How to Build a Partial Home Backup System with AC300+B300
User Manual
Introduction
Thank you for choosing BLUETTI. This manual guides you through building a partial home backup system using the AC300 and B300 power units. BLUETTI is committed to sustainable, green energy storage solutions for indoor and outdoor use, trusted by millions globally across over 70 countries.
The AC300+B300 system is designed to provide reliable backup power for your home.
System Overview
This document covers two primary configurations:
- 120 Volts AC300+B300 Backup System
- 240 Volts AC300+B300 Backup System (Split Phase)
It also details necessary accessories, installation procedures, and setup instructions.
1. 120 Volts AC300+B300 Backup System
This configuration uses a single AC300+B300 set operating in "Single Phase" mode. Ensure the machine type setting is not changed if using a single set.
Required Accessories:
| Accessory | Quantity |
|---|---|
| Transfer switch: Reliance 310A Pro/Tran 2 | 1 |
| NEMA TT30-P to L14-30R extension cord | 1 |
| 30A AC charging cable | 1 |
? NOTE: Please refer to the Reliance 310A Pro/Tran2 manual before installation. You can find it at: Reliance Controls Manual Link
Installation Diagram (120V System):
The diagram illustrates the connection of the AC300+B300 backup system. It shows a "Main Panel" connected to a "Transfer switch Pro/Tran 2". The transfer switch manages power to a "Normal Load" and an "Essential Load". The AC300+B300 unit is connected to the transfer switch via a "30A AC Charging Cable" and a "TT30-P to NEMA L14-30 extension cord". A "L14-30 Socket" serves as the input to the transfer switch. Key components are labeled: 1: L14-30 Socket, 2: NEMA L14-30 Inlet on the transfer switch, 3: 30A AC Charging Cable, 4: TT30-P to NEMA L14-30 extension cord.
2. 240 Volts AC300+B300 Backup System (Split Phase)
To build a 240V Split Phase System, you need to pair two sets of AC300+B300 together. This configuration doubles the available output power and capacity.
Required Accessories:
| Accessory | Quantity |
|---|---|
| Transfer switch: Reliance 310A Pro/Tran 2 | 1 |
| AC300 split-phase output cable | 1 |
| NEMA L14-30R socket | 1 |
| AC300 30A split phase AC charging cable | 1 |
| Communication cable for split-phase function | 1 |
? NOTE: Please read the Reliance 310A Pro/Tran 2 manual before installation. You can find it at: Reliance Controls Manual Link
Before installing the Reliance Controls transfer switch system, create an emergency energy plan identifying essential appliances. It is highly recommended to "balance the load" between the two phases of the transfer switch, avoiding connecting high-wattage appliances solely to one AC300+B300 set.
Installation Diagram (Split Phase System):
The diagram illustrates the split-phase backup system setup. It shows a "Main Panel" connected to a "Transfer switch Pro/Tran 2", which powers a "Normal Load" and an "Essential Load". Two AC300+B300 units are connected to the transfer switch via a "30A Split-phase AC Charging Cable" and an "AC300 Split-phase Output Cable". A "NEMA L14-30 Socket" and a "NEMA L14-30 Inlet" are part of the connection pathway.
⚠️ Caution! The backup split phase system must be properly installed by a licensed electrician.
Configuration Steps:
- Turn off both AC300+B300 sets.
- Connect AC300+B300 sets to the transfer switch via the AC300 split-phase output cable. One TT-30 plug goes to each set.
- Connect the two AC300 units using the communication cable.
- Turn on either AC300+B300 set.
- Go to "Settings" and tap “Next”.
- Tap "Single Phase", the machine type option pops up, and select "Split Phase".
- Select the “Master” in the Machine Address pop-up window.
- Turn on the other AC300+B300 set. Repeat steps 5 and 6 to set its machine type to "Split phase".
- Select the “Slave” in the Machine Address pop-up window.
If the connection fails, clear the alarm history and reconnect.
Wiring Diagram (240V Split Phase):
The wiring diagram shows the 240V split-phase system. "240V Utility Power" connects to the "Main Panel". The main panel is wired to a "Transfer switch" which then supplies power to a "Normal load" and an "Essential load". The diagram includes a "NEMA L14-30 socket" and a "NEMA L14-30 inlet on the transfer switch". Color-coded lines represent the electrical connections. Notes emphasize that the backup system must be installed by a licensed electrician, voltage at outlets should be checked before plugging in appliances, and for actual wiring details, refer to Reliance PRO/TRAN2 installation instructions. It also notes that in the main panel, two Neutral/Ground bus bars are connected together with copper strips.
Connecting the AC300+B300 Sets to the Main Panel:
Charge the 240V split phase system using the AC300 30A split phase AC charging cable. Plug one end into a NEMA L14-30 socket (240V) and the other two connectors into the AC300s' AC input ports. The AC input ports should be connected to L1/N/PE and L2/N/PE, respectively. The current capacity of the AC input plug must be ≥ 30A.
The diagram shows the "30A split phase AC charging cable" connecting a NEMA L14-30 socket (labeled X(L1), W(N), Y(L2), G(PE)) to the AC input ports of two AC300 units, labeled "L1 N PE" and "L2 N PE".
❌ WRONG CONNECTION: DO NOT charge AC300+B300 with a standard AC charging cable in the split phase system, as this may cause damage to the batteries inside B300s and invalidate your warranty.
The diagram illustrates the L and N wire connections to the AC300 units, emphasizing "L: Live wire N: Neutral wire". It shows the AC300 units with their AC input ports, connected via a cable indicating L1, PE, and N.
? NOTE: The split phase system supports charging via solar panels. You can charge it by PV and the AC300 30A split-phase AC charging cable simultaneously. (AC input only through the AC300 30A split-phase AC charging cable, not the standard AC charging cable).
The diagram shows the overall 240V split phase system, including "240V Utility Power", "Main Panel", "Transfer switch", "sub panel", "Normal load", "Essential load", "NEMA L14-30 socket", and "NEMA L14-30 inlet on the transfer switch".
3. Accessories
3.1 Transfer Switch
Recommendation: Reliance Controls 310A PRO/TRAN 2 transfer switch.
An image shows the Reliance Controls 310A PRO/TRAN 2 transfer switch unit.
3.2 BLUETTI 30A AC Charging Cable
Please purchase this from the BLUETTI official store.
An image shows the AC300 30A AC Charging Cable.
3.3 BLUETTI AC300 Split-Phase Output Cable
Please purchase this from the BLUETTI official store.
Link: https://www.bluettipower.com
The cable features two NEMA TT-30 connectors on one end and a NEMA L14-30R connector on the other.
3.4 BLUETTI AC300 30A Split-Phase AC Charging Cable
Please purchase this from the BLUETTI official store.
Link: https://www.bluettipower.com/products/30a-ac-charging-cable-for-split-phase-function
An image shows the BLUETTI AC300 30A split-phase AC charging cable.
3.5 Communication Cable for Split-Phase Function
Please purchase this from the BLUETTI official store.
Link: https://www.bluettipower.com/products/communication-cable-for-split-phase-function
An image shows the communication cable with two blue connectors.
3.6 NEMA L14-30R Socket
Used for charging the 240V AC300+B300 split phase system.
Recommendation: Journeyman-Pro HJP 2710 NEMA L14-30R socket.
3.7 NEMA TT30-P to L14-30R Extension Cord
Used for connecting AC300+B300 to the sub panel.
Recommendation: Parkworld NEMA TT30-P to L14-30R extension Cord.
3.8 Circuit Breaker & Protection Box
If you have a residential solar array with a voltage of 12V-150V, it is strongly recommended to use a DC circuit breaker panel to enable or disable solar charging.
? NOTE: If there are two solar panel arrays with a total open circuit voltage of 12-150V, you also need two 2P 16A DC circuit breakers.
4. How to Install Reliance Controls
Please refer to the Reliance Controls website for detailed installation guides: www.reliancecontrols.com
Installation Videos:
- 4.1 How to install Reliance Controls ProTran2 - Part1, Tools and Planning: YouTube Link
- 4.2 How to install Reliance Controls ProTran2 - Part2, Mounting: YouTube Link
- 4.3 How to install Reliance Controls ProTran2 - Part3, Wiring: YouTube Link
- 4.4 How to install Reliance Controls ProTran2 - Part4, Replacing Circuit Breakers: YouTube Link
- 4.5 How to install Reliance Controls ProTran2 - Part5, Installing The Power Inlet Box: YouTube Link
- 4.6 How to install dd Controls ProTran2 - Part6, How To Operate: YouTube Link
5. More Information
Website: www.bluettipower.com
Email: service@bluettipower.com
