PTH7M/491 Ser ies
THERMISTOR PRODUCTS
PTC THERMISTOR
FOR MOTOR STARTER
560 CG01-J Rev.1
The PTH7M/491 Series is specifically designed for appliance
application in refrigerators, air conditioners and freezers and feature
an encapsulated construction and “quick connect” terminations to
facilitate installation and service. The exceptionally low resistance
of this Posistor®in the off condition allows a maximum current to
flow in the starting winding. As the temperature of the Posistor®
increases, so does its resistance. The starting winding is essentially
isolated from the running winding once the motor has reached
operating speed because of this increase in Posistor®resistance.
FEATURES
■No starting contacts to pit or wear
■May be directly substituted for start switches without
redesigning motor
■Encapsulated construction
■Acoustically and electrically noise free
■Vibration and shock resistant
■Long operating life
■Ideal for explosion proof motor applications
■Quick connect terminations
SPECIFICATIONS
DIMENSIONS: mm
STARTING SYSTEMS OF MOTORS APPLICATION CIRCUITS
PART NUMBERING SYSTEM
PTH7M 4R7 M B3 PTH491 A 01 AR 3R3 N 160
PTH7M RESISTANCE RESISTANCE STARTING PTH491 STARTING OTHER CURIE RESISTANCE RESISTANCE MAX.
SERIES VALUE TOLERANCE SYSTEM SERIES SYSTEM SPECIFICATION POINT VALUE TOLERANCE VOLTAGE
M: ±20% B3: CSR A: CSR AR: 120°C M: ±20% 160: 160V
C1: RSIR B: CSIR AS: 135°C N: ±30% 300: 300V
C2: RSIR C: RSIR
D2: RSCR
D3: RSCR
Type PTH491A01 PTH7M-B3 PTH7M-C1 PTH7M-D2
Starting PTH491B01 PTH7M-C2 PTH7M-D3
Capacitor Start
Induction Run
Capacitor Start and
Capacitor Run
Resistance Start
Induction Run
Permanent Split
Capacitor
CSIR Motor CSR Motor RSIR Motor RSCR Motor
PTH491A, B: Discrete type PTH7M, B, C, D: Plug-in type (2-receptacle type) PTH491: Optional product, not recommended for new design
Resistance Voltage Current Starting Resistance Voltage Current Starting
Part Number Value (Ohms) max. (V) max. (A) System Part Number Value (Ohms) max. (V) max. (A) System
at 25°C at 25°C
PTH7M Series Fail-Safe Backup Function PTH7M330MC2 RSIR
PTH7M4R7MB3 CSR PTH7M330MD2 33 ± 20% 355 6 RSCR
PTH7M4R7MC1 RSIR PTH7M330MD3
PTH7M4R7MC2 4.7 ± 20% 180 12 PTH491 Series
PTH7M4R7MD2 RSCR PTH491A01AR3R3N160 3.3 ± 30% 160 12
PTH7M4R7MD3 PTH491A01AR4R7N180 4.7 ± 30% 180
PTH7M6R8MB3 CSR PTH491A01AR6R8N200 6.8 ± 30% 200 10
PTH7M6R8MC1 RSIR PTH491A04AR6R8N225 225 13
PTH7M6R8MC2 6.8 ± 20% 200 10 PTH491A01AR100N225 10 ± 30% 9
PTH7M6R8MD2 RSCR PTH491A04AR100N315 315 12
PTH7M6R8MD3 PTH491A01AR150N250 15 ± 30% 250 8 —
PTH7M100MB3 CSR PTH491A04AR150N355 355 10
PTH7M100MC1 RSIR PTH491A01AR220N300 22 ± 30% 300 7
PTH7M100MC2 10 ± 20% 225 9 PTH491A04AR220N400 400 9
PTH7M100MD2 RSCR PTH491A01AR330N355 33 ± 30% 355 6
PTH7M100MD3 PTH491A04AR330N450 450 8
PTH7M330MB3 33 ± 20% 355 6 CSR PTH491A01AR470N400 47 ± 30% 400 5
PTH7M330MC1 RSIR PTH491A04AR470N500 500 7
*Tab terminal size: PTH7M–No. 250; PTH491A–No. 250; PTH491B–No. 187
PTH7M4R7MB3 PTH491A01AR3R3N160
1
19.5 524.5
5
19 22
415
4
1
23 16.5
6.5
4.5
8
9
191.5 1.5
8
11.66
4.7
2.5
2.5
15
31 11
20 28 39
4.5
8
33 40.5
