
MANUAL MOTOR STARTER GUIDE
APRIL 19
19/80
2.2.7 Temperature rise of the manual motor starter
ABB tests the manual motor starters according to the Standard IEC 60947-1 table 2 and 3. This table indicates the
maximum temperature rise of the manual motor starters. Here you will find some example for the temperature rise:
Terminal material
Temperature-rise limits
a, c
in Kelvin [K]
Bare copper
60
Bare brass
65
Tin plated copper or brass
65
Silver plated or nickel-plated copper or brass
70
Other metals
b
a The use in service of connected conductors significantly smaller than those listed in Tables 9 and 10 could
result in higher terminals and internal part temperatures and such conductors should not be used without the
manufacturer’s consent since higher temperatures could lead to equipment failure.
b Temperature-rise limits to be based on service experience or life tests but not to exceed 65 K.
c Different values may be prescribed by product standards for different test conditions and for devices of
small dimensions, but not exceeding by more than 10 K the values of this table.
Table 4: Table 2 from IEC 60947-1 Temperature-rise limits of terminals
Accessible parts
Temperature-rise limits
a
in Kelvin [K]
Manual operating means:
Metallic
Non-metallic
15
20
Parts intended to be touched but not hand-held:
Metallic
Non-metallic
30
40
Parts which need not be touched during normal operation b:
Exteriors of enclosures adjacent to cable entries:
Metallic
Non-metallic
Exterior of enclosures for resistors
Air issuing from ventilation openings of enclosures for resistors
40
50
200b
200b
A Different values may be prescribed by product standards for different test conditions and for devices of small dimensions but
not exceeding by more than 10 K the values of this table.
b The equipment shall be protected against contact with combustible materials or accidental contact with
personnel. The limit of 200 K may be exceeded if so stated by the manufacturer. Guarding and location to prevent danger is the re-
sponsibility of the installer. The manufacturer shall provide appropriate information, in accordance with 5.3.
Table 5: Table 3 from IEC 60947-1 Temperature-rise limits of accessible parts.