On-Grid&Back-Up Connection - LG LGES-5048 User Manual

Battery Protection
Battery will provide charge/discharge current limitation under the following conditions
• Battery SOC is lower than I-DOD (Depth of discharge).
• Battery voltage is lower than discharge voltage.
• Battery over temperature protection
• Battery communication is abnormal for lithium battery.
• BMS charge/discharge limitation for lithium.
When charge/discharge current limitation protection happens:
• Under on-grid mode, battery charge/discharge operation could be abnormal.
• Under off-grid mode, Back-Up supply will shut down.
Note:
• The inverter and battery cannot be used in off-grid designs
• Under on-grid mode, battery is protected from over discharge by DOD and discharge voltage.
• The DOD setting of a battery prevents the inverter from discharging battery reserve power. As
soon as the DOD is reached the load of building will only be supported by either PV power or the
grid. If there are continuous days when little or no battery charging occurs, the battery may
continue to self-consume energy to support communications with the inverter.
2.4.4 On-Grid & Back-up Connection
An external AC breaker is needed for on-grid connection to isolate the inverter from the utility grid
when necessary.
The requirements for the on-grid AC breaker are shown below.
Inverter Model
LGES-5048
LGES-5048-NS
Note: The absence of AC breaker will lead to inverter damage if an electrical short circuit happens on
grid side.
1. Use separate AC breakers for individual
inverters.
AC breaker
AC breaker
Requirement of AC cable connected to On-Grid and Back-Up side.
Make sure the inverter is totally isolated from any DC or AC power before connecting the AC
cable.
Note:
1. Neutral cable shall be blue, line cable shall be black or brown (preferred) and protective earth cable
shall be yellow-green.
2. For AC cables, PE cable shall be longer than N&L cables, so in case that the AC cable slips or is taken
out, the protecting earth conductor will be the last to take the strain.
AC Breaker Specification
40A / 230V (e.g. DZ47-60 C40)
40A / 230V (e.g. DZ47-60 C40)
AC breaker
Grid
12
2. On the AC side, an individual breaker
should be connected between the inverter
and grid but before any loads.
AC breaker
:
Grid
Load