SIEMENS
5/49
Siemens IK PI · 2015
IO-Link
SIRIUS 3UG48 monitoring relays for stand-alone installation for IO-Link
Power factor and active current monitoring
5
■
Overview
SIRIUS 3UG4841 monitoring relay
The 3UG4841 power factor and active current monitoring
devices enable the load monitoring of motors.
Whereas power factor monitoring is used above all for monitor-
ing no-load operation, the active current monitoring option can
be used to observe and evaluate the load factor over the entire
torque range.
■
Benefits
•
Monitoring of even small single-phase motors with a no-load
supply current below 0.5 A
•
Simple determination of threshold values by the direct
collection of measured variables on motor loading
•
Range monitoring and active current measurement enable
detection of cable breaks between control cabinets and
motors, as well as phase failures
•
Power factor
and/or
I
res
(active current) can be selected as
the measurement principle
•
Width 22.5 mm
•
Display and transmission of actual value and status messages
to controller
•
All versions with removable terminals
•
All versions with screw or spring-type terminals
■
Application
•
No-load monitoring and load shedding, such as in the event
of a V-belt tear
•
Underload monitoring in the low performance range,
e.g. in the event of pump no-load operation
•
Monitoring of overload, e.g. due to a dirty filter system
•
Power factor monitoring in networks for control of compensa-
tion equipment
•
Broken cable between control cabinet and motor
■
Selection and ordering data
•
For monitoring the power factor
and the active current
I
res
•
Suitable for single- and three-phase currents
•
Adjustable via IO-Link and locally, with illuminated LCD
•
Power supply with 24 V DC via IO-Link or external auxiliary
voltage
•
Overshoot, undershoot or range monitoring adjustable
•
Upper and lower limit values can be adjusted separately
•
Permanent display of actual value and tripping state
•
1 CO contact each for undershoot and overshoot,
1 semiconductor output (in SIO mode)
1)
Absolute limit values.
For accessories see page 5/53.
For AC active currents
I
res
> 10 A it is possible to use commer-
cially available current transformers, e.g. Siemens 4NC current
converter, as accessories, see Catalog LV 10 "Low-Voltage
Power Distribution and Electrical Installation Technology".
Measuring range
Voltage
range of the
measuring
voltage
1)
Hysteresis
ON-delay time
adjustable
onDel
Tripping delay
time adjustable
U
▲
Del/
U
▼
Del,
▲
Del/
▼
Del
Screw
terminals
Spring-type
terminals
For power
factor
For active
current
I
res
50/60 Hz AC
Adjustable
for power
factor
Adjustable
for active
current
I
res
P.f.
A
V
P.f.
A
s
s
Article No.
Article No.
Monitoring of power factor
and active current for overshooting and undershooting
0.1 ... 0.99
0.2 ... 10
90 ... 690
0.1 ... 0.2
0.1 ... 3
0 ... 999.9
0 ... 999.9
3UG4841-1CA40
3UG4841-2CA40
3UG4841-1CA40
3UG4841-2CA40
© Siemens AG 2014