Hi all you solar experts. I was looking at a 5 kw solar power center that requires 90 volts from the panels to "start". I have never heard of this anywhere except for this one product.
Has anyone else heard of this? Here is the product in question
Not at all uncommon. The furnished MPPT controllers (two ?) require that you maintain a PV input voltage much greater than the nominal system voltage (evidently 48 vdc). As an example, to develop 5kW output from a solar array using 250 watt 24v panels, you might be asked to configure your panels in two separate circuits (two MPPT controllers @ 2.5 kW ea.) . Maybe each circuit will contain about 12 panels in a series/parallel arrangement which does not exceed the 150vdc maximum input voltage limitation but does (must) operate at greater than 90vdc.
Until you have sufficient panel illumination to furnish 90vdc to the MPPT controller(s), you will not have power delivered to your storage. The beauty of the MPPT controller is that the higher voltage input from your panels is converted to very useful levels of current and voltage in order to maintain the batteries.