| 摘要 |
A control system used to monitor an AC power source connected to AC powered user equipment. The control system is designed to monitor the output voltages of the AC power source to ensure that they are maintained within a predetermined operating window consisting of a high voltage limit and a low voltage limit. If the voltages stray outside the operating window the control system activates a normally closed DC relay to disconnect the AC power source from the AC powered user equipment. The disconnection is immediate for voltages that stray above the high voltage limit and only occurs after a short delay for voltages below the low voltage limit. The control system also monitors the AC power source connection to the AC powered user equipment to ensure that no polarization errors exist in the connection. A polarization error exists when the output conductors of the AC power source are connected to the wrong input conductors of the AC powered user equipment or when one or more conductors of the AC power source are not connected at all. The control system immediately disconnects the AC power source when a polarization error is detected. The control system is able to reconnect power to the AC powered user equipment after a minimum delay time has elapsed when it determines that the voltage is within the operating window again or the polarization error has been corrected. The control system is powered by an independent DC power supply separate from the AC source being monitored.
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