Delta Modulon DPH Series User Manual page 9

The installation of protective devices is highly recommended when the UPS is connect-
ed to power sources and critical loads.
The protective devices connecting to the UPS must be installed near the UPS and eas-
ily accessible for operation.
Protective Devices:
1. For single input, please install the protective devices (1) between the main AC
source and the UPS and (2) between the connected critical loads and the UPS.
2. For dual input, please install the protective devices (1) between the main AC source
and the UPS, (2) between the bypass source and the UPS and (3) between the
connected critical loads and the UPS.
3. Each protective device could be a breaker or a fuse. For the protective device's
rating current, please refer to the table below.
15kVA
60A
4. For selection of 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 device's must be equal to or higher than the capacity of the
UPS's protective devices.
If the UPS is supplied by a power source whose neutral is grounded, the backfeed
protective device installed as UPS input protection must be a 3-pole type. If the UPS is
supplied by a power source whose neutral is not grounded, the backfeed protective de-
vice installed as UPS input protection must be a 4-pole type.
The recommended electrical rating of the backfeed protective device is as follows.
15kVA
240V/ 60A
30kVA
125A
30kVA
240V/ 125A
1-3
1 Important Safety Instructions
45kVA
175A
45kVA
240V/ 175A
60kVA
225A
60kVA
240V/ 225A