Backup Loads Supported by Powershare System

Backup Load Selection Overview

Common Loads Include in Backup Circuit of Powershare System?
120 V Loads Lights / plugs / small appliances Include
240 V Loads Electric range / stove / oven Include
Air conditioner(s) Include if air conditioner LRA ≤ 110 A1
Tankless electric water heater (typically connected with multiple breakers Include if water heater kW ≤ Powershare continuous backup capability1
Water pump(s) or other large motor loads Include if motor ≤ 3 HP or motor breaker ≤ 30 A1
All other loads Include if breaker ≤ Powershare continuous backup capability1

1As noted in Largest Load in Backup Circuit below, the size of the Universal Wall Connector breaker determines the largest load that can be included in the backup circuit. For instance, if Universal Wall Connector is installed on a 30 A breaker, an air conditioner on a 40 A breaker cannot be included in the backup circuit, even if its LRA is < 110 A.

Load Calculation Considerations

A load calculation must be performed on the home to determine the size of the breaker that can be installed for Universal Wall Connector (see Universal Wall Connector Breaker Size for breaker size options). Consult local code to ensure load calculations are performed correctly based on the jurisdiction of the installation.

Consider the Universal Wall Connector breaker as a load during on-grid vehicle charging.

Largest Load in Backup Circuit

The largest load that can be supported in the backup circuit depends on the size of the breaker installed for the Wall Connector:
Wall Connector Breaker Size* Powershare Continuous Backup Capability** Power Output at 240V Required Current Limit Setting
60A (default) 48A 11.5kW N/A
50A 40A 9.6kW See Power Control Systems
40A 32A 7.6kW
30A 24A 5.7kW
20A Not recommended
15A Not recommended

System Load Start Capability

Some equipment, such as air conditioning units, require a higher influx of current to start the equipment's motor, compared to the continuous amps required once the motor is running. This quick burst of current utilization is called the inrush current, and is indicated by the Locked Rotor Amps (LRA) specified as required to start the device. Although the inrush current lasts for less than half a second, it could overload the Powershare system.

  • The Powershare system has a load start capability of 110 A LRA
  • The supported running load amps (RLA) is equal to the Powershare Continuous Backup Capability listed above; if the Wall Connector is installed on a 60 A breaker, the supported RLA is 48 A
  • For equipment that does not include LRA on the equipment label, Powershare systems can support motor loads up to 3 HP or 30 A
For any equipment that exceeds the supported LRA / RLA / maximum motor load sizing:
  • Relocate the equipment out of the backup circuit / upstream of the Powershare Gateway
  • Utilize a motor soft starter (temporarily reduces the electric current surge during start-up). Reference the equipment manufacturer documentation to learn if the motor is compatible with a soft starter

Example:

Consider a Powershare system installed with:
  • Universal Wall Connector on a 60 A breaker
  • Air conditioning unit with 200 A LRA
This system can only support up to 110 A LRA. To resolve the situation, the installer can:
  • Move the air conditioner breaker upstream of the Powershare Gateway
  • Install a motor soft starter if compatible with the air conditioner