SIEB & MEYER SD2, Перевод оригинальной инструкции

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3 Safe Frequency Monitor (SFM)
The function “Safe Frequency Monitor” (SFM) allows detecting a standstill of an electric
motor. In this case a standstill corresponds to a rotating field frequency up to the para‐
meterized limit value.
This safety function is used for rotating axes, e.g. drilling and routing spindles. You can
parameterize the SFM function, for example, with a limit frequency of 10 Hz – up to this
frequency the risk of injury due to rotating tools, e.g. drilling or routing tools, is consid‐
ered low. Thus, entering the danger area is deemed 'safe'.
The threshold of the frequency monitor depends on the used spindle and must be
determined according to the specific application.
The function is implemented as sensor signal. That means, the function can detect the
actual frequency of the motor but cannot limit the rotating field frequency. For this
purpose you can use the function SLOF (see page 17 ) or STO (Safe Torque Off).
3.1 Functional Description
The SFM function is based on a frequency-dependent voltage that is induced by the
motor or the remanence. This voltage can be measured at the motor terminals, regard‐
less whether a synchronous motor or an asynchronous motor is used.
From that voltage the drive determines the actual rotating field frequency and
compares it with the parameterized limit value (see chapter 5 "Parameterization of the
Limit Frequency", page 23 ). If the rotating field frequency is within the parameterized
range, the drive generates the status signal STANDSTILL and the OSSD relays are
closed.
The drive only generates the standstill signal when the output stage is deactivated and
the main voltage is switched off, that means:
▶ With 3-phase mains supply the phases L1, L2 and L3 must be disconnected.
▶ With 1-phase mains supply the phases L1 and N must be disconnected.
When the output stage is active and/or the main voltage is switched on, the status is
always NO_STANDSTILL and the OSSD relays are open.
If you parameterize the limit value zero, standstill monitoring is deactivated and the
OSSD relays are closed.
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Safe Frequency Monitor (SFM)
Drive System SD2 - Safety Functions SFM / SLOF 11
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