My solo PV installs so far have been with Enphase microinverters (micros). I haven't solo installed an Enphase battery yet.
Last March, I went to Enphase's free six-hour hands-on battery training in Sacramento. I'm glad I did. The trainer was Jarett Skeffington. He's a friendly and direct guy, who's been with Enphase for fourteen years.
My notes from the training are below, in the order that I took them.
Big thanks to Jarett and Enphase's Nathan Charles for reviewing these notes and sharing feedback (that I've incorporated) (any errors or omissions are 100% mine).
This data is transferred to Enphase servers every 15 minutes when using wi-fi or ethernet, or every 6 hours when using a cell modem. It's available to installers (thru Enphase cloud software) for troubleshooting. It can help diagnose wire errors, module errors, etc.
The data from micros is transferred to the gateway thru line-to-line Power Line Communication (PLC), at 110kHz. This means the data is transferred on the same conductors that transfer power. (I'm curious about using PLC as a local smart-home-device communication network (instead of wi-fi).)
For island-mode compatibility (when disconnected from the grid), two forms of communication with Enphase servers are required (cellular connection and wi-fi connection).
If an Enphase battery is included, data connection to Enphase servers must be available at least once every 30 days (as required by the battery warranty). Otherwise, a server connection isn't required after commissioning (but is of course strongly recommended by Enphase).
Data was previously transferred between wall-mounted Enphase equipment thru bluetooth and zigbee. Now, data is transferred thru coms wires. The latter is much better. Devices are discovered within 3 minutes, instead of (sometimes) 30 minutes.
Go easy when torquing CTRL (control) cable terminal blocks ("CTRL cable" per NEC 725 (vs. NEC chapter 8)). Only 1.7 inch pounds. A zip tie will provide strain relief.
The maximum acceptable CTRL-cable run is 250'. The CTRL cable has a resistor at each end.
In electrical panels, L1 typically connects to the left terminal. Eaton, Siemens, and GE swap phases (for mechanical reasons, so everything can fit inside). The phase can be tested before installation (with a volt meter). If zero volts, it's the same phase. If 240 volts, it's the other phase.
TC wire or CL3R four-wire security wire can be used to extend consumption CTs (TC wire is better). Use the correct gauge to maintain impedance. Don't use CAT5 (insufficient wire diameter).
Enphase's new CTs are better. Spring clamps. CT torque is 5 inch pounds at the gateway terminal blocks. If CT terminals are over-torqued and damaged, a whole new gateway terminal bus must be installed.
Enphase's system controller has a neutral-forming transformer (NFT).
When the grid fails, the system controller will switch over immediately (fast enough that digital clocks won't have to be reset). But it's not medical-grade certified.
System controller 3 won't support a generator, but will support more batteries (up to 16 batteries / 80 kWh). Controller 3G supports a generator, but fewer batteries.
The system controller is rated for 200 amps. It has an integrated microgrid interconnect device (MID). It has a mechanical relay (which is more trusted than a digital relay). It supports breakers up to 80 amps.
For a Sunlight Backup system with PV only (no battery): The IQ load controller is necessary for PV-power shedding if the PV micros are IQ6 or IQ7.
The 5P battery supports surge power up to 200% of continuous power.
In the system controller, the connections from left to right: First two for load controllers, then the rapid-shutdown device, then the generator.
Rapid shutdown is required for battery backup. The rapid-shutdown switch must be within 10' of the main panel.
In order for the micros to produce power, the system controller must provide a 240-volt 60-hertz grid.
Beyond 8 batteries, more power won't be available. But there will be more "gas in the gas tank" (more energy capacity).
The disconnect can't be over 6' 6" high. The battery can't be within 1' of the ceiling. A 6" gap is required between batteries. Batteries must be at least 3' from ingress / egress (doors, and windows that a person could get through).
Enphase now offers a pedestal mount for 5P batteries.
Bollards are typically 3' apart.
Some AHJs require hard-wired heat detection with an alarm system.
The 5P battery is 145 pounds.
In the new 5P version, the disconnect is on the outside of the box. In the new version, wires can enter from the left, right, or back.
There are new battery lifting handles. They're much better than the old version.
The 5P battery has a 5% reserve, with a 3% reserve under that (0% is a "false bottom"). The reserve supports black starts.
Should always torque to spec in Enphase equipment. One tool option recommended by Jarett is the Capri digital torque screwdriver. The torque requirements are on the inside of the equipment's cover. All Enphase torque specs are in inch pounds.
Enphase uses CAN bus, but refers to it as: command and control wire.
The "drain" wire helps with interference.
Enphase batteries use pouch cells, not cylinder cells.
With the gateway: access point (AP) mode. A long press turns on wi-fi protected setup (WPS) mode. ...To connect without typing in the homeowner's wi-fi password. WPS mode is supported by most routers made in the last 10 years. WPS mode requires pressing a button on the router.
During provisioning and every time the system is restarted, the gateway sends the Rule 21 grid profile to connected Enphase devices.
Per a Rule 21 requirement, power can start exporting to the utility grid within 30 seconds. In other states, it can take up to 5 minutes (to protect lineworkers, etc).
The envoy (gateway) uses around 5 watts (this depends on if it has Cell active).
If the 5P battery light is "breathing" green, it's charging. If it's breathing blue, it's discharging.
If more power is requested than the battery and inverters can provide... this will "collapse the microgrid". It'll reset, and will try to reconnect every two minutes.
The IQ8 micros have built-in PV power shedding (to exactly match loads in off-grid environments). This feature is thanks to an integrated ASIC chip, and 6 years of design effort. It adjusts in milliseconds.
The system has a "storm guard" feature. If there's an alert from NOA (high wind, etc), the system's priority will be charging the battery to 100% (given the higher likelihood of a grid outage).
The inverters and batteries create and maintains a perfect grid... exactly 240 volts and 60 hertz. When the utility grid is available again, the two grids can't just be "slapped together". The Enphase system will gradually transition devices to the imperfect utility-grid voltage and frequency.
The inverters will accept the voltage range: 211 to 264 (or a broader range with a Rule 21 profile).
Enphase has a "limited product upgrade program" (LPUP), for replacing third-party inverters (e.g. SolarEdge) with discounted Enphase inverters.
Those are my notes. It was a good exercise to type them out. Most of my notes die in misc notebooks and paper scraps. And everything that isn't written dies (quickly) in my mind.
Thanks again to Jarret and Enphase for the information-packed training.