Specifications are subject to change without notice (13.03.01) 1
Plug Output Centre frequency Bandwidth Supply: 24 VAC Supply: 115 VAC Supply: 230 VAC
Circular SPDT 50 Hz 6 Hz SF 110 024 50/6 SF 110 115 50/6 SF 110 230 50/6
50 Hz 10 Hz SF 110 024 50/10 SF 110 115 50/10 SF 110 230 50/10
50 Hz 1, 3, 5 Hz SF 125 024 50/5 SF 125 115 50/5 SF 125 230 50/5
50 Hz 2, 4, 6 Hz SF 125 024 50/6 SF 125 115 50/6 SF 125 230 50/6
60 Hz 6 Hz SF 110 024 60/6 SF 110 115 60/6 SF 110 230 60/6
60 Hz 10 Hz SF 110 024 60/10 SF 110 115 60/10 SF 110 230 60/10
60 Hz 1, 3, 5 Hz SF 125 024 60/5 SF 125 115 60/5 SF 125 230 60/5
60 Hz 2, 4, 6 Hz SF 125 024 60/6 SF 125 115 60/6 SF 125 230 60/6
Monitoring Relays
Product Description
1-phase plug-in frequency
control relays with fixed as
well as adjustable bandwidth.
• Frequency control relay
• Fixed bandwidth, 6 or 10 Hz (SF 110) or
knob-adjustable bandwidth (SF 125)
• Quartz-controlled digital circuit (SF 125)
• Centre frequency: 50 or 60 Hz
• Output: 10 A SPDT relay
• Plug-in type module
• S-housing
• LED-indication for output ON
• AC power supply, 50 or 60 Hz
Ordering Key
Housing
Function
Output
Type
Power supply
Centre frequency
Bandwidth
Type Selection
Input Specifications
Input
Pin 2 & 10 Supply voltage
measures on own supply
Centre frequency 50 or 60 Hz
Bandwidth Fixed (SF 110):
6 or 10 Hz ± 0.5 Hz
Adjust. (SF 125):
1, 3, 5 Hz ± 0.02 Hz or
2, 4, 6 Hz ± 0.02 Hz
Power supply AC types Overvoltage cat. III (IEC 60664)
Rated operational voltage (IEC 60038)
Through pins 2 & 6 024 24 VAC ± 15%, 50 or 60 Hz
115
115 VAC ± 15%, 50 or 60 Hz
230
230 VAC ± 15%, 50 or 60 Hz
Voltage interruption ≤40 ms
Dielectric voltage
2 kVAC (rms) (supply/elect.)
Rated impulse withstand volt. 4 kV (1.2/50 µs) (line/neutral,
line/line), direct connection
to electronics
Rated operational power
AC supply 2.5 VA
Often used in connection with
generator equipment.
1-Phase Frequency Control
Types SF 110, SF 125
Supply Specifications
SF 110 024 50/6
2Specifications are subject to change without notice
SF 110, SF 125
Output SPDT relay
Rated insulation voltage 250 VAC (rms)
(cont./elect.)
Contact ratings (AgCdO) µ (micro gap)
Resistive loads AC 1 10 A/250 VAC (2500 VA)
DC 1 1 A/250 VDC (250 W)
or 10 A/25 VDC (250 W)
Small inductive loads AC 15 2.5 A/230 VAC
DC 13 5 A/24 VDC
Mechanical life ≥30 x 106operations
Electrical life AC 1 ≥2.5 x 105operations
(at max. load)
Operating frequency ≤7200 operations/h
Dielectric strength
Dielectric voltage
≥2.0 kVAC (rms) (cont./elect.)
Rated impulse withstand volt. 4 kV (1.2/50 µs) (cont./elect.)
(IEC 60664)
Reaction time SF 110: Relay operates: τ= 0.1 s
Relay releases: τ= 1 s
SF 125: max. 2.5 s
Indication for
Output ON LED, red
Environment (IEC 60947-1)
Degree of protection IP 20 B (IEC 60529)
Pollution degree 2 (IEC 60664)
Operating temperature -20° to +50°C (-4° to +122°F)
Storage temperature -
50° to +85°C (-58° to +185°F)
Weight 200 g
Approvals UL, CSA
CE Marking Yes
Range Setting
Bandwidth setting (SF 125)
The bandwidth is set by built-
in potentiometer at the front
of the housing.
Hysteresis
SF 110: < 1% of centre fre-
quency.
Mode of Operation
SF 110
The relay monitors that the
frequency of the power sup-
ply - 50 or 60 Hz nominally - is
kept within a fixed tolerance.
The tolerance has a value of
± 3 Hz (± 5 Hz), which equals a
fixed bandwidth of 6 Hz (10 Hz).
As long as the frequency of
the power supply is kept with-
in the limits, e.g. 47 to 53 Hz,
± 0.5 Hz, the relay will be in
operating position, otherwise
it will release.
SF 125
The relay monitors that the
frequency of the power sup-
ply - 50 or 60 Hz nominally - is
kept within certain prese-
lected tolerances.
The bandwidth, which is set
on the potentiometer at the
front of the relay, is 1, 3, 5 or
2, 4, 6 Hz, equaling the below
tolerances:
Frequency Tolerance
1 Hz ± 0.5 Hz
3 Hz ± 1.5 Hz
5 Hz ± 2.5 Hz
2 Hz ± 1 Hz
4 Hz ± 2 Hz
6 Hz ± 3 Hz
As long as the frequency of
the power supply is kept
within the limits, e.g. 49 to 51
Hz, ± 0.01 Hz, the relay will be
in operating position.
The relay responds within 1 s.
The delay is due to the fact
that the measuring principle is
a digital counting of the half
cycles on a quartz-controlled
base time of 1 s.
Wiring Diagram
Power supply
SF 110, SF 125
Operation Diagram
0.5 - 1.5 - 2.5 Hz
fc - { 1 - 2 - 3 Hz
0.5 - 1.5 - 2.5 Hz
fc - { 1 - 2 - 3 Hz
Centre frequency (fc)
Relay ON
Power supply
Output Specifications General Specifications
