits power inside the rack under the Tx module.
6. Shut down the servers (on-site).
7. Turn off UPS units (two units).
8. Unplug the power cords.

Note: For Pcal-Y, the QPD box was already powered off (no power supplied) before starting the shutdown procedure.