Monitoring Relays
Tachometer
Type SM 155
• Tachometer relay
• Measuring ranges:
30 - 300 R.P.M.
200 - 2000 R.P.M.
1000 - 10000 R.P.M.
• Knob-adjustable set level
• Controlled by Namur/DIN 19234 sensor or metallic
contact
• Connection for moving-coil instrument
• 10 A SPDT output relay
• LED indication for relay ON
• AC or DC power supply
Product Description
SM155 monitors the actual
RPMs of a motor by a
Namur/DIN 19234 sensor or
a metallic contact.
Knob adjustable set level on
relative scale.
Ordering key
Housing
Function
Output
Type
Power upply
Measuring range
SM 155 230 10K
Type Selection
Plug
Circular
11 pins
Output Measuring range
SPDT
SPDT
SPDT
Supply: 24 VAC
Supply: 115 VAC
SM 155 115 300
SM 155 115 2K
SM 155 115 10K
Supply: 230 VAC
SM 155 230 300
SM 155 230 2K
SM 155 230 10K
Supply: 24 VDC
SM 155 724 300
SM 155 724 2K
SM 155 724 10K
30 - 300 R.P.M.
SM 155 024 300
20 - 2000 R.P.M.
SM 155 024 2K
1000 - 10000 R.P.M.
SM 155 024 10K
Input Specifications
Input
Through terminals:
Metallic contact:
Namur sensor:
Measuring ranges
Types:
300:
2K:
10K:
Inversion
Short circuit current
Pins 5, 6
Pins 6, 7
Connection cable
Max resistance
Hysteresis
5, 6
6, 7
Output Specifications
Output
Instrument connection
Through pins
Full scale deflection
Internal resistance
Rated insulation voltage
Contact ratings
(AgCdO)
Resistive loads
AC 1
DC 1
Small inductive loads AC 11
DC 11
Mechanical life
Electrical life
Operating frequency
Dielectric strength
Dielectric voltage
SPDT relay
Connection for moving-coil
instrument
8, 9, pin 9 positive
1 mA
110
Ω
250 VAC
µ
10A, 250 VAC
1 A, 250 VDC
2.5 A, 230 VAC
5 A, 24 VDC
≥
30 x 10
6
operations
≥
2.5 x 10
5
operations
(at max load)
≤
7200 operations/h
≥
2 kVAC (rms)
30
to 300 R.P.M.
200 to 2000 R.P.M.
1000 to 10000 R.P.M.
Interconnecting pins 8, 11
5 mA
10 mA
Can be extended as desired
100
Ω
approx 3% of set value
Specifications are subject to change without notice (13.03.01)
1
SM 155
Supply Specifications
Power supply
Rated operational voltage
Through terminals 2, 10
024:
115:
230:
724:
Dielectric voltage
Transient protection
Rated operational power
AC models
DC models
Overvoltage cat. III
(IEC 60664, IEC 60038)
24 VAC ± 15%, 45 to 65 Hz
115 VAC ± 15%, 45 to 65 Hz
230 VAC ± 15%, 45 to 65 Hz
24 VDC ± 15%
2 kV
> 3kV
4 VA
2W
General Specifications
Reaction time
Time between 2 pulses at
the set value of the poten-
tiometer
± 3%
LED, green
LED, red
IP 20
-20 to +50°C
-50 to +85°C
35 x 80 x 83 mm
Approx. 200 g
Approx. 125 g
UL, CSA
Yes
Accuracy of measurement
Indication for
Power supply ON
Output relay ON
Environment
Degree of protection
Operating temperature
Storage temperature
Housing dimensions
Weight
AC power supply
DC power supply
Approvals
CE Marking
Mode of Operation/Level Setting
The relay is controlled by
mechanical triggering, e.g.
microswitch, reed relay, limit
switch etc. (examples 1 and
2), or by electronic trigger-
ing, e.g. inductive or capaci-
tive sensors (NAMUR/DIN
19234) (examples 3 and 4).
Examples 1 and 3
The relay operates when the
number of R.P.M. exceeds
the set value.
The relay releases when the
number of R.P.M. is less than
the set value. See hysteresis.
Example 2 and 4
By interconnecting pins 8
and 11 the relay function is
inverted, i.e. the relay releas-
es when the number of
R.P.M. exceeds the set
value.
The relay operates when the
number of R.P.M. is less than
the set value. See hysteresis.
Instrument connection
A moving-coil instrument
with a scale calibrated in
R.P.M. can be connected to
the SM 155. The instrument
has 1 mA full scale deflec-
tion.
The relay generates max. 8.2
V on the instrument termi-
nals (pins 8 and 9) across an
internal resistance of 8.2 kΩ
in the relay. The ideal internal
resistance of the instrument
is 110
Ω.
A deviation in the
internal resistance of ± 100
Ω
results in an error of ± 1%.
Level Setting
Knob adjustable on relative
scale
Wiring Diagrams
Ex. 1, 2 - Mechanic triggering with metallic contact
Ex. 3, 4 - Electr. trig. with NAMUR/DIN 19234 sensor
2
Specifications are subject to change without notice (13.03.01)