4
SF-RELAYS
Doub le contact
POLARISED, MONOSTABLE
SAFETY RELAY
mm inch
25.0
.984
2 Form A 2 Form B
4 Form A 4 Form B
16.5±0.5
.650±.020
53.3±0.3
2.098±.012
33±0.5
1.299±.020
16.5±0.5
.650±.020
53.3±0.3
2.098±.012
FEATURES
• High contact reliability
High contact reliability is achieved through
the use of a double contact.
• Forced operation contacts
(2 Form A 2 Form B)
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.
• Independent operation contacts
(4 Form A 4 Form B)
There are 4 points of forced operation
contacts.
Each pair of contacts is free from the main
armature and is independent from each
other. So if a N.O. pair of contacts are
welded, the other 3 N.O. contacts are not
effected (operate properly) That enables
to plan a circuit to detect welding or go
back to the beginning condition.
• Separated chamber structure (2 Form
A 2 Form B, 4 Form A 4 Form B)
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.
• High breakdown voltage 2,500 Vrms
between contacts and coil
• High sensitivity
Realizes thin shape and high sensitivity
(500 mW nominal operating power) by
utilizing high-efficiency polarized
magnetic circuit with 4-gap balanced
armature.
• Complies with safety standards
Standard products are UL, CSA, TÜV and
SEV certified. Comform to European
standards. TÜV certified (945/EL, 178/
88). Complies with SUVA European
standard.
SPECIFICATIONS
Contact
Coil
Remarks
* Specifications will vary with foreign standards certification ratings.
*
1
Measurement at same location as “Initial breakdown voltage” section
*
2
Detection current: 10mA
*
3
Excluding contact bounce time
*
4
Half-wave pulse of sine wave: 11ms; detection time: 10
µ
s
*
5
Half-wave pulse of sine wave: 6ms
*
6
Detection time: 10
µ
s
*
7
Refer to 6. Usage, transport and storage mentioned in NOTES
Characteristics
Contact arrangement 2 Form A
2 Form B 4 Form A
4 Form B
Initial contact resistance, max.
(By voltage drop 6 V DC 1 A) 30 m
Ω
Contact material Gold-flashed silver alloy
Rating
(resistive)
Nominal switching
capacity 6 A 250 V AC, 6 A 30 V DC
Max. switching power 1,500 VA, 180 W
Max. switching voltage 440 V AC, 30 V DC
Max. carrying current 6 A
Expected
life (min.
operations)
Mechanical (at 180 cpm) 10
7
Electrical (at 20 cpm) 10
5
Nominal operating power 500 mW
Contact arrangement 2 Form A
2 Form B 4 Form A
4 Form B
Max. operating speed 180 cpm (at nominal voltage)
Initial insulation resistance*
1
Min. 1,000 M
Ω
at 500 V DC
Initial
breakdown
voltage*
2
Between open contacts 1,300 Vrms
Between contact sets 2,500 Vrms
Between contact and coil 2,500 Vrms
Operate time*
3
(at nominal voltage) Approx. 17 ms Approx. 18 ms
Release time (without diode)*
3
(at nominal voltage) Approx. 7 ms Approx. 6 ms
Temperature rise (at nominal voltage)
(at 20°C) Max. 45°C
with nominal coil voltage and
at 6 A carry current
Shock resistance Functional*
4
Min. 294 m/s
2
{30 G}
Destructive*
5
Min. 980 m/s
2
{100 G}
Vibration resistance Functional*
6
10 to 55 Hz at double
amplitude of 2 mm
Destructive 10 to 55 Hz at double
amplitude of 2 mm
Conditions for operation,
transport and storage*
7
(Not
freezing and condensing at
low temperature)
Ambient
temp. –40°C to +70°C
–40°F to +158°F
Humidity 5 to 85% R.H.
Unit weight Approx.
38 g 1.34 oz Approx.
47 g 1.66 oz
(pending)
5
TYPES AND COIL DATA (at 20°C 68°F)
mm inch
DIMENSIONS
1. 2 Form A 2 Form B
Contact
arrangement Part No. Nominal
voltage , V DC Pick-up
voltage , VDC
(max.)
Drop-out
voltage , V DC
(min.) Coil resistance
Ω
(±10%)
Nominal
operating
current,
mA (±10%)
Nominal
operating
power, mW Max. allowab le
voltage , V DC
2 Form A
2 Form B
SF2D-DC5V 5 3.75 0.5 50 100 500 6
SF2D-DC12V 12 9 1.2 288 41.7 500 14.4
SF2D-DC24V 24 18 2.4 1.152 20.8 500 28.8
SF2D-DC48V 48 36 4.8 4.608 10.4 500 57.6
SF2D-DC60V 60 45 6.0 7.200 8.3 500 72
4 Form A
4 Form B
SF4D-DC5V 5 3.75 0.75 50 100 500 6
SF4D-DC12V 12 9 1.8 288 41.7 500 14.4
SF4D-DC24V 24 18 3.6 1.152 20.8 500 28.8
SF4D-DC48V 48 36 7.2 4.608 10.4 500 57.6
SF4D-DC60V 60 45 9.0 7.200 8.3 500 72
General tolerance: ±0.3 ±.012
12.7
.500
53.3±0.3
2.098±.012
12.7
.500
12.7
.500
5.08
.200
6587
109
1
2
1211
16±0.5
.630±.020
12.7
.500
3.0±0.5
.118±.020
0.5
.020
25.0
.984 7.62
.300
Schematic (Bottom view)
PC board pattern (Bottom view)
Tolerance: ±0.1 ±.004
5
1
2
678
9 101112
2.54
.100
2.54
.100
10-1.4 DIA. HOLES
10-.055 DIA. HOLES
2. 4 Form A 4 Form B
General tolerance: ±0.3 ±.012
12.7
.500
53.3±0.3
2.098±.012
12.7
.500
12.7
.500
5.08
.200
65
1817 2019
87
109
1413 1615
1
2
1211
16±0.5
.630±.020
12.7
.500
7.62
.300
7.62
.300
3.0±0.5
.118±.020
0.3
.012
33±0.5
1.299±.020
7.62
.300
Schematic (Bottom view)
PC board pattern (Bottom view)
Tolerance: ±0.1 ±.004
1
13
5
2
14
6
15
7
16
8
9
17
10
18
11
19
12
20
2.54
.100
2.54
.100
18-1.4 DIA. HOLES
18-.055 DIA. HOLES
ORDERING INFORMATION
Ex. SF 2 D DC 5 V
Contact arrangement Coil voltage
DC 5, 12, 24, 48, 60 V2: 2 Form A 2 Form B
4: 4 Form A 4 Form B
UL/CSA, TÜV, SEV approved type is standard
TYPICAL APPLICATIONS
• Industrial equipment such as presses and machine tools
6
REFERENCE DATA
1. Operate/release time (without diode)
Tested sample: SF2D-DC24V
Quantity: n = 20
2. Temperature rise
Tested sample: SF4D-DC24V
Quantity: n = 6
Coil applied voltage: 100%V, 120%V
Contact carry current: 6A
3. Ambient temperature characteristics
Tested sample: SF4D-DC12V
Quantity: n = 6
10
20
30
0
40
50
8070 10090 120 130110
Coil applied voltage, %V
Operate/release time, ms
Operate time
Release time
Min.
Max.
x
Min.
Max.
x
5
10
15
0
20
25
30
120100 110
Coil applied voltage, %V
Inside the coil
Contact
Temperature rise, °C
-40 -20 0 20 40 60 80
-50
100
50
-100
Drop-out voltage
Pick-up voltage
Ambient
temperature, °C
Rate of
change, %
7
THE OPERATION OF SF RELAYS (when contacts are welded)
SF relays work to maintain a normal operating state even when the contact welding occur by overloading or short-circuit
currents. It is easy to make weld detection circuits and safety circuits in the design to ensure safety even if contacts weld.
If the internal contacts (No. 2, 3, 6, and 7) weld of 4a4b type, the armature becomes non-operational and the contact gaps of each of
the f our f orm “a” contacts are maintained at greater than 0.5 mm .020 inch. Reliable isolation is thus ensured. The 2a2b type operates
in the same way.
Internal Contacts Weld
If the No. 2 contact welds.
Each of the four form “a” contacts (No. 1, 3, 5,
and 7) maintains a gap of greater than 0.5 mm
.020 inch.
No.1
No.2
No.3
No.4
No.8
No.7
No.6
No.5
Non-energized
No.1
No.2
No.3
No.4
No.8
No.7
No.6
No.5
Energized (when no. 2 contact is welded)
If the e xternal contacts (No. 1, 4, 5, and 8) weld of 4a4b type, gaps of g reater than 0.5 mm .020 inch are maintained between adjacent
contacts and the other contacts return by an non-energized.
External Contacts Weld
If the No. 1 contact welds.
The adjacent No. 2 contact maintains a gap of
greater than 0.5 mm .020 inch. The other
contacts, because the coil is not energized,
return to their normal retur n state; each of
form “a” contacts (No. 3, 5, and 7) maintains a
contact gap of greater than 0.5 mm .020 inch;
each of the form “b” contacts (No. 4, 6, and 8)
return to a closed state.
If external connections are made in series.
Even if one of the contacts welds, the other contacts
operate independently and the contact gaps are
maintained at greater than 0.5 mm .020 inch.
No.1
No.2
No.3
No.4
No.8
No.7
No.6
No.5
Energized
No.1
No.2
No.3
No.4
No.8
No.7
No.6
No.5
Non-energized (when no. 1 contact is welded)
Energized Contact gap
min 0.5 mm .020 inch
Weld
Non-energized
The table below shows the state of the other contacts. In case of form “a” contact weld the coil applied voltage is 0 V.
In case of form “b” contact weld the coil applied voltage is nominal.
Contact Operation Table
No.1
No.2
No.3
No.4
No.8
No.7
No.6
No.5
Contact No. No.1 No.2 No.3 No.4
Terminal No.
20–19 12–11 8–716–15
No.5 No.6 No.7 No.8
13–14 5–69–10 17–18
Note: Contact gaps are shown at the initial state.
If the contact transfer is caused by load switching, it is necessary to check the actual loading.
Contact No. State of other contacts
>0.5: contact gap
is kept at min. 0.5
mm .020 inch
≠
: contact closed
Empty cells: either
closed or open
Contact No. 1 2 3 4 5 6 7 8
Welded
contact
No.
1 >0.5 >0.5
≠
>0.5
≠
>0.5
≠
2 >0.5 >0.5 >0.5 >0.5
3 >0.5 >0.5 >0.5 >0.5
4
≠
>0.5 >0.5
≠
>0.5
≠
>0.5
5 >0.5
≠
>0.5
≠
>0.5 >0.5
≠
6 >0.5 >0.5 >0.5 >0.5
7 >0.5 >0.5 >0.5 >0.5
8
≠
>0.5
≠
>0.5
≠
>0.5 >0.5
NOTES
1. Coil operating power
Pure 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, check it with
the actual circuit since the characteristics
may be slightly different.
2. Coil connection
When connecting coils, ref er to the wiring
diagram to prevent mis-operation or
malfunction.
3. Cleaning
For automatic cleaning, the boiling
method is recommended. Avoid ultrasonic
cleaning which subjects the rela ys to high
frequency vibrations, which may cause
the contacts to stick.
It is recommended that a fluorinated
hydrocarbon or other alcoholic solvents
be used.
4. Soldering
We recommend the following soldering
conditions
1) Automatic soldering
1) Preheating: 100°C 212°F, max. 60 s
2) Soldering: 250°C 482°F, max. 5 s
5. Others
1) If the relay has been dropped, the
appearance and characteristics should
always be checked before use.
2) The cycle lifetime is defined under the
standard test condition specified in the
JIS* C 5442-1986 standard (temperature
15 to 35°C 59 to 95°F, humidity 25 to
85%). Chec k this with the real device as it
is affected by coil driving circuit, load type,
activation frequency, activation
phase,ambient conditions and other
factors.
Also, be especially careful of loads such
as those listed below.
(1) When used f or A C load-oper ating and
the operating phase is synchronous.
Rocking and fusing can easily occur due
to contact shifting.
(2) High-frequency load-operating
When high-frequency opening and
closing of the relay is performed with a
load that causes arcs at the contacts,
nitrogen and o xygen in the air is fused b y
the arc energy and HNO
3
is formed. This
can corrode metal materials.
Three countermeasures for these are
listed here.
1. Incorporate an arc-extinguishing
circuit.
2. Lower the operating frequency
3. Lower the ambient humidity
3) For secure operations, the voltage
applied to the coil should be nominal
voltage. In addition, please note that pick-
up and drop-out voltage will vary
according to the ambient temperature and
operation conditions.
4) Heat, smoke, and even a fire may occur
if the rela y is used in conditions outside of
the allowable ranges for the coil ratings,
contact ratings, operating cycle lifetime,
and other specifications. Theref ore, do
not use the relay if these ratings are
exceeded. Also, make sure that the relay
is wired correctly.
5) Incorrect wiring may cause unexpected
events or the generation of heat or flames.
6) Check the ambient conditions when
storing or transporting the relays and
de vices containing the relays . F reezing or
condensation may occur in the relay,
causing functional damage. Avoid
subjecting the relays to heavy loads, or
strong vibration and shocks.
6. Usage, transport and storage
conditions
1) Ambient temperature, humidity, and
atmospheric pressure during usage,
transport, and storage of the relay:
(1) Temperature:
–40 to +70°C –40 to +158°F
(2) Humidity: 5 to 85% RH
(Avoid freezing and condensation.)
The humidity range varies with the
temperature. Use within the range
indicated in the graph below.
(3) Atmospheric pressure: 86 to 106 kPa
Temperature and humidity range for
usage, transport, and storage:
2) Condensation
Condensation forms when there is a
sudden change in temperature under high
temperature and high humidity conditions.
Condensation will cause deterioration of
the relay insulation.
3) Freezing
Condensation or other moisture may
freeze on the relay when the
temperatures is low er than 0°C 32°F. This
causes problems such as sticking of
movable parts or operational time lags.
4) Low temperature, low humidity
environments
The plastic becomes brittle if the relay is
exposed to a low temperature, low
humidity environment for long periods of
time.
;
;;;
;;
;
;;
;;
;;;
;;
;;
;;;;;
;;
;;
;;;;;;;
;;
;;
;;;;;;;;
;;
;;
;;;;;;;;
;;
;
;;;;;;;;
;;
;;
;;;;;;
;;
;;
;;;;
;;
;;
;;
;;
;;;;
;;
Tolerance range
(Avoid
condensation when
used at temperatures
higher than 0°C 32°F)
(Avoid freezing when
used at temperatures
lower than 0°C 32°F)
85
5
–40
–40 0
+32 +70
+158
Temperature, °C °F
Humidity, %R.H.
2/19/2003 All Rights Reserved, © Copyright Matsushita Electric Works, Ltd.
Go To Online Catalog
