Delta Ultron Series User Manual page 8

NOTE:
1
* Only applicable when the UPS has the corresponding built-in fuses, and the
configurations of the UPS's built-in fuses must meet the protective device's
requirement No.7 below.
300kVA
800A
4. Each protective device should have the functions of overcurrent protection, short circuit
protection, insulating protection and shunt trip feature. Please refer to the table below
for the UPS cut-off current (Icc).
300kVA
10kA
5. When selecting the protective devices, please take each power cable's current capacity
and the system's overload capacity (please refer to Appendix 1: Technical
Specifications) into consideration. Besides, the short-circuit capacity of the upstream
protective devices must be equal to or larger than the capacity of the UPS's input
protective devices.
6. When the UPS has abnormalities and the input short-circuit current reaches 20kA, the
UPS's internal semi-conductor fast-acting fuses need 8 ~ 10ms to be blown. Thus, the
upstream protective devices' reaction time should be more than 10ms so that the UPS's
semi-conductor fast-acting fuses would have sufficient time to block the system
breakdown and let the UPS transfer to Bypass mode.
7. If the UPS is supplied by a power source whose neutral is grounded, each protective
device must be a 3-pole type. If the UPS is supplied by a power source whose neutral is
not grounded, each protective device must be a 4-pole type.
8. The recommended electrical rating of the backfeed protective device is as follows.
300kVA
690V/ 630A
Ultron DPS Series
400kVA
1000A
400kVA
12.12kA
400kVA
690V/ 800A
8
500kVA
1250A
500kVA
15.16kA
500kVA
690V/ 1000A
600kVA
1500A
600kVA
18.18kA
600kVA
690V/ 1250A