Page 65 - MCCB-XT2-XT4

ABB | SACE Tmax XT

9 - Motor protections

List The Motor Protection package, available by default and only for Ekip M Touch, comprises protections:
Name Type of protection Page
R JAM Motor block (post startup) 64
R STALL Motor block (always activated) 64
UC Under-current 65
U Phase loss 65
PTC Maximum temperature 66

The Motor protections conform to standard IEC 60947-4-1 and relative annex 2.

Trip class and parameters The trip class mentioned in standard IEC 60947-4-1 is available in Trip units with Motor Class parameter
(page 115).
Its value establishes:
• the trip time of L protection (Time t1)
• the start-up time (Motor start-up), calculated from the moment that at least one phase exceeds
the fixed threshold of 0.25 x I1, during which some protections are inhibited
• the thermal memory L reset time after a TRIP (tmem res)
Motor Class t1 (s) Motor start-up (s) tmem res (min)
5E 12 3 5
10E 22 5 10
20E 45 10 20
30E 72 20 33

Figure 23

NOTE: temporary switch-off during Motor Startup-up is valid and activated for protections
G, R Jam and U if enabled; if the protections are disabled they remain off before and after
Motor Start-up.

Thresholds Unlike the other current protections, the R Stall, R Jam and UC thresholds are not related to In, but to
threshold I1 (L protection), given as Ir in the respective configuration menus;
Example
Rating plug = 400 A, Threshold I1 = 0.8 In (--> 320 A); Threshold Ij = 2.5 Ir (--> 2.5 x 320 A = 800 A)

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