I installed the Beacon SmartPower M5 Plus inverter this passed summer for one of my customer's in the upstate NY region.

The system consisted of:
28 Shell 165W Panels wired in 14 strings of 2 for 4620W at 89.0VDC & 5.4A Isc.

The battery bank consisted of two strings of 4 batteries each for 516Ah @ 48VDC

The beacon inverter was easy to install. Like every inverter I wish there was more room in the wiring cavity because I used the maximum wiring sizes permitted to avoid voltage drop.

The main difference between the M5 and M5 plus is a nice LCD panel on the front of the unit. It is invaluable. It would be hard to know what the unit is doing unless you had the LCD display. The display is installed at the factory and as far as I know is not field upgradeable.

The only caveat to installing this inverter is that you have to AC connections. One connection is the "sell back" wire which connects to the main AC panel and is used to sell back excess power and monitor the grid power for blackouts/brownouts/surges as appropriate to UL1741.

The second AC connection is the "LOAD" connection. Which usually connects to a subpanel and will allow the unit to power "critical" loads in the event of a grid failure from your battery bank. MAKE SURE YOU INSTALL A 3-WAY SWITCH HERE SO THAT YOU CAN POWER THE SUBPANEL FROM THE GRID IN THE EVENT THAT YOU NEED TO EITHER POWER OFF THE INVERTER OR DISCONNECT THE INVERTER FOR SERVICING/TESTING. Or just don't populate your subpanel until your inverter is fully installed and working and your utility has approved you interconnection.

The unit also came with Beacon's PC software for monitoring the unit for datacollection. Although some of the advanced features require technical support to enable them. The software came free with the M% Plus and there was no extra hardware required. The RS-232 interface came standard on the M5 Plus.

Commissioning the system was easy. Beacon provides a shortcut of the order that circuit breakers need to be turned on (and off) on the cover of the inverter.

The inverter is pretty quiet. The fans don't come on until there is about 4000W of PV input.

The unit is quite easy to mount. It comes with a standard metal plate that must be secured properly to your mounting surface. And then it does require two people to lift the unit and hang it on the bracket. Then the unit is screwed down to prevent it from falling off the bracket.

The unit requires all wiring to enter via the bottom. The bottom plate is removeable so that conduit holes can be cut properly. Drilling the plate at the bottom when the plate is still installed in the unit voids the warranty due to the fact that they don't want metal shavings to get inside the unit.

Overall the customer has been very happy with their unit and it has performed up to expectations. It seems to be very efficient and topping off the batteries with a slow trickle charge does not seem to degrade the overall power output.

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