Stringing & Optimizers

Clearances

Ensure proper heat dissipation around Power Optimizers by keeping the clearance requirements:

Back side (the metal plate): 0 inches
Front side (the black heatsink): 0.5 inches
All other sides: 0.4 inches

Identify Power Optimizer's Output Cables

To locate Power Optimizer's output cables, look for:

The word STRING on the rubber terminal of the S-Series Power Optimizers;
The + OUT - indication on the plastic case bottom of the S-Series and P-Series Power Optimizers

Connect Power Optimizers Output Cables to Form a String

To form a string with the serial connection:

For S-Series Power Optimizers, connect the long output cable of a Power Optimizer to the short output cable of the next Power Optimizer
For P-Series Power Optimizers, connect the long output cable of a Power Optimizer to the long output cable of the next Power Optimizer

While connecting, make sure that all the connectors are firmly inserted and locked.

Connect Power Optimizers Input Cables to PV Modules

To locate Power Optimizer's input cables, look for:

The word MODULE on the rubber terminal of the S-Series Power Optimizers;
The - IN + indication on the plastic case bottom of the S-Series and P-Series Power Optimizers

INSTALLER NOTE: Before using an extension cable, double-check the output cable polarity at the end of the string. The polarity is written on the plastic case bottom of a Power Optimizer (indicated by + OUT -), and not on the Power Optimizer's connector.

To avoid confusion and mistakes, we recommend using a red extension cable if the string ends on positive and a black cable if the string ends on negative.

Installer best practices

Verify connectors are firmly inserted and locked

The MC4 connectors are IP68 compliant and provide a waterproof, dustproof, electrically safe connection once they're firmly inserted and locked.

How do you know if you connected them properly? Just listen to the click!

Use the seal cover for open connectors

If you don’t connect some of the connectors immediately, close them with the seal cover.

Particularly if you leave them overnight, and/or in wet conditions, such as rain, snow, fog, and dew. This simple action will prevent an isolation fault.

Note: Cutting the Power Optimizer’s input or output connectors is prohibited and will void the warranty.

TROUBLESHOOTING

The output voltage of the Power Optimizer that is connected to the PV module, but not connected to the inverter is ≈ 1V. Accordingly, the voltmeter's reading should match the number of Power Optimizers in the string. For example, if you have 16 Power Optimizers in a string, a voltmeter measurement should be ≈ 16V.

If you measure the output voltage of the Power Optimizer and are getting 0V on both panels that is connected to the optimizer then you can safely assume that the optimizer is bad and needs to get RMA'd

Note: If you use extension cables between Power Optimizers, always measure the homerun cable before you connect it to an inverter. Voltmeter readings should reflect the number of Power Optimizers and should be positive. If voltmeter readings are negative and you encounter the reverse polarity issue and you should check your extension cables.

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