VibroSens 401 en - SCHMIDT Technology GmbH

SCHMIDT®
VibroSens 401
Operating Instructions
SCHMIDT® Vibration Control
VibroSens 401
Operating Instructions
1
Important information............................................................. 3
2
Use .......................................................................................... 4
3
Description of functions.......................................................... 5
4
Installation ............................................................................ 10
5
Electrical connections ........................................................... 12
6
Start-up.................................................................................. 14
7
Help with setting................................................................... 17
8
Technical data ....................................................................... 20
9
Dimensions ........................................................................... 21
10
Konformitätserklärung ......................................................... 22
Impressum:
Copyright 2004 SCHMIDT Technology
All rights reserved.
Printed in Germany.
Edition and modification date:
Version 1.3 dt. Juni 2004
Valid for equipment with year of manufacture from 02/2003
2
1 Important information
Before starting the device, these operating instructions are
to be read through completely and carefully heeded.
Failure to heed or adhere to these operating instructions can
result in claims on manufacturer’s liability becoming null and
void for damages ensuing therefrom.
Manual action of any manner on the device—with the exception of proper procedures and those described in these operating instructions—lead to forfeit of guarantee and exclusion from liability.
The device is solely intended for the usage as described below (see chapter 2). It is particularly not intended for the direct or indirect protection of persons.
SCHMIDT Technology assumes no liability whatsoever as
regards suitability for some specific purpose and assumes
no liability for errors found in this instruction manual, or for
coincidental or subsequent damages related to shipment,
capacity or use of this device.
The guarantee is effective for 6 months as of delivery and
covers material and workmanship defects. Within this time,
SCHMIDT Technology can either repair a device proved defective, or replace it with a device of equivalent value.
3
2 Use
The Schmidt VibroSens 401 Vibration Control is conceived
for use on machines, aggregates and single driving mechanism parts as well as general sub-assemblies and machine
components for the purpose of monitoring mechanical vibrations in accordance with DIN ISO 10816.
The device measures and assesses the effective vibration
speed (vibration amplitude) arising at the selected installation site. When a pre-set threshold value is exceeded, a relay on the device switches.
Externally installed switch functions can be tripped via the
corresponding switch outlets, like, f.i., an emergency-off for
the machine.
The momentary vibration amplitude can be registered over
an analogue outlet. This makes possible a continuous, permanent monitoring and recognition of the trend of the machine’s operating condition.
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3
Description of functions
3.1 Structure of the device
Fig. 1 shows the essential components of the VibroSens
401.
(1) Potentiometer for setting the vibration threshold Vthreshold
(2) Potentiometer for setting the vibration threshold Vthreshold
(3) Digital switch for setting the switch delay time Tthreshold
(4) Relay-change-over contact, floating 24 V/1 A
(5) Casing
(6) Attachment plate, electrically insulating
(7) Attachment borehole
(8) Casing cover plate
Fig. 1: Structure of the device
Fig. 1:equipment configuration
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3.2 Monitoring function
The Schmidt VibroSens 401Vibration Control registers and
evaluates the effective vibration speed in accordance with
ISO 2372/VDI 2056.
Alarm condtion:
The relay (4) (Fig. 1) signals a deviation from the normal operating condition of the monitored object, if the vibration amplitude Veff has exceeded the pre-set switch threshold Vthreshold for a pre-set minimum period of time Tthreshold.
Sensitivity of response:
If temporarily increased vibration amplitudes are expected in
the range of normal operating conditions, switching of the
relay can be suppressed by means of the switch delay time
Tthreshold. Switching behavior is portrayed in detail in the time
sequence diagram (Fig. 2). If the switch threshold Vthreshold is
exceeded for a silent period of T > Tthreshold, the relay
switches for a prescribed and fixed default switch time of 2 s.
If the silent period is T < Tthreshold, the relay does not respond.
Switch logic:
The switch conditions of the relay (4) are portrayed in Table
1 according to operating condition and vibration amplitude.
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Fig. 2: Time sequence diagram
Fig. 3: Relay switch logic
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Interrupting the voltage supply:
As the control coil of the relay is energized under normal operating conditions for the device, the relay drops out and
goes into alarm condition when the voltage supply is interrupted. Power failure or a wire-break in the supply circuit can
clearly be recognized.
Line monitoring:
Since the switch contact (pi/gr) is closed in normal operating
conditions (comp. Table 1), wire-break can be recognized in
the switch voltage circuit. The time-dynamic switch logic furthermore makes possible a differentiation between alarm
(switch time 2 s) and power failure or wire-break (switch time
permanent).
3.3 Method of measurement
The principle structure of the VibroSens 401 is represented
in the functional diagram (Fig. 3). The vibration amplitude is
registered with a piezoelectric acceleration sensor (1). The
sensor signal which is proportional to the acceleration is filtered by a pre-amplifier (2) with a frequency band pass (3)
and in step (4) integrated in real-time with a subsequent effective value formation (5).
The relay (8) is operated and switched by the comparator
step (6) with an adjustable switch threshold and the switch
delay link (7) as soon as the vibration level Veff has exceeded the switch threshold Vthreshold longer than the switch
delay time Tthreshold.
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Fig. 4: Block diagram VibroSens 401
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4
Installation
When installing, make sure that the signal direction given on
the device coincides as much as possible with the main actual signal direction of the surface of attachment. Only in this
way can maximum response sensitivity of the Vibration Control and sure recognition of the vibration condition be
achieved.
(1) The signal direction of the built-in vibration sensor is
marked (pictogram) on the device’s name plate (Fig. 5).
There are two different models:
Code No.
300386-1
300386-2
Signal direction
Pictogram
Parallel to surface of attachment
Vertical to surface of attachment
Fig. 5: Marking of the built-in vibration sensor on the device’s
name plate
Establish a flat-surface non-power lock to the object
to be measured!
Attach the device preferably to a smooth surface.
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Avoid contact resonance!
Screw in two M6 x 16 fixing bolts through both fixing holes of the mounting plate in the appropriate threaded boreholes in the object to be measured. It is best to tighten
the bolts evenly with a torque wrench.
Suppress wire vibrations!
Lay the connection cable along the surface of the object
and attach firmly with clamps or the like.
Avoid an earth short circuit with the object to be
measured!
The mounting plate of the Vibration Control is made of a
stable structured, non-electrically conductive material,
which results in the device’s mounting being electrically
insulated from the object to be measured.
In order to avoid extended spatial earth loops over the
connection cable and possible impairments to the device’s functions through external electromagnetic disturbances, it is mandatory that the electrical separation between device and object be observed.
»
The casing may not be in direct contact with
metal parts or other electrically conductive parts.
»
The distance between the device and the surrounding casing components must be great enough
to exclude contact due to vibrations, even during dynamic operations and in the event of resonance.
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5 Electrical connections
The Schmidt VibroSens 401Vibration Control has on the
casing a shielded, fixed, 6-core connection cable which
preferably is connected by the customer to a screw clamp
terminal strip. The shield connection (bk) and the earth connection (bl) are joined together electrically by the casing.
Make the electrical connections (7 x 0.34 mm2) in accordance with the name plate (see Fig. 4). The earth connection ⊥ (bl) serves both as reference potential for the power
outlet Veff (wh) and as negative connection for the voltage
supply system UB (br).
Tip:
The shielding effect of the connection cable can be impaired
by line-related disturbances depending on the disturbance
field configuration and the earth line in the immediate vicinity
of the mounting location. For optimum shielding it must be
decided from case to case whether to connect the shield at
the end of the cable (black line) in the external terminal
block, or not connect it at all.
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Function
Seizure
Anlalogueoutput
Value
Color code:
0 (4) ... 20 mA white
yellow
Switch relay
24 V / 1 A
grey
pink
Voltage
20 ... 30 V
brown
0V
blue
shielding
black
Fig. 6:Connecting VibroSens 401
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6
Start-up
The Vibration Control has been adjusted at the factory and
calibrated to the rated sensitivity of 0.4 mA/mms-1 at a sinus
frequency of 100 Hz.
After mounting and connection of the voltage supply system,
the device is ready for operation after a 10 s start delay period.
»
The device has not been set up with a defined presetting. To be sure of the desired monitoring function, the
operator must set the switch threshold Vthreshold and
switch delay time Tthreshold himself.
Device structure (Fig. 1) is to be heeded for setting the
switch parameters. Loosen the four screws on top of the
casing (5) and remove the casing cover plate (8).
Set and check the switch threshold Vthreshold.
- With a screw driver, set the switch threshold Vthreshold on the
potentiometer (1). The setting range is 2 … 50 mm/s.
a) Turning
the
set
increases the switch threshold
b) Turning
the
set
screw
decreases the switch threshold
- Check the set switch threshold.
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screw
clockwise:
counter-clockwise:
Check the set value at both measuring terminals (2) with a
voltmeter (digital). Use preferably laboratory wire clips for
connecting the measuring wires.
The voltage range of UP = 0,2 ... 5 V (direct current) is
equivalent to vthreshold = 2 ... 50 mm/s according to the relation:
v threshold = 10
Example:
»
mm/s
⋅ UP [V]
V
3.5 V test voltage corresponds to a switch
threshold of 35 mm/s
The test voltage at the measuring terminals (2)
must be tapped floating. Otherwise faulty voltages
occur, which result in a distortion of measurement
results.
Set the switch delay time Tthreshold.
The minimum delay time is set with the measurement electronics and is 2 s.
The effective switch delay time is yielded from the relationship
Tthreshold= SV+ 2 s.
SV is the set value in the range 0…10 s.
It is set with the slide button on the digital switch (3).
15
Slide button on digital switch (3)
a) in OFF position:
effective
additional switch delay is not
b) In ON position: set value SV = sum of the given numeri
cal values 1 s, 2 s, 3 s, 4 s
Example:
Set value
SV = 4 + 2 = 6 (s)
Fig. 7sequence diagram
Set value Tthreshold = SV + 2 = 4 + 2 + 2 = 8 (s)
The function of the switch delay time results from the time
sequence diagram (Fig. 2).
Tip:
Move the slide button on the digital switch (3), f.i., with the
blade of a screw driver.
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7
Help with setting
Setting the switch parameters requires as much knowledge
as possible about the vibration behavior of the object to be
monitored. Especially the threshold range between normal
conditions and possible faulty conditions should be known.
In general, vibration behavior is influenced by different factors. Among these factors are constructive design, site of
erection, characteristics of the foundation, operating conditions and the measurement site where the Vibration Control
is mounted. For this reason the switch threshold and switch
delay time must be individually set for each vibrational environment.
For orientation in assessing vibration behavior, the different
machines can be divided into four classes or groups of machines.
Class I/Group K:
Firmly connected driving mechanism parts of power machines and work machines. Electric motors up to 15 kW.
Class II/Group M:
Medium-size machines and electric motors from 15 to 75 kW
without a special foundation.
Firmly erected driving mechanism parts on special foundations up to ca. 300 kW.
Class III/Group G:
Large machines, power and work machines on raised, rigid
or heavy foundations.
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Class IV/Group T:
Large, power and work machines on low foundations, f.i.,
turbo aggregates with foundations designed following guidelines for light metal construction.
The vibration amplitude Veff is divided into discrete intervals
whose grades of assessment are allocated to the individual
machine classes or groups (Table 1). The set value of the
switch threshold Vthreshold should not exceed stage C (still allowed vibrational amplitude).
Tip:
These guides are for machines with circulating masses. Machine-specific settings must be made for machines with influences DIN ISO 10816 part 2 ... 6 as well as in the relevant, machine-specific guidelines.
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Vibration amplitude
Veff (mm/s)
Group K
Class I
Group M
Group G
Class II
Class III
Group T
Class IV
0,28
0,45
A
0,71
1,12
1,80
2,80
4,50
A
B
C
B
C
45,00
B
C
11,20
28,00
A
B
7,10
18,00
A
D
C
D
D
D
A = good
B = usable
C = still allowed
D = not allowed
Tabelle 1: Assessment of the vibrational intensity following DIN
ISO 10816-1
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8
Technical data
Measurement range (veff)
0 .. 50 mm/s
Frequency range
10 .. 1000 Hz (3 dB)
Switch threshold (vthreshold)
2 .. 50 mm/s
Switch delay (Tthreshold)
2 .. 12 s (typical +/-20%)
Start delay
10 s permanent
Switch outlet
Relay change-over contact
24 V /1 A potentialfrei
Switch function
Relay switches when switch
threshold is exceeded or
upon power failure. Automatic reset after 2 s upon
excess.
Analogue outlet (veff)
0 .. 20 mA or 4 .. 20 mA
Load resistance
300 Ω max.
Supply voltage
20 .. 30 VDC
Power consumption
45 mA max. (without load)
Operating temperature
-30 .. +80°C
Storage temperature
-30 .. +80°C
Type of enclosure
IP 65
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9
Dimensions
Bild 8: Dimensions of the housing
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10 Konformitätserklärung
22
23
24
Art.Nr.
SCHMIDT Technology GmbH
Feldbergstrasse 1
D-78112 St. Georgen
Phone +49 (0)7724/899-0
Fax +49 (0)7724/899-101
[email protected]
www.schmidttechnology.de