Applicability

This article describes how to convert the Tigo energy storage system (ESS) from a whole-home backup configuration to a partial-home backup configuration. The applicable inverters, EI links are :

Inverter: TSI-3K1D, TSI-5K1D, TSI-6K1D, TSI-6K3D, TSI-10K3D, TSI-15K3D

EI-Link: TSS-1PS, TSS-3PS.

Required Accessories

Items	Single-phase Part#: 306-110100-0001	Three-phase Part#: 306-110100-0001
CTs with RJ45 connector (Order from Tigo)
RJ45 coupler (Installer to provide)
Extension CAT5 cable (Installer to provide)

Whole-Home and Partial-Home Backup

A typical Tigo EI Residential Solar Solution is designed to provide whole-home backup. In this configuration, the EI system is installed between the utility grid and the home’s service entrance panel. Current transformers (CT for single-phase systems) or an energy meter (for three-phase systems) are integrated into the EI-Link, simplifying on-site installation. In the event of a grid outage, the entire home—connected through the EI-Link—is powered by the battery system.

For partial-home backup configurations, an essential-load panel is added to the home’s electrical system. This panel contains breakers for selected critical circuits that the EI system will support during a grid failure. In this setup, the EI system is installed between the service entrance panel and the essential-load panel. A CT is placed at the main service panel and connected to the EI Inverter. During a grid outage, the system automatically isolates the essential-load panel and powers it with the battery, while preventing any back feed to the service entrance panel or the utility grid.

Partial Home Backup Installation Procedure

Fig. 2 Components layout for partial-home backup

Install the CT(s):

• Purchase CT from Tigo or a distributor.
• Clamp the CT to the live wires right after the main breaker in the service entrance panel. Ensure phase of wire match R, S and T respectively for 3phase.
• Ensure the arrow on the CT points towards the grid.
  

Connect the CT(s) to the inverter:

1. Remove the CAT5/6 cable from the Meter/CT port on the bottom of the EI Inverter. This cable is no longer required and can be disposed of.
2. Extend the CAT5 cable with a coupler. Please note the coupler is not waterproof.
3. Install the waterproof RJ45 connector to the CAT5/6 cable at the inverter end.
4. Crimp the ethernet cable with correct order. For example, T-568B below.
   
5. Test continuity with ethernet cable tester if there is one.   
6. Connect the CT CAT5/6 cable to the Meter/CT port underneath inverter and install the waterproof connector.

Configure the setup in the EI app:

1. In the EI app, open the system and tap the Settings icon.
   
2. Tap Edit System > Select Equipment > Inverters/VIEW DETAILS > CONNECT > Inverter Settings > Advanced Options > Backup Type
   
3. Tap Partial and SAVE.