Digistart D3: User Guide
31
Issue: G
Inside delta installation, non-bypassed
6/T3
2/T1
5/L3
3/L2
1/L1
COM1
RLO1
4/T2
K1
K1
F1
U1(1) U2(4)
V1(2)
V2(5)
W1(3)
W2(6)
M
3
08346.
B
E
K1
Main contactor (strongly
recommended)
F1
Semiconductor fuses
(optional)
COM1,
RLO1
Relay output A (= Main
Contactor, default)
4.4 Fuse information
4.4.1 Power Supply Fuses
Semiconductor fuses can be used for Type 2 coordination (according to IEC 60947-4-2 standard) and to reduce the
risk of damage to SCRs from transient overload currents.
HRC fuses (such as Ferraz/Mersen AJT fuses) can be used for Type 1 coordination according to IEC 60947-4-2
standard.
NOTE
Fuses are not delivered with Digistart D3 soft starters.
CAUTION
Adaptive Control controls the motor's speed profile, within the programmed time limit. This may result in a
higher level of current than traditional control methods.
For applications using Adaptive Control to soft stop the motor with stop times greater than 30 seconds, motor branch
protection should be selected as follows:
•
standard HRC line fuses: minimum 150% motor full load current
•
motor rated line fuses: minimum rating 100/150% motor full load current
•
motor control circuit breaker minimum long time setting: 150% motor full load current
•
motor control circuit breaker minimum short time setting: 400% motor full load current for 30 seconds
NOTE
Fuse selection is based on a 400% FLC start for 20 seconds in conjunction with standard published starts
per hour, duty cycle, 40°C ambient temperature and up to 1000 m altitude. For installations operating
outside these conditions, consult your local supplier.
These fuse tables contain recommendations only. Always consult your local supplier to confirm the
selection for your particular application.
