SF RELAYS
Flat type safety relays
FEATURES
1. Forced operation contacts
N.O. and N.C. side contacts are
connected through a card so that one
interacts with the other in movement. In
case of a contact welding, the other
keeps a min. 0.5mm .020inch contact
gap.
2. Separated chamber structure
N.O. and N.C. side contacts are put in
each own space surrounded with a card
and a body-separater. That prevents
short circuit between contacts, which is
caused by their springs welding or
damaged.
3. Contact arrangement of 3 Form A
1 Form B
Enables various forms of control circuit.
4. High breakdown voltage
High breakdown voltage 2,500 Vrms
(between contact sets/ between contact
and coil)
RoHS compliant
5. High sensitivity
Realizes thin shape and high sensitivity
(500mW nominal operating power) by
utilizing high-efficiency polarized
magnetic circuit with 4-gap balanced
armature.
6. Complies with safety standards
Standard products are UL, CSA, TÜV
and SEV certified. Conform to European
standards. TÜV certified. Complies with
SUVA European standard.
TYPICAL APPLICATIONS
1. Industrial equipment such as
presses and machine tools
2. Elevators and other kinds of
hoisting mechanisms, conveyor
equipment.
ORDERING INFORMATION
SF 3
Contact arrangement
3: 3 Form A 1 Form B
Nominal coil voltage
DC 5, 12, 24, 48, 60V
TYPES
Contact arrangement
3 Form A 1 Form B
Nominal coil voltage
5V DC
12V DC
24V DC
48V DC
60V DC
Part No.
SF3-DC5V
SF3-DC12V
SF3-DC24V
SF3-DC48V
SF3-DC60V
Standard packing: Carton: 20 pcs.; Case: 200 pcs.
RATING
1. Coil data
Contact
arrangement
Nominal coil
voltage
Pick-up voltage
(at 20°C 68°F)
Drop-out voltage
(at 20°C 68°F)
80%V or less of
nominal voltage
(Initial)
10%V or more of
nominal voltage
(Initial)
5V DC
3 Form A 1 Form B
12V DC
24V DC
48V DC
60V DC
Nominal coil current
[±10%]
(at 20°C 68°F)
100mA
Coil resistance
[±10%]
(at 20°C 68°F)
50Ω
41.7mA
20.8mA
10.4mA
8.3mA
288Ω
1,152Ω
4,608Ω
7,200Ω
–1–
Nominal operating
power
(at 20°C 68°F)
Max. applied
voltage
(at 20°C 68°F)
500mW
120%V of
nominal voltage
ASCTB118E 201408-T
SF
2. Specifications
Characteristics
Contact
Rating
Item
Arrangement
Contact resistance (Initial)
Contact material
Nominal switching capacity (resistive load)
Max. switching power (resistive load)
Max. switching voltage
Max. switching current
Nominal operating power
Min. switching capacity (Reference value)*1
Insulation resistance (Initial)
Breakdown voltage
(Initial)
Electrical
characteristics
Specifications
3 Form A 1 Form B
Max. 30 mΩ (By voltage drop 6 V DC 1A)
Au-flashed AgSnO2 type
6A 250V AC, 6A 30V DC
1,500VA 180W
250V AC, 30V DC
6A
500mW
100mA 5V DC
Min. 1,000MΩ (at 500V DC) Measurement at same location as “Breakdown voltage” section.
Between open contacts
Between contact sets
Between contact and coil
2,500 Vrms for 1min. (Detection current: 10mA)
2,500 Vrms for 1min. (Detection current: 10mA)
2,500 Vrms for 1min. (Detection current: 10mA)
Max. 45°C 113°F
(By resistive method, nominal voltage applied to the coil; contact carrying current: 6A)
—
Max. 30ms (Nominal voltage applied to the coil, excluding contact bounce time.)
Max. 15ms (Nominal voltage applied to the coil, excluding contact bounce time.)
(without diode)
Min. 294 m/s2 (Half-wave pulse of sine wave: 11 ms; detection time: 10μs)
Min. 980 m/s2 (Half-wave pulse of sine wave: 6 ms)
10 to 55 Hz at double amplitude of 2 mm (Detection time: 10μs)
10 to 55 Hz at double amplitude of 2 mm
Min. 107: (at 180 times/min.)
Min. 3×104 (at 20 times/min.)*2
Ambient temperature: –40°C to +70°C –40°F to +158°F
Humidity: 5 to 85% R.H. (Not freezing and condensing at low temperature)
180 times/min.
38g 1.34oz
Temperature rise (coil)
Surge breakdown voltage (between contact and coil)
Operate time
Release time
Functional
Destructive
Functional
Vibration resistance
Destructive
Mechanical
Electrical
Shock resistance
Mechanical
characteristics
Expected life
Conditions
Conditions for operation, transport and storage*3
Max. Operating speed
Unit weight
Notes: *1. This value can change due to the switching frequency, environmental conditions and desired reliability level, therefore it is recommended to check this with the
actual load.
*2. More than 105 operations when applying the nominal switching capacity to one side of contact pairs of each Form A contact and Form B contact
*3. The upper limit of the ambient temperature is the maximum temperature that can satisfy the coil temperature rise value. Refer to Usage, transport and storage
conditions in NOTES.
DIMENSIONS (mm inch)
The CAD data of the products with a
CAD Data
mark can be downloaded from: http://industrial.panasonic.com/ac/e/
External dimensions
CAD Data
Schematic (Bottom view)
5
6
7
8
9
10
11
12
1
16±0.5
.630±.020
2
0.5
.020
5.08
.200
12.7
.500
12.7
.500
12.7
.500
3.5±0.5
.138±.020
PC board pattern (Bottom view)
53.3±0.5
2.098±.020
25.0
.984
0.30
.012
5
6
7
0.48
.019
8
2.54
.100
1
12.7
.500
7.62
.300
10-1.4 dia. holes
10-.055 dia. holes
2.54
.100
2
9
10
11
1.0
.039
12
1.0
.039
General tolerance: ±0.3 ±.012
Tolerance: ±0.1 ±.004
SAFETY STANDARDS
UL/C-UL (Recognized)
File No.
Contact rating
E120782
6A 250V AC
TÜV (Certified)
File No.
968/EZ 312.01/09
Rating
6A 250V AC
SEV
File No.
12.0193
Contact rating
6A 250V AC
* CSA standard: certified by C-UL
–2–
ASCTB118E 201408-T
SF
SAFETY STRUCTURE OF SF RELAYS
scenario, relay breakdown (coil rupture,
faulty operation, faulty return, and fatigue
and breakage of the operating spring and
return spring), and even in the event of
end of life.
(unforeseen externally caused circuit or
device breakdowns, end of life incidents,
and noise, surge, and environmental
influences) owing to contact welding,
spring fusion or, in the worst-case
This SF relay design ensures that
subsequent operations shut down and
can automatically return to a safe state
when the SF relay suffers overloading
and other circuit abnormalities
Structure
Operation
Min. 0.5 mm .020 inch
Even when one contact is welded closed, the other
maintains a gap of greater than 0.5 mm .020 inch.
Contact a
1. Forced operation method
(3 Form A 1 Form B types)
In the diagram on the left, the lower contact “b” have
welded but the upper contact “a” maintain at a gap of
greater than 0.5 mm .020 inch.
Subsequent contact movement is suspended and the
weld can be detected
Card
Contact b
Weld
The two contacts “a” and “b” are coupled with the same card. The operation
of each contact is regulated by the movement of the other contact.
Case separator
1
Card
Prevents shorting and fusing of springs and spring
failure owing to short-circuit current.
Contact a
2. Separate chamber method
(3 Form A 1 Form B types)
2
Body
separator
As shown on the diagram on the left, even if the
operating springs numbered 1 and 2 there is no
shorting between “a” and “b” contacts.
Contact b
In independent chambers, the contacts “a” and “b” are kept apart by a body/
case separator or by the card itself.
3. 3 Form A 1 Form B contact
Independent COM enables differing pole circuit
Structure with independent COM contact of (3 Form A 1 Form B), contacts. configurations. This makes it possible to design
various kinds of control circuits and safety circuits.
Form “b” Contact Weld
If the form “b” contact (No. 3) welds, the armature becomes non-operational, the contact gaps at the three form “a” contacts are
maintained at greater than 0.5 mm .020 inch. Reliable isolation is thus ensured.
No.4
No.1
No.3
No.2
Non-energized
No.4
No.1
No.3
No.2
If the No. 3 contact welds.
Each of the three form “a” contacts (No. 1, 2, and 4)
maintain a gap of greater than 0.5 mm .020 inch.
Energized (when no. 3 contact is welded)
Because the welded contact spring is attached to the
card, the armature has become inoperative.
Form “a” Contact Weld
When the form “a” contacts (No. 1, 2, or 4) weld, the armature remains in a non-returned state and the contact gap at the single form
“b” contact is maintained at greater than 0.5 mm .020 inch. Reliable isolation is thus ensured.
No.4
No.1
No.4
No.1
If the No. 2 contact welds.
The single form “b” contact (No. 3) maintains a gap of
greater than 0.5 mm .020 inch.
No.3
No.2
Energized
No.3
No.2
Non-energized (when no. 2 contact is welded)
–3–
ASCTB118E 201408-T
SF
Contact Operation Table
No.4
No.1
The table below shows the state of the other contacts when the current through
the welded form “a” contact is 0 V and the rated voltage is applied through the
form “b” contact.
State of other contacts
2
3
4
>0.5
>0.5
>0.5
>0.5
>0.5
>0.5
1
No.3
Contact No.
Terminal No.
No.2
No.1
11–12
No.2
7–8
No.3
5–6
No.4
9–10
Welded
terminal
No.
1
2
3
4
>0.5: contact gap is kept at
min. 0.5 mm .020 inch
Empty cells: either closed or open
* Contact gaps are shown at the initial state.
If the contacts change state owing to loading/breaking
it is necessary to check the actual loading.
NOTES
1. For cautions for use, please read
“General Application Guidelines”.
–4–
ASCTB118E 201408-T
GUIDELINES FOR POWER, HIGH-CAPACITY DC CUT OFF AND SAFETY RELAYS USAGE
For cautions for use, please read “GUIDELINES FOR RELAY USAGE”.
https://industrial.panasonic.com/ac/e/control/relay/cautions_use/index.jsp
Precautions for Coil Input
Long term current carrying
A circuit that will be carrying a current continuously for long periods
without relay switching operation. (circuits for emergency lamps, alarm
devices and error inspection that, for example, revert only during
malfunction and output warnings with form B contacts) Continuous,
long-term current to the coil will facilitate deterioration of coil insulation
and characteristics due to heating of the coil itself.
For circuits such as these, please use a magnetic-hold type latching
relay. If you need to use a single stable relay, use a sealed type relay
that is not easily affected by ambient conditions and make a failsafe
circuit design that considers the possibility of contact failure or
disconnection.
DC Coil operating power
Steady state DC current should be applied to the coil. The wave form
should be rectangular. If it includes ripple, the ripple factor should be
less than 5%.
However, please check with the actual circuit since the electrical
characteristics may vary. The rated coil voltage should be applied to
the coil and the set/reset pulse time of latching type relay differs for
each relays, please refer to the relay's individual specifications.
Maximum allowable voltage and temperature rise
Proper usage requires that the rated coil voltage be impressed on the
coil. Note, however, that if a voltage greater than or equal to the
maximum continuous voltage is impressed on the coil, the coil may
burn or its layers short due to the temperature rise. Furthermore, do
not exceed the usable ambient temperature range listed in the catalog.
perate voltage change due to coil temperature rise
O
(Hot start)
In DC relays, after continuous passage of current in the coil, if the
current is turned OFF, then immediately turned ON again, due to the
temperature rise in the coil, the pick-up voltage will become somewhat
higher. Also, it will be the same as using it in a higher temperature
atmosphere. The resistance/temperature relationship for copper wire
is about 0.4% for 1°C, and with this ratio the coil resistance increases.
That is, in order to operate of the relay, it is necessary that the voltage
be higher than the pick-up voltage and the pick-up voltage rises in
accordance with the increase in the resistance value. However, for
some polarized relays, this rate of change is considerably smaller.
Coil connection
When connecting coils of polarized relays, please check coil polarity
(+,-) at the internal connection diagram (Schematic). If any wrong
connection is made, it may cause unexpected malfunction, like
abnormal heat, fire and so on, and circuit do not work. Avoid
impressing voltages to the set coil and reset coil at the same time.
Ambient Environment
●Usage, Transport, and Storage Conditions
During usage, storage, or transportation, avoid locations subjected to
direct sunlight and maintain normal temperature, humidity and
pressure conditions.
●Temperature/Humidity/Pressure
When transporting or storing relays while they are tube packaged,
there are cases the temperature may differ from the allowable range.
In this case be sure to check the individual specifications.
Also allowable humidity level is influenced by temperature, please
check charts shown below and use relays within mentioned conditions.
(Allowable temperature values differ for each relays, please refer to
the relay's individual specifications.)
1) Temperature:
The tolerance temperature range differs for each relays, please
refer to the relay’s individual specifications
2) Humidity: 5 to 85 % RH
3) Pressure: 86 to 106 kPa
Humidity（％RH）
85
Allowable range
Avoid icing
when used at
temperatures
lower than 0°C
5
Avoid condensation when
used at temperatures higher
than 0°C
0
-40
Ambient temperature（℃）
85
Panasonic Corporation Electromechanical Control Business Division
industrial.panasonic.com/ac/e/
●Dew condensation
Condensation occurs when the ambient temperature drops suddenly
from a high temperature and humidity, or the relay is suddenly
transferred from a low ambient temperature to a high temperature and
humidity. Condensation causes the failures like insulation deterioration,
wire disconnection and rust etc.
Panasonic Corporation does not guarantee the failures caused by
condensation.
The heat conduction by the equipment may accelerate the cooling of
device itself, and the condensation may occur.
Please conduct product evaluations in the worst condition of the actual
usage. (Special attention should be paid when high temperature
heating parts are close to the device. Also please consider the
condensation may occur inside of the device.)
●Icing
Condensation or other moisture may freeze on relays when the
temperature become lower than 0°C.This icing causes the sticking of
movable portion, the operation delay and the contact conduction failure
etc. Panasonic Corporation does not guarantee the failures caused by
the icing.
The heat conduction by the equipment may accelerate the cooling of
relay itself and the icing may occur. Please conduct product
evaluations in the worst condition of the actual usage.
●Low temperature and low humidity
The plastic becomes brittle if the switch is exposed to a low
temperature, low humidity environment for long periods of time.
●High temperature and high humidity
Storage for extended periods of time (including transportation periods)
at high temperature or high humidity levels or in atmospheres with
organic gases or sulfide gases may cause a sulfide film or oxide film to
form on the surfaces of the contacts and/or it may interfere with the
functions. Check out the atmosphere in which the units are to be
stored and transported.
c Panasonic Corporation 2019
ASCTB412E 201906
GUIDELINES FOR POWER, HIGH-CAPACITY DC CUT OFF AND SAFETY RELAYS USAGE
●Package
In terms of the packing format used, make every effort to keep the
effects of moisture, organic gases and sulfide gases to the absolute
minimum.
●Silicon
When a source of silicone substances (silicone rubber, silicone oil,
silicone coating materials and silicone filling materials etc.) is used
around the relay, the silicone gas (low molecular siloxane etc.) may be
produced.
This silicone gas may penetrate into the inside of the relay. When the
relay is kept and used in this condition, silicone compound may adhere
to the relay contacts which may cause the contact failure. Do not use
any sources of silicone gas around the relay (Including plastic seal
types).
●NOx Generation
When relay is used in an atmosphere high in humidity to switch a load
which easily produces an arc, the NOx created by the arc and the
water absorbed from outside the relay combine to produce nitric acid.
This corrodes the internal metal parts and adversely affects operation.
Avoid use at an ambient humidity of 85%RH or higher (at 20°C). If use
at high humidity is unavoidable, please contact our sales
representative.
Others
Cleaning
1) Although the environmentally sealed type relay (plastic sealed type,
etc.) can be cleaned, avoid immersing the relay into cold liquid (such
as cleaning solvent) immediately after soldering. Doing so may
deteriorate the sealing performance.
2) Cleaning with the boiling method is recommended(The temperature
of cleaning liquid should be 40°C or lower ).
Avoid ultrasonic cleaning on relays. Use of ultrasonic cleaning may
cause breaks in the coil or slight sticking of the contacts due to
ultrasonic energy.
Please refer to "the latest product specifications"
when designing your product.
•Requests to customers:
https://industrial.panasonic.com/ac/e/salespolicies/
Panasonic Corporation Electromechanical Control Business Division
industrial.panasonic.com/ac/e/
c Panasonic Corporation 2019
ASCTB412E 201906
Please contact ..........
Electromechanical Control Business Division
1006, Oaza Kadoma, Kadoma-shi, Osaka 571-8506, Japan
industral.panasonic.com/ac/e/
©Panasonic Corporation 2019
ASCTB118E 201907
Specifications are subject to change without notice.
