SIEMENS
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Siemens IC 10 · 2017
Relays
SIRIUS 3UG45, 3UG46 Monitoring Relays for Stand-Alone Installation
Speed monitoring
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Overview
SIRIUS 3UG4651 monitoring relay
The 3UG4651 monitoring relay is used in combination with
a sensor to monitor motor drives for overspeed and/or under-
speed.
Furthermore, the monitoring relay is 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
•
Can be used worldwide thanks to wide voltage range from
24 to 240 V
(absolute limit values)
•
Variably adjustable to overshoot, undershoot or range
monitoring
•
Freely configurable delay times and RESET response
•
Permanent display of actual value and fault type
•
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
3UG4651 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 0.1 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 s, by connecting the
RESET device terminal to 24 V DC or by switching the control
supply voltage off and back on again.
© Siemens AG 2016