PV System Sizing Principles

Question 1

A crystalline silicon PV array that has bipolar outputs of +252V and -252V with a common grounded conductor under STC is selected for a large single-family residence. For this system, if the maximum system voltage is close to 605V, what is the lowest expected temperature at the installation site?

Answer 1

-25 degrees Fahrenheit

Question 2

Subpart E of OSHA PART 1926 describes regulations regarding…

Answer 2

OSHA Rules for personal protection and life-saving equipment

Question 3

What should be connected on the side of a battery between two batteries?

Answer 3

The charge controller battery temperature sensor

Question 4

What does a transformer do?

Answer 4

Transforms radio waveforms in frequency applications; transforms amperage; transforms voltage, and/or transforms current

Question 5

System availability is the percentage of what?

Answer 5

Average time percentage per year a stand-alone PV system meets its load requirements

Question 6

Are 110 volts, 120 volts, and 240 volts, two phase?

Answer 6

No

Question 7

True or False: Ohm’s law states that an increase in current is inversely proportional to an increase in voltage.

Answer 7

FALSE

Question 8

Ampacity is determined by what?

Answer 8

Wire width

Question 9

What are the only inverters that have low harmonic distortion?

Answer 9

Sine waves inverters, since they are required for connection to utility lines

Question 10

What electrical property increases on a hot day?

Answer 10

Voltage drop

Question 11

If a cold front moves in, what will increase?

Answer 11

The voltage of a PV system

Question 12

Where are the OSHA Rules for personal protection and life-saving equipment found in OSHA PART 1926?

Answer 12

Subpart E

Question 13

If the output of the inverter is connected to the optional standby system panel through a 30 A circuit breaker, what is the appropriate size of the equipment grounding conductor between the inverter and the emergency panel?

Answer 13

10 AWG copper

Question 14

What starts at the load size and ends at the array?

Answer 14

System sizing

Question 15

According to the NEC, if flooded lead-acid batteries are selected for energy storage for a PV system, the battery enclosure must have what?

Answer 15

Provisions for sufficient diffusion and ventilation of the gases from the battery to prevent the accumulation of an explosive mixture, and if a tray is used it shall be resistant to deteriorating action by the electrolyte.

Question 16

Where should the charge controller battery temperature sensor be connected?

Answer 16

The sides between two batteries

Question 17

PV module and determining the array configuration based on the current and voltage parameters is selected when?

Answer 17

During the final step of the sizing process

Question 18

What is the term for the percentage of time that a stand-alone PV system meets its load requirements in an average year?

Answer 18

System Availability

Question 19

The inverter should not supply power to the terminals connected to utility point-of-connection in the event of what?

Answer 19

In the event that the utility voltage is lost in a utility-interactive system that has battery backup and an optional standby system AC distribution panel, and if the inverter is programmed in the sell mode

Question 20

Considering ohms laws, on what type of day do PV watts decrease because of the relationship of volts to watts?

Answer 20

On a cloudy day

Question 21

What do interactive systems offer?

Answer 21

Relatively simple calculations and allow the widest variance in component sizing

Question 22

What is used to size the PV system during the critical design month in the worst case scenario?

Answer 22

Insolation data

Question 23

What system offers relatively simple calculations and allows the widest variance in component sizing?

Answer 23

Interactive system

Question 24

Where (which axis) is I on an I-V curve?

Answer 24

I is on the vertical y-axis

Question 25

The appropriate size and material of the equipment grounding conductor between the inverter and the emergency is 10 AWG copper, the output of the inverter is connected to the optional standby system panel through a _____ circuit breaker.

Answer 25

30-A

Question 26

What is the measure of rate?

Answer 26

Amperes

Question 27

When are the load and the insolation data used to size the PV system?

Answer 27

During the critical design month in the worst case scenario