The following preparation is required before the installation of FHP products:
1. Site survey (local utility, potential solar capacity, locations, cell signal)
2. Plan design (load calculations, battery sizing, NEC and building code compliance)
3. Preparation of materials and tools (may have to create CAN Cables)
4. Planning and preparation of installation sites
5. Networking Plan
We invite you to give us a call anytime, even before an installation to verify any design or install questions that may arise. Not sure what accessories to use? Need help with an integration? We are happy to help!
How do I decide the size of the breakers?
FranklinWH does not advise on breaker sizing as that should be done according to the NEC associated requirements but we do have a list of officially supported breakers for the aGate here: page 51:
Franklin-Home-Power-Installation-Guide-EN (franklinwh.com
Please note: if you decide to install aPower and aGate in the garage or near any parking place, reference appropriate building code requirements for placement or protection.
How are home loads calculated
1. List the names and quantity of loads by device family.
2. Gather the rated power of each load and sum for a total.
3. Based on the electricity bill, evaluate average daily power consumption.
The type and characteristics of backup loads decide the power capacity of the FHP system and whether the loads can work normally. FHP capacity configuration requires the starting current of home loads ＜ LRA capability of FHP system.
Typical home loads fall into two categories:
Surge load (large starting current), starting current is about 3 to 7 times the rated current when running.
Pure resistive load (small starting current), starting current ≤ 1 time the rated current.
For example, take an FHP system with rated power of 5kW is installed. When the grid power supply fails, there is no sunlight, the generator is not running, and the FHP is in backup mode. When a 3-ton air conditioner turns on, the inrush current from the FHP system will go up to 84A (4 times larger than the rated working current of FHP system). Since fixed-frequency air conditioners can have a long starting period, it may very well trigger the overcurrent protection of the FHP system, which would cause the home loads to lose power.
The nominal apparent power of the FHP system is determined by the total apparent power of backup loads.
FHP capacity requirement: Total apparent power of backup loads ＜ FHP apparent power
Where apparent power = nominal power (active power) / Power factor
If the sum of apparent power of all backup loads is larger than the nominal apparent power of FHP system, overload protection may be triggered, resulting in the power-off of some home loads when the FHP is working in off-grid mode with no sunlight and no generator working. The total active power of backup loads decides the maximum sustainability of the FHP system in backup mode. The longest backup time required by the customer can be obtained by analyzing the total active power of the home backup loads.
For example, if the total active power of all backup loads is 3kW, then the maximum sustainable backup time for the household is 13.6kWh/3kW≈4.5h when the only FHP source is a single aPower fully charged (SOC=100%). The smaller the total active power, the longer the backup time.
FHP System Configuration Recommendations
FHP system rated power ˃ the total rated power of home backup loads.
FHP system rated power ˃ 80% of the total rated power of the solar inverters.
FHP system inrush current ≥ the maximum inrush current for a single unit in home backup loads.
FHP system capacity ˃ the average backup power * backup time.
The backup plan for home loads are as follows:
Backup load port: Loads that are expected to stay energized in a grid power outage. When the grid power supply fails, the FHP takes over to power these loads.
Non-backup load port: Loads that do not need backup power from the FHP system. These loads can only be powered by the grid power supply.
Smart Circuit Module location: Loads that may be remotely controlled by the customer through the FranklinWH mobile app.
Additional Design Resources:
PowerPoint Presentation (franklinwh.com)--Example Plans
Split-CT-Installation-Guide (franklinwh.com)-Curious about split CT placement?