Hello, and welcome to this video
about specific safety measures on the AC side,
for electrical installations with photovoltaic production.
In buildings where photovoltaic production is used for self-consumption,
the photovoltaic system is an integral part of the electrical installation.
In this video, I will explain
some of the main specific safety measures
required on the AC side for such installations:
loss-of-mains protection,
location of overcurrent protection,
and, isolation and switching of the photovoltaic supply system.
Loss-of-mains protection is required
by grid codes, and by energy distributors,
for installations with photovoltaic self-consumption.
This protection guarantees
that in case of utility supply outage,
the installation will not energize the distribution network,
which could compromise safety of utility workers.
Loss-of-mains protection can be implemented
by a dedicated protection device,
generally located at the photovoltaic system feeder.
Another option is to use grid-tie photovoltaic inverters
with integrated loss-of-mains protection,
if it is accepted by the energy distributor.
Check the solar inverter datasheet
to confirm it includes loss-of-mains protection,
and to verify appropriate standards compliance.
Another safety measure is AC overcurrent protection
for the photovoltaic power supply system.
To isolate electrical faults on the photovoltaic installation,
an overcurrent protection device must be located at the point
where the photovoltaic system is connected
to the building’s electrical installation.
It is essential to include the overcurrent protection in this exact location,
to avoid tripping the main circuit breaker
in case of fault in the photovoltaic feeder.
To ensure things work properly
this overcurrent protection
should be coordinated with the main circuit-breaker
to guarantee selectivity.
This selectivity may not be so easy to achieve
in particular when the photovoltaic production capacity
is equivalent to or higher than the building installed power.
In this case, the circuit breaker at the photovoltaic incomer
has the same rating or higher than the main circuit breaker,
as shown in this example.
Thus, to ensure selectivity between the two breakers, you may
oversize the main circuit breaker,
or split the photovoltaic system into smaller systems,
or consider time selectivity, for applications higher than 630 Amps.
Now, let’s consider the isolation and switching
of the photovoltaic power supply system. Now, let’s consider the isolation and switching
of the photovoltaic power supply system.
First, an AC disconnection device
must be located at the photovoltaic switchboard,
to isolate the photovoltaic system
from the rest of the electrical installation during maintenance.
Next, an isolation function must be provided for the photovoltaic inverters,
by disconnection means, on both the DC side and the AC side.
To sum up, certain specific safety measures are required
on the AC side of installations with photovoltaic production, including:
Loss-of-mains protection
Overcurrent protection for the photovoltaic power supply system,
which must be located on the building busbar side,
and AC isolation and switching for the photovoltaic system.
In our next videos, I will cover additional protection measures, such as:
surge protection
residual current devices selection,
or specific protection requirements for installations
operating both grid connected and off grid.
Thank you for watching!
Feel free to share, and see you soon!