Can I use a datasheet from a similar module?

No. Use the exact module model and revision where possible because voltage values and coefficients can differ.

Why does the sign of the coefficient matter?

PV voltage temperature coefficients are often negative. Entering the sign incorrectly can move cold and hot voltage results in the wrong direction.

PV module data sheet inputs

Datasheet purpose

PV voltage calculators are only as strong as the product data entered. The module datasheet should supply the voltage values and coefficients used for cold Voc and operating-voltage checks.

This guide helps collect data before the calculation starts.

Workflow

Identify the exact module model and datasheet revision.
Record Voc and Vmp at STC.
Record the voltage temperature coefficients and unit convention.
Record module count and string reference from the design.
Keep inverter limit fields separate until the string-voltage calculation is run.

Datasheet table

PV module input fields
Field	Record	Review concern
Module model	Exact product name	Similar models can differ
Datasheet revision	Date or revision source	Values can change by version
Voc and Vmp	STC voltage values	Used directly in voltage formulas
Voltage coefficient	Percent per deg C or equivalent	Sign and unit must be checked
Module count	Series modules in string	Must match the physical design

Boundaries

Do not use wattage alone to identify a module.
Do not use power coefficient in place of voltage coefficient.
Do not hide datasheet revision or product source.
Do not move to inverter compatibility review until input sources are clear.