IEC 60947-4-2-2020 pdf free download

IEC 60947-4-2-2020 pdf free download.Low-voltage switchgear and controlgear Part 4-2 : Contactors and motor-starters – Semiconductor motor controllers starters and soft-starters
Appareillage a basse tension Partie 4-2 : Contacteurs et demarreurs de moteurs-Gradateurs , demarreurs et
demarreurs progressifs a semiconducteurs de moteurs.
The relays shall comply with the requirements of Table 4 when tested as follows
a ) with the overload relay or starter in its enclosure , if normally fitted , and atA times the
current setting , tripping operation shall not occur in less than 2 h starting from the cold
state , at the value of reference ambient air temperature stated in Table 4 . However , when
the overload relay terminals have reached thermal equilibrium at the test current in less
than 2 h , the test duration can be the time needed to reach such thermal equilibrium :
b ) when the current is subsequently raised to B times the current setting , tripping operation
shall occur in less than 2 h :
c ) for class 2 , 3 , 5 and 10 A overload relays energized at C times the current setting , tripping
operation shall occur in less than 2 min starting from thermal equilibrium , at the current
setting , in accordance with 9.3.3 of EC 60034-1 : 2017
NOTE 2 Subclause 9.3.3 of EC 60034-1 : 2017 states : ” Polyphase motors having rated outputs not exceeding
315 kW and rated voltages not exceeding 1 kV shall be capable of withstanding a current equal to 1 . 5 times
he rated current for not less than 2 min
d ) for class 10 , 20 , 30 and 40 overload relays energized at C times the current setting .
tripping operation shall occur in less than 4 min , 8 min , 12 min or 16 min respectively .
starting from thermal equilibrium , at the current setting
e ) for semiconductor starter without current-limit function at D times the current setting
tripping operation shall occur within the limits given in Table 3 for the appropriate trip
class and tolerance band , starting from the cold state . For semiconductor starter with
current-limit function , the test shall be done at the maximum Jim and the tripping operation
shall occur within the time limits declared by the manufacturer according to 5.7.5
NOTE 3 For semiconductor starters with current-limit function and an overload relay having a current setting
range , the test with the maximum / m is related only to the maximum setting of the overload relay . The test at the
minimum setting can be done in the same way as without current-limit function
In the case of overload relays having a current setting range , the limits of operation shall
apply when the relay is carrying the current associated with the maximum setting and also
when the relay is carrying the current associated with the minimum setting.IEC 60947-4-2-2020 pdf free download.