Samson 3738-20, Монтаж и эксплуатация

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EB 8390 EN 49
Operation
9 Operation
WARNING!
The actuator shaft/stem moves while
the electronic limit switch is operat-
ing.
Do not touch the actuator shaft/stem
or obstruct it to avoid risk of injury to
hands or fingers.
9.1 Lock operation
When the locking function is active, the elec-
tronic limit switch can only be operated re-
motely using the TROVIS-VIEW software. The
locked on-site operation of the electronic lim-
it switch is indicated on the display by the
icon.
The on-site operation is locked and unlocked
in the TROVIS-VIEW software.
9.2 Partial stroke test (PST)
WARNING!
Ear protection must be worn if the
test is performed on the version with
integrated solenoid valve while the
housing cover is open.
The probability of failure on demand (PFD)
can be reduced and maintenance intervals
can be extended by the partial stroke test
(PST).
This helps prevent the valve from seizing up
in its operating position.
The following conditions must be met before
the partial stroke test (PST) can be per-
formed:
−
An automatic initialization must have
been performed (see section 8.7.1).
− The switching voltage must be applied.
Test procedure (Fig. 16)
The electronic limit switch issues pulses of
various lengths to the solenoid valve (briefly
de-energizing it) during the partial stroke test
(PST), moving the valve further towards the
fail-safe position.
The test has been completed successfully
when the valve has reached the target range
('PST step end' ± ½ 'PST tolerance band') by
one pulse, but not exceeded it. When the tar-
get range is reached, contact C responds
The analysis of a successfully completed test
provides the following data:
− PST pulse length
− PST dead time
− PST transit time SV de-energized
− PST hold time
− PST transit time SV energized
− PST travel
− PST status
If the test could not be completed, the corre-
sponding F8 or F9 status message is gener-
ated:
− F8 : No switching voltage during PST
− F9 : Time-out during PST
Note:
−
If the travel of the PST is monitored
and, if necessary, the status mes-
sages F6 ('Min. value for PST not
