ABB PRO-33.0-TL Series - Short-Circuit and Thermal Overload Protection; Inverter and AC Output Short-Circuit Protection; DC Input Reverse Current Protection and Monitoring; String Over-Current Protection and Monitoring (-SX Model)

36 Installation requirements
Short-circuit and thermal overload protection
 Inverter and AC output short-circuit protection
The inverter has an automatic AC over-current trip function which limits inverter
damage if there is, for example, an AC side short-circuit. Install an external circuit
breaker at the AC distribution board to protect the AC cable according to the local
regulations, the appropriate AC line voltage and the rated current of the inverter.
 DC input reverse current protection and monitoring
The inverter has a reverse polarity protection diode between the positive and
negative DC inputs to protect the inverter from reverse DC input connections. The
inverter generates a fault if reverse current flows between the positive and negative
DC inputs.
 String over-current protection and monitoring (-SX model)
The -SX model has pre-assembled string fuses on both positive and negative DC
inputs. Correctly-sized string fuses reduce the risk of fire and damage to the PV array,
DC cables and components, if short circuits or reverse connection of PV modules or
strings occur.
 Inverter and AC output cable thermal protection
The inverter protects itself against thermal overload. A circuit breaker must be
installed on the AC distribution board side to protect AC cabling and electrical grid
interface devices.
 External RCD
The inverter has an integrated DC and AC sensitive RCMU which can detect residual
(fault and leakage) currents. If the residual current is over 300 mA
rms
or a rapid rise of
over 30 mA
rms
is detected, the inverter disconnects from the grid.
The inverter can generate leakage currents of up to 300 mA. The total operational
leakage current depends on the operating conditions and on the type of PV module.
Exact values for leakage currents cannot be given.
If an external RCD is required by local regulations, use an RCD which has a nominal
rating of 300 mA per connected inverter.
Grid configurations
The permitted earthing configurations are TN-S, TN-C, TN-C-S and TT. IT earthing is
not permitted.