Each equipment rack on both Detector Stacks (5 on each Detector Stack) has an individual breaker panel. The panels are about 1 foot square and mounted at about chest height. The main breaker in each rack is a shunt trip breaker which will trip off when AC power to the shunt trip circuit is interrupted. This requires manually resetting the main breaker for each of the racks. There is a safety interlock chassis at the top of each rack. All red LEDs on it must be off to be able to reset the main breaker for the rack. If an LED is on, you should attempt to clear the fault by toggling the switch on the left side of the panel. If the LED goes off, the fault is cleared and you may attempt to manually reset the main breaker for the rack. If the LED remains on, the fault is not cleared and the Hall A staff must be notified. If there are no LEDs on and you cannot reset the main breaker, there is most likely no power to the shunt trip circuit and the Hall A staff must be notified.