J

J

minimum size

J

J

fast response charakteristic

J

J

single-, twin- and triplet- version

Benefits

J

J

Heavy-duty motors

J

J

electric drives

J

J

mechanical engineering

Applications

 PTC-Temperature-Sensors 
 PTC Thermistors, Motor-PTC 
 Single- and Triplet- Version 

  type

YAM

EF1

  Description    

  Technical data    

PTC-temperature sensors are used for thermal protection of electric 
machinery and control cabinets, especially electric motors. The 
structure ensures a fast response time and a simple installation.
The function is obtained by a strong nonlinear PTC effect of the 
resistor. The usable range is ± 5 K around the nominal temperature. 
The evaluation is carried out by means of an electronics which detects 
the sudden increase in resistance and initiates a corresponding action 
(throttling, shutdown, etc.).
The thermistors are designated according to their nominal switch-off 
temperature T

NAT

. Whereas the range below T

NAT

-20  is  not  defined. 

Standards for single / triplet PTC thermistors are DIN 40081/40082.

Description

Dimensions

Single thermistor: 

YAM1, EF1

Triplet thermistor: 

YAM3

Nominal response temperature

80 °C ... 180 °C ( add. 145 °C and 155 °C )

Maximum allowable operating temp.

200 °C

Maximum allowable operating voltage

25V (+25°C)

Maximum allowable power dissipation

690 mW ( +25 °C )

Resistance R

25

≤

 100 

Ω

≤

 300 

Ω

Resistance at  T

NAT

 -5 K

≤

 550 

Ω

≤

 1.650 

Ω

Resistance at T

NAT

 +5 K

≥

 1.330 

Ω

≥

 3.990 

Ω

Resistance at T

NAT

 +15 K

≥

 4.000 

Ω

≥

 12.000 

Ω

Tolerance of T

NAT

±5K

±5K

Dielectric strength

2,5 KV AC

Connection line

PTFE-insulated leads AWG26

Length of connecting leads

520 mm ± 10mm

520-180-180-520 mm ± 10mm

YAM:  

PTC-pill with shrink tube and epoxy resin

EF1:  

PTC-pill with screw housing with M4- or M6-thread

  Versions    

  Identification color (leads)    

type

illustration

drawing 

dimensions ( mm )

technical 

specification

YAM1

520 

±

10

8

+3

0

ty

p.

 3

max.

 3,

5

12

0

-2

180 

±

5

YAM3

YAM1

10

500 

u

10

8

4
M

YD1_EF1

520 

±

10

8

+3

0

12

0

-2

ty

p.

 3

max.

 3,

5

shrink tube and

epoxy resin

YAM3

520 

±

10

8

+3

0

ty

p.

 3

max.

 3,

5

12

0

-2

180 

±

5

YAM3

YAM1

10

500 

u

10

8

4
M

YD1_EF1

520 

±

10

8

+3

0

12

0

-2

ty

p.

 3

max.

 3,

5

shrink tube and

epoxy resin

EF1

520 

±

10

8

+3

0

ty

p.

 3

max.

 3,

5

12

0

-2

180 

±

5

YAM3

YAM1

10

500 

u

10

8

4
M

YD1_EF1

520 

±

10

8

+3

0

12

0

-2

ty

p.

 3

max.

 3,

5

srew housing with

M4- oder M6-thread

type

T

NAT

 °C

YAM1, EF1: single-PTC

standard ID-color

YAM3: triple-PTC
standard ID-color

YAM

EF1

80

white-white

white-yellow-yellow-white

90

green-green 

green-yellow-yellow-grün

100

red-red

red-yellow-yellow-red

110

brown-brown

brown-yellow-yellow-brown

120

gray-gray 

gray-yellow-yellow-gray

130

blue-blue

blue-yellow-yellow-blue

140

white-blue

white-yellow-yellow-blue

145

white-black 

white-yellow-yellow-black

150

black-black

black-yellow-yellow-black

155

blue-black

blue-yellow-yellow-black

160

blue-red

blue-yellow-yellow-red

170

white-green

white-yellow-yellow-green

180

red-white

red-yellow-yellow-white

YAM3 120 05 520 180 180 520

Type triplet

T

NAT

 (°C) and tolerance

Lead wire 1

Connecting lead wires

Lead wire 2

  Ordering example    

  Temperature-resistance curve    

Also versions in twins are possible.
Deviations from the standard generally on request.

NA

T

T 

     

-5

NA

T

T 

     

+5

NA

T

T 

     

+1

5

250Ω

550Ω

1330Ω

Ω

T

2

6
4

10k

2

6
4

1k

2

6
4

100k

4000Ω

100

2

10

°C

10

0

-10

-20

R

T 

     

-2

0

NA

T

Ω

T

2

6
4

10k

2

6
4

1k

2

6
4

100k

100

2

10

°C

20

0

-20

R

80 90 100 11

0

12

0

130

14

0

15

0

16

0

40 60 80 100 120 140 160

200

4

T       (°C)

NAT

Täschenwaldstr. 3 
75181 Pforzheim 
Deutschland 

Tel.: +49 7231 787-0 
Fax: +49 7231 787-155 

 
info@microtherm.de 
www.microtherm.de

Microtherm GmbH

05/2017-Technical subject to change without notice