CyberPower CPSPV4000ETL User Manual Download Page 5

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Installation

PV Array Requirement

WARNING! Shock hazard

Whenever a PV array is exposed to sunlight, a shock hazard exists at the
output wires or exposed terminals. To reduce the risk of shock during
installation, cover the array with an opaque (dark) material before making
any connections.

IMPORTANT:

The PV array should be free of shade. This requirement includes even
small obstructions such as vent pipes, chimneys and power lines. A small
amount of shade can have a disproportionately high impact on system
performance.

General Recommendations

It is important that the PV array is installed correctly to the manufacturer
specifications and to local code requirement.

Equipment and Installation Recommendation
Equipment recommendations

All electric equipment should be listed for the voltage and current
ratings necessary for the application.

All wiring should be sized correctly to minimize voltage drop.

All required over-current protections should be include the system
and accessible for maintenance.

Integral roofing products should be properly rated.

Installation recommendations

All electrical terminations should be fully tightened, secured, and
strain relieved as appropriate.

All mounting equipment should be installed according to the
manufacturer specifications.

All roof penetrations should be sealed with an acceptable sealing
method that does not adversely impact the roof warranty.

All wires, conduit, exposed conductors and electrical boxes should
be secured and supported according to code requirements.

PV Voltage and MPPT Requirement

MPPT operational window

The MPPT software maximizes the output energy of solar arrays as long
as the operating voltage is within the operational window. Ensure that the
PV array used in the system operates within the MPPT operational
window. Effects of array voltages outside of the MPPT operational
window are shown in below Table.

Vol tage

(Vd c)

Effec t o f Arr a y Vol tag e

Inve rter Mod e

<250

Will shut down

Shutdown

250~310

Maximum harvest of solar energy. (limit

input max current 17A)

MPPT window

310~750

Maximum harvest of solar energy.

MPPT window

750~900

Maximum harvest of solar energy. (limit

input max power)

MPPT window

>900

Will shut down and may cause damage

to the inverter.

Shutdown

PV Voltage requirements

The maximum power point voltage of a string connect to the inverter
should be a minimum of 320Vdc. If it is less than 320Vdc, the inverter will
continue to operate, but it will regulate the PV voltage to 320Vdc.
Because the array will not be operating at its maximum power point, this
may result in lower than expected energy harvest.

Maximum PV Power

The solar array should be sized such that the maximum power output
dose not exceeds the limit of the MPPT operation window. The array
voltage should never exceed 900 VOC (open circuit voltage) under any
thermal condition. Likewise, ensure that ISC (short circuit current) rating
of the array at any temperature does not exceed the short circuit current
of the inverter.

Guideline for Matching PV Array Size to Solar Inverter Input

For determining the number of panels required in the PV string (panels
connected in series), you must ensure that the following requirements are
met:

To avoid damage to the inverter, ensure that PV array output will
never exceed 900Vdc under any conditions.

Do not exceed the maximum array short circuit current rating
marked on the inverter.

To achieve maximum energy harvest from your array, ensure that
the V

(voltage at maximum power) dose not drop below 310Vdc

under most condition.