SIEMENS
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Siemens IC 10 · 2017
Relays
SIRIUS 3UG48 Monitoring Relays for Stand-Alone Installation for IO-Link
Speed monitoring
10
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Overview
SIRIUS 3UG4851 monitoring relay
3UG4851 monitoring relays are used in combination with a
sensor to monitor drives for overspeed and/or underspeed.
Furthermore, the monitoring relays are ideal for all functions
where a continuous pulse signal needs to be monitored (e.g. belt
travel monitoring, completeness monitoring, passing monitoring,
clock-time monitoring).
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Benefits
•
Variably adjustable to overshoot, undershoot or range
monitoring
•
Freely configurable delay times and RESET response
•
Display and transmission of actual value and fault type to
controller
•
Use of up to 10 sensors per rotation for extremely slowly
rotating motors
•
2- or 3-wire sensors and sensors with a mechanical switching
output or semiconductor output can be connected
•
Auxiliary voltage for sensor integrated
•
All versions with removable terminals
•
All versions with screw or spring-type terminals
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Application
•
Slip or tear of a belt drive
•
Overload monitoring
•
Transport monitoring for completeness
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Technical specifications
3UG4851 monitoring relays
The speed monitoring relay operates according to the principle
of period duration measurement.
In the monitoring relay, the time between two successive rising
edges of the pulse encoder is measured and compared to the
minimum and/or maximum permissible period duration calcu-
lated from the set limit values for the speed.
Thus, the period duration measurement recognizes any devia-
tion in speed after just two pulses, even at very low speeds or in
the case of extended pulse gaps.
By using up to ten pulse encoders evenly distributed around the
circumference, it is possible to shorten the period duration, and
in turn the response time. By taking into account the number of
sensors in the monitoring relay, the speed continues to be indi-
cated in rpm.
ON-delay time for motor start
To be able to start a motor drive, and depending on whether the
open-circuit or closed-circuit principle is selected, the output
relay switches to the GO state during the ON-delay time, even if
the speed is still below the set value.
The ON-delay time is started by either switching on the auxiliary
voltage or, if the auxiliary voltage is already applied, by actuating
the respective NC contact (e.g. auxiliary contact).
Speed monitoring with Auto RESET (Memory = no)
If the device is set to Auto RESET, the output relay switches to
the GO state, once the adjustable hysteresis threshold is
reached in the range of 1 to 99.9 rpm and the flashing stops.
Any overshoots or undershoots are therefore not stored.
Speed monitoring with Manual RESET (Memory = yes)
If Manual RESET is selected in the menu, the output relay re-
mains in its current switching state and the current measured
value and the symbol for overshooting/undershooting continue
to flash, even when the speed returns to a permissible value.
This stored fault status can be reset by pressing the UP
▲
and
DOWN
▼
buttons simultaneously for >
2.5
s or by connecting the
RESET device terminal to 24 V DC.
With Manual RESET through IO-Link it is possible in addition to
set whether error signals are to be deleted when the control sup-
ply voltage is switched off and on (as remote RESET) or whether
the signals are to be permanently saved even in a voltage failure,
with confirmation possible only through local RESET or via
IO-Link.
© Siemens AG 2016