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 Gateway 2 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:

Figure 1. PCS Field Marking Label

CT Labeling Requirements

The following label must be posted near the installation of any Neurio CTs:

Figure 2. CT Field Marking Label

Required UL 1741 PCS Compliance Information

Informational PurposesAn informational icon, calling your attention
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.
  1. 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.
  2. NO SITE EXPORT: The battery and solar will not export beyond the site meter, other than inadvertent export.
  3. PV, BATTERY EXPORT: The battery and solar will export beyond the site meter.
Informational PurposesAn informational icon, calling your attention
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.
Informational PurposesAn informational icon, calling your attention
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.
Informational PurposesAn informational icon, calling your attention
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.
Informational PurposesAn informational icon, calling your attention
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 IconA warning icon, calling your attention to a possibly risky situation
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 IconA warning icon, calling your attention to a possibly risky situation
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.
Informational PurposesAn informational icon, calling your attention
Note
Maximum Overcurrent protection rating for PCS Controlled Conductor: 200 A.
Informational PurposesAn informational icon, calling your attention
Note
Maximum PCS Controlled Current setting: 200 A.
Figure 3. Controlled Conductors in a Powerwall+ with Backup Gateway 2 System for Whole Home Backup
Figure 4. Controlled Conductors in a Powerwall+ with Backup Gateway 2 System for Partial Home Backup