Power Outage

During winter ice storms or heavy snow, or late Spring electrical storms, or simply routine maintenance in Shutesbury, power to the site may be interrupted. Electrical power is distributed to the observatory from the power shed located just west of the observatory machine shop. A switch is located within this shed which senses power surges and drops. If the variation in power is greater than or less than some tolerance, the switch shuts down power to most of the observatory. In the event of a power outage:

1. Emergency lighting should come on. In addition, flashlights left in selected 110V sockets are available. These should automatically turn on
2. Once you can safely move around the site, place the MODCOMP in HALT and turn off the disk drives.
3. Disable power to the antenna

Since the phone system requires electrical power to operate, there is a UPS available to temporarily run the phones to make an phone call. The user needs to walk down to the radio room located 2 doors down from the door to the radome. At the bottom of the rack, there is a box with a light and timer. If the light is on, then one needs to set the timer (say for 15 minutes) in order to temporarily operate the phone system. The limited time allows for conservation of the battery.

In the summer of 1994, the infamous ``black button'' to restore power to the site if available was replaced with a new electrical switch. Now, the power will automatically be restored if the power level is not fluctuating for more than 90 seconds. Thus, the observer need only wait after following the above sequence.

With power restored throughout the site, there may still be several loose ends to resolve.

1. If the power was out for longer than an hour, the SEQUOIA dewar has likely warmed up and therefore, needs to be pumped back down. Check the status of the receivers on the platform (see Trouble Shooting Guide in Appendix C). If the dewar has warmed up, call the staff.
2. Check the circuit breakers in the long hallway between the library and the stairs to the dome. These circuit breakers control the vents and fans inside the dome. If these have been tripped, reset the circuit breakers.
3. The circuit breaker which controls the environment in the annex often is tripped in the event of an outage. It is located in the corner of the annex behind the instrument racks. Enter the closet. There is a white button located on the furnace to the left as the user enters. Press the white button.

At this point, the observatory should be back to normal and ready for more observing. If so, see Chapter 1 for rebooting the MODCOMP and starting the tracking programs.