UL 1741 PCS Requirements
UL 1741 PCS compliance may be required by the interconnecting utility or site host. If UL 1741 PCS compliance is required according to applicable site design, follow the guidance in this section.
The Tesla battery system is UL 1741 PCS-compliant with the following nominal voltages:
- 240V ( Split Phase)
Compliance with UL 1741 PCS can be achieved for system sizes under 200A with a Backup Switch according to the requirements below.
Busbar Labeling Requirements
The PCS-controlled current setting for each busbar shall be indicated with a field-applied marking label on the conductor or in close proximity to the busbars. Refer to the label below, filling the blank with the setting value:
CT Labeling Requirements
The following label must be posted near the installation of any Neurio CTs:
Required UL 1741 PCS Compliance Information
Note
The Tesla Powerwall+ system is
certified to UL 1741 PCS for the energy storage system (ESS) operating modes of
import and export only. The installer can select three modes of operation for the
system: No Site Export, PV Only Export, or PV, Battery Export.
- PV ONLY EXPORT: The battery will not export beyond the site meter, other than inadvertent export. The export at the site meter will be limited to the export from as measured by the solar meter.
- NO SITE EXPORT: The battery and solar will not export beyond the site meter, other than inadvertent export.
- PV, BATTERY EXPORT: The battery and solar will export beyond the site meter.
Note
To achieve UL 1741 PCS Import Only
behavior, either PV Only
Export or NO SITE
EXPORT must be selected. When the selected Grid Code applies to a region
that requires UL 1741 PCS, such as California UL 1741 SA, the default setting is PV Only Export. In the
locally hosted Device Setup (in Tesla One) it is possible to further restrict the system to NO SITE EXPORT; however once
set, it is not possible to change back to PV Only Export. It is not
possible to configure the system to allow BATTERY EXPORT.
Note
To achieve UL 1741 PCS Export Only
behavior, PV, BATTERY EXPORT
must be selected and the import rule must be set to charge only from solar (and not
charge from the grid). When the selected Grid Code applies to a region that requires
UL 1741 PCS, such as California UL 1741 SA, the default setting is PV ONLY EXPORT. In the
locally hosted Configuration Interface it is possible to further restrict the system
to NO SITE EXPORT; however
once set, it is not possible to change back to PV ONLY EXPORT or PV, BATTERY EXPORT.
Note
The maximum operating currents in controlled busbars or conductors are limited by
the settings of the power control system (PCS) and may be lower than the sum of the
currents of the connected controlled power sources. The settings of the PCS
controlled currents may be used for calculation of the design currents used in the
relevant sections of NEC Article 690 and 705.
Note
This system is equipped with a power control system (PCS) which is suitably rated
to provide branch circuit overcurrent protection. The controlled current setting
shall not exceed the rating of any controlled busbars or conductor ampacity.
Warning
Configuration of power control settings system or changes to
settings shall be made by qualified personnel only. Incorrect configuration or
setting of the power control settings may result in unsafe conditions.
Warning
Only qualified personnel shall be permitted to set or change the
setting of the maximum operating current of the PCS. The maximum PCS operating
current setting shall not exceed the busbar rating or conductor ampacity of any PCS
controlled busbar or conductor.
Note
Maximum Overcurrent protection
rating for PCS Controlled Conductor: 200 A.
Note
Maximum PCS Controlled Current setting: 200 A.
