
Protection For Coils / Windings
Thermal Cut-outs/Bimetal Thermostats
This thermostat operates as a thermal cutout. A thermally sensitive bimetal snap-element with double contacts either opens or closes an electrical circuit by switching at a pre-set response temperature. Reset follows automatically after a considerable drop in temperature.
B12 / B13 (Double Contacts)
Applications
Single Phase Motors, Generators, Convertors, Transformers, Pumps, Heating Elements, Signal Transmitters, Fire Detectors, Magnets, Relays, Chokes, Coils, Power Supplies, Inverters
Technical Data
ratings | B12A / E | B12B / G | B13N / T | |||
version | normally closed Cantherm Code=2 | nnormally open Cantherm Code=1 | normally closed / open | |||
rated current at 250 V 50/60 Hz (cos 0.95/0.6) | 6.3 A / 6.0 A | 10.0 A / 6.0 A | 13.0 A / 6.0 A | 5.0 A / 1.6 A | 1…100 mA (24 Vdc) | |
switching cycles under rated current | 10,000 | 5,000 | 1,000 | 5,000 | 10,000 | |
max. current under failure condition at 250 V 50/60 Hz (power factor 0.95) | 30.0 A | – | ||||
switching cycles under max. current | 100 | – | ||||
temperature rating Ta (steps in 5 K) | 70°C…160°C | 70°C…155°C | 70°C…160/155°C | |||
tolerances | standard:+/- 5 K | |||||
feature of automatic action | 1.B.M, 2.B, 1.C | 1.B | – | |||
contact resistance ( incl. wire of 100 mm ) | < 50 mΩ | |||||
hysteresis | 30 K ± 15 K1 | |||||
dielectric strength ( standard insulation ) | 2 kV | |||||
shock- / vibration testing( similar to EN 50155 ) | 400 m/s2sine half wave / 100 m/s2 5 Hz … 2,000 Hz sine | |||||
resistances to impregnation | tight against ordinary resins and lacquers | |||||
degrees of protection provided by enclosures ( EN 60529 ) | IP00 | |||||
suitable for use in protection category | I, II | – | ||||
approvals | VDE / ENEC | EN 60730-1 / -2-3 2) /-2-9 | ||||
UL | UL 2111 / UL 873 3) | |||||
CSA / cUL | C22.2 No. 77 / C22.2 No. 24 3) | |||||
CQC | GB14536.1-1998 / GB14536.10-1996 3) | |||||
1) at the Ta (upper and lower) limits the hysteresis could deviate 2) different power rating 3) details on request |
Standard wire ( length 100 ± 10 mm, stripped 6 ± 1 mm )
lead | Cantherm code |
temp. max. | operating voltage max. |
diameter insulation | cross section diameter2) | UL style |
black | ACDA | 150° C | 300 V | 1.57 mm | AWG24 / 0.24 mm2) | 3266 or 3398 |
yellow | AEDC | 1.80 mm | AWG20 / 0.48 mm2) | |||
black | AFDA | 2.15 mm | AWG18 / 0.96 mm2) | |||
white | LCDB | 200° C | 600 V | 0.90 mm | AWG24 / 0.24 mm2) | 3557 |
white | LEDB | 1.26 mm | AWG20 / 0.61 mm2) | |||
white | LFDB | 1.50 mm | AWG18 / 0.96 mm2) | |||
black | ASDA 3) | 150° C | 300 V | 1.65 mm | AWG20 / 0.81 mm | 3266 or 3398 |
white | DEDB | 200° C | 300 V | 1.51 mm | AWG20 / 0.81 mm | 1180 |
2)AWG20 is recommended 3)Solid Wire NOTE: Additional wires available upon request. |
Standard insulation
control type | nc | no | Cantherm code | illust. | drawing dimensions (mm) | technicals specification | approvals1) |
B12 | A | B | Class B U103 | C
Class F U107 | G |
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shrink cap potted |
VDE,UL, cUL |
B13 | N | T | |||||
B12 | A | B | U155 | X
U186 | 3 |
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cap of PPS potted |
VDE, UL, cUL |
B13 | N | T |
Specific variations U= insulation G= Housing
control type | nc | no | Cantherm code | illust. | drawing dimensions (mm) | technicals specification | approvals1) |
B12 | A | B | none | 0 | ![]() |
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not insulated potted |
VDE,UL,cUL, CSA |
B13 | N | T | |||||
B12 | A | B | U112 | L | ![]() |
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epoxy coated | VDE,UL, cUL |
B13 | N | T | |||||
B12 | A | B | U294 | G | ![]() |
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housing of PPS
potted |
VDE,UL, cUL |
B13 | N | T | |||||
B12 | A | B | Wire A800 | IZA | ![]() |
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not insulated
potted |
VDE,UL, cUL |
B13 | N | T | |||||
B12 | E | G | G702 | C | ![]() |
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aluminum housing
thread M4x6 potted Ta max. 150†C |
VDE,UL, cUL |
B13 | N | T | |||||
B12 | E | G | G714 | F | ![]() |
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brass housing
thread M4x5 potted Ta max. 150†C |
VDE,UL, cUL |
B13 | N | T |
Heating by current

The diagram is measured with a thermal control without any insulation in an oil bath.
Attention:
The heating depends on the thermal conduction of the control to the equipment or part which should be protected.
Ordering & Marking Example
Cantherm Ordering Example [ B12A12005AEDCC0E ] standard version | |||||||||
B12 | A | 120 | 05 | AE | FD | C | C | O | E |
type | normally closed | temperature | tolerance +/-5°C | wire leads UL3398 20 AWG | length D=4″ | color yellow | insulation U103 | housing – none | strip .25″ |
Marking |
B12A type (B12 nc)
12005 response temperature (120°C), tolerance (± 5K) 112C date of manufacture (Nov. 2012), country (C = Canada) |