PTC thermistors for overcurrent
protection
Rods, uncoated, 500 V / 690 V
Series/Type:
B59404, B59405, B59406
Date:
March 2006
EPCOS AG 2006. Reproduction, publication and dissemination of this publication, enclosures hereto and the
information contained therein without EPCOS' prior express consent is prohibited.
Applications
Overcurrent and short-circuit protection
For high operating voltages
Features
Leaded rod-type thermistor
Low mounting height
RoHS-compatible
Delivery mode
Bulk
Dimensional drawing
Dimensions (mm)
Type
l
max
B1405
12.5
1
17
B404
12.5
1
17
B406
12.5
1
17
General technical data
Max. operating voltage for B404 and B406
(T
A
= 60
C)
V
max
550
VDC or VAC
Max. operating voltage for B1405
(T
A
= 60
C)
V
max
760
VDC or VAC
Rated voltage for B404 and B406
V
R
500
VDC or VAC
Rated voltage for B1405
V
R
690
VDC or VAC
Switching cycles
N
100
Reference temperature
(typ.)
T
ref
60
C
Operating temperature range
(V = 0)
T
op
40/+125
C
Operating temperature range
(V = V
max
)
T
op
0/+40
C
Electrical specifications and ordering codes
Type
I
R
mA
I
S
mA
I
Smax
(V = V
max
)
A
I
r
(V = V
max
)
typ.
mA
R
R
R
R
%
R
min
Ordering code
Rated voltage = 500 VDC or VAC
B404
4
9
0.4
1.0
3500
16
2880
B59404B0060A040
B406
2.5
6.5
0.3
1.0
5500
28
3800
B59406B0060A040
Rated voltage = 690 VDC or VAC
B1405
5
10
0.4
1.0
2400
25
2000
B59405B1060A040
Overcurrent protection
Rods, uncoated, 500 V / 690 V
B404, B406, B1405
Page 2 of 7
Please read Important notes and
Cautions and warnings at the end of this document.
Characteristics (typical)
PTC resistance R
PTC
versus
PTC temperature T
PTC
(measured at low signal voltage)
PTC current I
PTC
versus PTC voltage V
PTC
(measured at 25
C in still air)
Switching time t
S
versus switching current I
S
(measured at 25
C in still air)
Overcurrent protection
Rods, uncoated, 500 V / 690 V
B404, B406, B1405
Page 3 of 7
Please read Important notes and
Cautions and warnings at the end of this document.
Characteristics (typical)
PTC resistance R
PTC
versus
PTC temperature T
PTC
(measured at low signal voltage)
PTC current I
PTC
versus PTC voltage V
PTC
(measured at 25
C in still air)
Switching time t
S
versus switching current I
S
(measured at 25
C in still air)
Overcurrent protection
Rods, uncoated, 500 V / 690 V
B404, B406, B1405
Page 4 of 7
Please read Important notes and
Cautions and warnings at the end of this document.
Cautions and warnings
General
EPCOS thermistors are designed for specific applications and should not be used for purposes
not identified in our specifications, application notes and data books unless otherwise agreed
with EPCOS during the design-in-phase.
Ensure suitability of thermistor through reliability testing during the design-in phase. The
thermistors should be evaluated taking into consideration worst-case conditions.
Storage
Store thermistors only in original packaging. Do not open the package before storage.
Storage conditions in original packaging: storage temperature
25
C ... +45
C, relative
humidity
75% annual mean, maximum 95%, dew precipitation is inadmissible.
Avoid contamination of thermistors surface during storage, handling and processing.
Avoid storage of thermistor in harmful environment with effect on function on long-term
operation (examples given under operation precautions).
Use thermistor within 6 months after delivery.
Handling
PTCs must not be dropped. Chip-offs must not be caused during handling of PTCs.
Components must not be touched with bare hands. Gloves are recommended.
Avoid contamination of thermistor surface during handling.
Soldering
Use rosin-type flux or non-activated flux.
Insufficient preheating may cause ceramic cracks.
Rapid cooling by dipping in solvent is not recommended.
Complete removal of flux is recommended.
Mounting
Electrode must not be scratched before/during/after the mounting process.
Contacts and housing used for assembly with thermistor have to be clean before mounting.
Especially grease or oil must be removed.
When PTC thermistors are encapsulated with sealing material, the precautions given in chapter
"Mounting instructions", "Sealing and potting" must be observed.
When the thermistor is mounted, there must not be any foreign body between the electrode of
the thermistor and the clamping contact.
The minimum force of the clamping contacts pressing against the PTC must be 10 N.
During operation, the thermistor's surface temperature can be very high. Ensure that adjacent
components are placed at a sufficient distance from the thermistor to allow for proper cooling at
the thermistors.
Ensure that adjacent materials are designed for operation at temperatures comparable to the
surface temperature of thermistor. Be sure that surrounding parts and materials can withstand
this temperature.
Avoid contamination of thermistor surface during processing.
Overcurrent protection
Rods, uncoated, 500 V / 690 V
B404, B406, B1405
Page 5 of 7
Please read Important notes and
Cautions and warnings at the end of this document.
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