DATA S H E E T
Thermal Cutoff SEFUSE
TM
SM/G SERIES
FUSIBLE ALLOY THERMAL SENSITIVE TYPE,
0.5 AMPERES (250 Va.c.) and 3 and 5 AMPERES (50 Vd.c.) Rated Current
The NEC's SEFUSE (SM/G series) is a small, solid and reliable thermal cutoff that can be used under 0.5 A / 250
Vac. 3 and 5 ampere / 50 Vdc. electrical rating type, added to the product line-up lately, is also available. It
protects home appliances and industrial equipment from fire and accident by opening of electrical circuit if it
senses an abnormal temperature rise.
FEATURES
™
Approved by UL (USA), CSA (Canada), VDE (Germany), BEAB (UK) and MITI (Japan)
™
Very small
™
Conpact, durable and veliable by hermetic seal structure.
™
Excellent sensitive to abnormal temperature rise and high accuracy in operation.
™
Stable characteristics in a long-term.
™
Capable of opening at a cutoff current of AC 0.5 amperes and DC 3 and 5 amperes.
™
One shot operation.
APPLICATIONS
Transformers
Motors
Battery packs
Electric home appliances
Electric Industrial equipments,
Office automation equipments, etc.
OUTLINE DIMENSIONS (Unit : mm)
φ
0.53
φ
1.6
φ
0.53
40(70)
5.0
85(145)
40(70)
Note:
Dimensions in parentheses are for long lead devices.
The information in this document is subject to change without notice.
Document No. EM0255EJ5V0DS00 (5th edition)
Date Published March 1998 M
Printed in Japan
©
1992 (1997)
SM/G SERIES
MARKING
SM/G SERIES
MITI
approved mark
SEFUSE
110 GO
Brand name
Part number
(First two letters “SM” are omitted)
Rated functioning temperature
Rated voltage
∗∗
∗
Production control No.
Rated current
∗∗
Tf 115˚C
0.5 A 250V ~
∗
Designation of Production Control No.
(example)
8 1 0
Sub-Lot No.
Production month (1 to 9 as Jan. to Sep. and X, Y, Z as Oct., Nov. and Dec.)
Production year (last figure of A. D.)
∗∗
The marking of electrical ratinga is only the AC ratings and the DC ratings is not indicated.
TYPE NAME DESIGNATION
SM
110
G 0
Lead Length (0 : standard lead type, 1 : long lead type)
Series Name (SM/G series)
Operating Temperature
Type Name (SM type)
STANDARD RATINGS
(AC Electrical Ratings)
1)
Part
Number
SM095G0
SM110G0
SM126G0
SM130G0
SM145G0
SM134G0
Rated
Operating
Functioning
Temperature
Temperature
100 ˚C
115 ˚C
131 ˚C
135 ˚C
150 ˚C
139 ˚C
95
+5
˚C
–0
110±2 ˚C
126±2 ˚C
130±2 ˚C
145±2 ˚C
134
+3
˚C
–2
T
H
T
h
T
C
65 ˚C
80 ˚C
96 ˚C
100 ˚C
115 ˚C
104 ˚C
T
M
T
m
115 ˚C
125 ˚C
140 ˚C
145 ˚C
155 ˚C
200 ˚C
Rated
Current
Rated
Voltage
Safety Standard
UL
CSA
VDE
6778.2
–1171
–0003
BEAB
33–466
33–472
C0743
33–467
33–468
33–467
0.5 Aac
(res.)
250 Vac
(res.)
E71747 LR52330
4)
( )
6778.2
–4510
–1005
2)
(DC Electrical Ratings)
1)
Part
Number
SM095G0
SM110G0
SM126G0
SM130G0
SM145G0
SM134G0
Notes 1) :
2) :
3) :
4) :
2
Rated
Operating
Functioning
Temperature
Temperature
100 ˚C
115 ˚C
131 ˚C
135 ˚C
150 ˚C
139 ˚C
95
+5
˚C
–0
110±2 ˚C
126±2 ˚C
130±2 ˚C
145±2 ˚C
134
+3
–2
˚C
T
H
T
h
T
C
65 ˚C
80 ˚C
96 ˚C
100 ˚C
115 ˚C
104 ˚C
T
M
T
m
115 ˚C
125 ˚C
140 ˚C
145 ˚C
155 ˚C
200 ˚C
Rated
Current
3 Adc
Rated
Voltage
Safety Standard
UL
CSA
VDE
BEAB
3)
5 Adc
50 Vdc
E71747
2)
The type names are for standard lead. When long lead type is required, change the last number “0” to “1”.
Under application
There is no regulation about d.c. electrical ratings in the Electrical Appliance and Material Control Low of Japan.
The VDE recognized file number had been changed in February 1998. The number in parentheses are previous
file number.
SM/G SERIES
Definition of Terms
q
Rated Functioning Temperature
Rated functioning temperature is the operating temperature of the thermal cutoff, measured using the method
specified in the safety standard. In Electrical Appliance and Material Control Law of Japan, case operation
should be within the specified operating temperature range of
±
7 ˚C. In standards that comply with the IEC
standard (such as UL, CSA, VDE, BEAB), it is called the rated functioning temperature, and should operate
within the prescribed temperature range of +0/–10 ˚C.
It is represented by the symbol T
F
in the UL standard, and by the symbol Tf in the CSA, VDE and BEAB
standards.
In SEFUSE, a temperature that complies with both standards is set as the rated functioning temperature, and
is indicated on the body of the thermal cutoff.
q
Operating Temperature
Operating temperature is the operating temperature range when the thermal cutoff is made to operate inside
a constant temperature oven whose temperature is raised at the rate of 1 ˚C/min. while a detection current of
100 mA or lower is applied.
The operating temperature is a standard set by NEC and is not specified by a safety standard.
q
T
H
, Th. Tc (Holding Temperature)
Holding temperature is the maximum temperature at which, when applying a rated current to the thermal
cutoff, the state of conductivity is not changed during 168 hours.
It is represented by the symbol T
H
in the UL standard, Th in the CSA standard, and Tc in the VDE and BEAB
standards.
q
T
M
, Tm (Maximum Temperature Limit)
Maximum temperature limit is the maximum temperature for which conductivity does not occur again after
thermal cutoffs operation.
It is represented by the symbol T
M
in the UL standard and by Tm in the CSA, VDE and BEAB standards.
q
Rated Current
Maximum alternating current that can pass through the thermal cutoff and that the thermal cutoffs can cut off
the circuit in safety and reliability.
q
Rated Voltage
Maximum circuit voltage that the thermal cutoffs can cut off the circuit in safety and reliability.
3
SM/G SERIES
Performance Data
SM/G Series
Temperature Rise
SM095G0
Response Time
10
Temperature Rise (˚C)
SM110G0
SM126G0
SM130G0
SM134G0
5
SM145G0
0
1
2
3
4
5
Pass-through Current (A)
,,,,,,
,, ,
,, ,, , ,
,,,,,,,,,,
,
,, ,,,,
, ,,
,,, ,, , ,
,, , , ,,
, ,
30
SM095G0
SM110G0
SM126G0
SM130G0
SM134G0
SM145G0
Time for opening after immersion
into oil (seconds)
20
10
0
10
20
30
Temperature Difference (˚C)
(oil temp. minus operating temp.)
Initial Characteristics
146
SM145G0
High Temperature Storage Test
5.0
4.0
3.0
6.0
5.0
4.0
6.0
5.0
4.0
6.0
5.0
4.0
6.0
5.0
4.0
13.0
11.0
9.0
Part
Number
10
6
10
5
10
4
10
6
10
5
10
4
10
6
10
5
10
4
10
6
10
5
10
4
10
6
10
5
10
4
10
6
10
5
10
4
Insulation
3.0
2.0
1.0
3.0
2.0
1.0
3.0
2.0
1.0
3.0
2.0
1.0
3.0
2.0
1.0
3.0
2.0
1.0
+
5
SM145G0
@125˚C
145
144
135
0
–
5
+
5
@115˚C
SM134G0
134
133
131
SM134G0
0
–
5
+
5
@110˚C
SM130G0
130
129
127
SM130G0
0
–
5
+
5
@106˚C
SM126G0
126
125
112
SM126G0
0
–
5
+
5
@90˚C
SM110G0
111
110
99
SM110G0
0
–
5
+
5
@75˚C
SM095G0
98
97
SM095G0
0
–
5
Change of
Operating
Temperature
(˚C)
Part
Number
Withstand Voltage
Operating
Internal
Resistance after
after Operation
Temperature
Resistance
Operation
(kV)
(˚C)
(mΩ/25 mm)
(MΩ)
0 10
100
1,000
10,000
Time (Hours)
4
SM/G SERIES
Cautions
This section describes cautions designed to protect the performance of the thermal cutoff, Be sure to read and
fully understand these cautions.
To obtain full performance from the thermal cutoff, it is necessary for the customer to appropriately store
the thermal cutoff, design appropriate circuits for the application, and perform evaluations, mounting and
testing as necessary. Problems arising from the inappropriate execution of the above are the responsibility
of the customer, and NEC declines any and all responsibility.
Design Cautions
q
Do not use this device for any purpose other than as a thermal cutoff.
The thermal cutoff is designed to detect abnormal rises in temperature and break circuits if needed. It is not
a current fuse that cuts excess current. If used as a current fuse, the SEFUSE may malfunction.
q
Do not use this device in aerospace equipment, aeronautical equipment, nuclear reactor control systems, Iife
support equipment or systems, transportation machinery engine control or safety-related equipment.
This device is designed for use in household electric appliance, office automation equipment, audio and video
equipment, computer and communications equipment, test and measurement equipment, personal electronic
equipment and transportation equipment (excluding engine control).
q
The customer should select the proper thermal cutoff device, mounting location, and mounting method as
appropriate for each application.
Verify whether the chosen selections are appropriate by repeatedly testing the final design for thermal cutoff
under normal conditions as well as under predicted maximum abnormal conditions.
q
Make designs so that the temperature of the body of the thermal cutoff does not exceed the temperatures
shown in Table 1.
If, these temperatures are exceeded on a regular basis, the thermal cutoff may start operating only at tem-
peratures lower than the normal operating temperature. Malfunctions may also occur. Even if the thermal
cutoff's operating temperature is exceeded, it may malfunction.
Table 1. Recommended maximum body temperature on a reqular basis
Pass-through Current
Part Number
to 1 A
SM095G
SM110G
SM126G
SM130G
SM134G
SM145G
75˚C
90˚C
106˚C
110˚C
114˚C
125˚C
to 2 A
70˚C
85˚C
106˚C
110˚C
114˚C
125˚C
to 3 A
65˚C
85˚C
100˚C
105˚C
110˚C
120˚C
to 4 A
—
80˚C
95˚C
100˚C
105˚C
120˚C
to 5 A
—
75˚C
90˚C
95˚C
100˚C
115˚C
∗1)
:
The temperature does not means ambient temperature but surface temperature on
thermal cutoff.
∗2)
:
When a large current flows through a thermal cutoff, temperature difference occurs
between the case and the lead. Therefore, it is recommended to measure some points
on the thermal cutoff, and make design so that the highest temperature does not exceed
the temperature shown in Table 1.
5
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