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EMC Instructions for Power Outages



Contents:
  1. Preparation for announced outage ('Brownout')
  2. When power has been lost ('Blackout')
  3. When power has been restored

Preparation for an Announced Power Outage

Brownouts usually do not affect IR2 power, but only the accelerator and PEP2 infrastructure. Therefore no particular action is required for the EMC.

In the case that IR2 power will be affected, the following steps can be taken:
Unless data is still being taken the EMC frontends can be turned off (this is not a critical measure, i.e. optional):
In the Electronics Hut, press the only button on the 100 LV power supplies located in racks B2603-01/2/3.
This will remove the primary heat source and give the water chiller a chance to cool the end flanges before the outage occurs, avoiding some crystal temperature alarms.


What to do in Case of a Power Outage

In the Electronics Hut, turn off the 100 LV power supplies located in racks B2603-01/2/3. by pressing the button on each front panel.
The idea here is that when power comes back you want to be sure the chillers are running properly before the frontend is powered up. Normally the LV power supplies are interlocked, i.e. turned off automatically in case of a chiller problem. However, in a prolonged outage we could lose power to both chillers and the interlock SIAMs (the SIAMs are on UPS, but eventually the batteries run out). You want to be in full control when power comes back and avoid accidents due to a SIAM being in a wrong state, unlikely as it may be..

Recovering after a Power Outage

In the order listed here,
  1. Convince yourself that all EMC chillers are running properly (fluorinert and water chiller). They should have temperatures and flowrate as posted next to the LED displays on the chillers. The fluorinert chillers should each have four green LEDs lit. For any problems with the EMC chillers contact an expert:
    • the EMC commissioner (see whiteboard for commissioner on duty)
    • any EMC run contact
    • Bill Wisniewski (p. 849-9661)
    • Eric Doyle (x2861)
  2. Check if the diode bias power supply ( red CAEN crate in E-Hut rack B2603-03) has turned on properly. The LCD display should show 'CAEN SY527'. If not, turn the key to 'off' and back to 'on' position. The crate takes a few minutes to boot. If it does not boot properly, press the black RESET button on the red communications module in the EMC-ILK crate (rack to the right of bias supply, top crate).
  3. If UPS batteries have run out: Switch on the two VME crates housing the monitoring (EMC-MON) and interlock (EMC-ILK) IOCs in the top of rack B2603-04. It may take the IOCs a few minutes to reboot. They boot off bbr-srv01, i.e. if this machine needs to be online first. Check if the monitoring (EMC-MON) and interlock (EMC-ILK) IOCs are working properly: can you bring up the EMC EPICS panel and is everything non-white? If not, consult the Monitoring Troubleshooting Page.
  4. From the EMC EPICS panel, click on 'Bias Voltage' and push the green button on the bottom of the panel that appears. You should see all 10 channels ramp up. After a minute, all channels should have settled into their green values for 'Vmon' and 'Imon'. If there is no variation in any of the numbers over more than 30sec the communication to the power supply has broken down. Press reset button on communications module as described above.
  5. Turn on the frontend electronics: In the Electronics Hut, switch on the 10 crates housing the 100 LV power supplies located in racks B2603-01/2/3. The switch is located on the lower left part of the crate (it may already be in the 'on' position, pointing upwards. Then switch on the power supplies by pressing the only button on each front panel. All power supplies should have their green LED lit [picture].
  6. The EMC EPICS panel should have no alarms left. Before taking data the system should be tested with a lightpulser run (central calibration).

Ivo Eschrich
- Valid until modified.