Safety Functions; Power Failure - Edwards STP-iS1607 Series Instruction Manual

SAFETY FUNCTIONS

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The STP pump is provided with safety functions for various abnormalities/errors. When two or more
warnings are detected simultaneously, a high-priority warning is indicated. Also, the warning signal is
output from the "X2 REMOTE" connector. If an abnormality/error is found when using the STP pump,
check it and take measures in accordance with the following procedures. If you cannot trace it or if
the STP pump does not function normally after the troubleshooting, contact Service office.
7.1 Safety functions
Note: The flashing pattern of the "FAILURE" LED (red) indicates the type of failure.
Refer to Section 7.6, "Troubleshooting" for details.
7.1.1

Power Failure

When the power voltage drops below 160 V due to a power failure or another fault, the normal
operation of the magnetic bearing is maintained at the high rotational speed using the regenerative
energy of the rotating rotor (backup operation during a power failure).
The lowest rotational speed to which the magnetic bearing can operate at a power failure is called a
backup rotational speed.
1. When the rotational speed is approx. 6,000 rpm or more at a power failure:
The STP pump detects any power failure of 2 seconds or more and decelerates. At this time, the
"POWER" LED extinguishes and the "FAILURE" LED (red) illuminates. Also, a failure signal is
output from FAILURE OUT pins (8)-(21) and (9)-(21) of the "X2 REMOTE" connector.
When the rotational speed goes down to approx. 6,000 rpm, the rotor lands on the touch down
bearing and stops. All LCDs extinguish.
The STP pump does not detect a power failure of less than 2 seconds and the STP pump will
continue to rotate. Moreover, the STP pump does not detect a power failure during decelerating.
2. When the rotational speed is less than approx. 6,000 rpm at a power failure:
The STP pump does not detect the power failure. The rotor lands on the touch down bearing
and stops.
STP-iS1607 Series Turbomolecular Pump
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MT-94E-001-C
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