
6LE007317A
12
1P + N
2P + N
2P
3P
L1
L2
L1
L2
L3
L1
L2
L1
L2
L3
N
L1
N
N
3P + N
7.3.1. Power Supply
The HZI855 controller is Self-powered from the voltage sensing of any available source, and may also be powered (as a
backup from saved source) from the DC auxiliary power input (24 VDC).
7.3.1.1. Dual Power Supply / Sensing
The HZI855 controller will be automatically supplied from the voltage sensing connectors of both sources thanks to an
internal DPS (dual power supply) module that in case main source failure, will immediately switch to the secondary source
supply the device.
NOTE: The nominal auxiliary power supply feeding the sensing terminals must be within the limits of 88
➡
576 VAC.
7.3.1.2. DC Power Supply
HZI855 controller includes an optional DC power supply input to power the controller in case both sources are off. The DC
power supply voltage needed to power up the controller is between 9 VDC and 28 VDC.
For single phase networks,
the neutral has to be bridged
from N to L2.
NOTE: The HZI855 must include a SCPD such
as fuses on each phase of the voltage sensing
control wiring.
1A gG fuses are recommended.
DC supply is optional for the utilization of the
controller.
- The 24 VDC is SELV (safety extra low voltage)
and must be fused and grounded in the
installation.*
- RS485 includes functional insulation.