The DIRC PMTs are powered with High Voltages (HV) and so one must be very cautious when performing any operation on them. The most important safety information is summarized in this section. For more detailled shifter-related information, have a look at the instructions to recover a failed DIRC HV supply from where the pictures show below are taken.
Figure 1 shows a front view of 1 of the 6 DIRC HV crates located in the electronic house.
The status of the HV crate is shown on the LCD display at the top left of the crate. Switching ON/OFF the crate is done by plugging a key on the bottom left key switch: one quarter on the left to switch it on, one quarter on the right to switch it off. There is a single key for the 6 crates and so it must always be left plugged on the last crate switched on when all DIRC HV are on.
While you're working on a HV crate, keep the key in your pocket to be sure that nobody will try to switch the crate on in the meantime. In addition, let you name close to the crates and provide a way to join you in emergency (pager, cell phone number) if needed.
If an HV crate is off and the key available, do not switch it on before you're 100% sure that nobody is working on its HV. In case of doubt page the DIRC commissioner or mail babardrc.
Figure 2 shows a back view of 1 of the 6 DIRC HV crates located in the electronic house.
The cables plugged on the HV boards power the PMTs in HV: do not touch them. Before starting any work on the boards, be sure to have done the following steps.