NABCEP Practice Exam

NABCEP Practice Exam If an array is facing south at equinox at noon, what must the tilt angle be in order for the array to face directly at the sun at latitude 30? - ANS - A. 33 degrees B. 48 degrees C. 18 degrees D ...

NABCEP Practice Exam If an array is facing south at equinox at noon, what must the tilt angle be in order for the array to face directly at the sun at latitude 30? - ANS - A. 33 degrees B. 48 degrees C. 18 degrees D. 30 degrees The temperature rating of the insulation of a conductor when designing a PV system effects the - ANS - A. ability of the wire to withstand fire B. ability of the wire to withstand smoke C. ability of the wire to carry current D. ability of the wire to withstand physical damag When a bypass diode kicks in from a leaf on a solar cell, which parameter would you see reduced on a single string with string level MPPT? - ANS - A. Current B. Voltage C. Ohms D. Amp hours Given a PV module with the following characteristics, what would be the expected output at Standard Test Conditions if the inverter and PV were working perfectly and sending power to the grid? 20 in series 1 PV source circuit Voc = 44V Vmp = 35.2V Power = 305W Isc = 9.27A - ANS - A. 704V and 8.66A B. 600V and 8A C. 1000V and 8.2A D. 700V and 9.27A Which is the best and safest way to determine current in a PV output circuit? - ANS - Clamp on ammeter A remote cabin uses the loads below per day, how much total energy is used per day? 1000W toaster for 6 minutes 1.2kW hot water heating element for 3 hours per day Three 17W LED lights for 3 hours per day iPhone 100 charger at 20W for 3 hours per day - ANS - 3.9 kWh What is "blocking" used for? - ANS - Attaching to a roof in a place where there is no rafter If you are going to work on the roof to fix a ground fault and the dc disconnect is on the ground level, which of the following is the best safety procedure? - ANS - e roof B. Removing the GFCI fuse before going on the roof C. Leaving the disconnect in the on position D. Lockout Tagout Who makes requirements for electrical safety for employees? - ANS - OSHA Typical utility interactive systems in the US will - ANS - Export to the utility extra power for credit A PV system that would produce 7kWac under STC conditions, which is not clipping power is installed in a location with an average of 6PSH (peak sun hours, aka kWh/square meter per day average) would produce how much energy in one year? - ANS - 15,330 kWh When PV modules are tested by CSA to the UL 1703 standard, they are tested among other things for - ANS - Fire safety If and inverter indicates that there has been a ground fault, what is the first thing that a O&M technician should do? - ANS - Open all the disconnects If doing an energy audit, which device is the best to replace to conserve energy? - ANS - New resistance heater When handling PV modules on a roof in sunlight, what is the most common method of safety of the following? - ANS - Make sure that connectors are open Which of the following is the worst design flaw when an inexperienced person designs a PV system? - ANS - Multiple orientations within a PV source circuit Part of the process of turning silicon into a solar cell is called? - ANS - Doping How do residential rooftop mounting systems typically attach to a rooftop, so that they do not fly away when the wind blows? - ANS - Lag screws into rafters or purlins What is the shape of a typical monocrystalline solar wafer? - ANS - Square with rounded corners What is the largest array size of the following if you are using a 24V battery bank and a 20A charge controller? - ANS - 280W Which of the following is able to change dc power into ac power with a predetermined specific frequency and voltage? - ANS - Inverter What color wires can be used for equipment grounding (earthing is international term) wires in the US? - ANS - Green, bare or green with yellow stripe What does MPPT stand for? - ANS - Maximum power point tracking Which is the best solution of the following for multiple orientations when designing a PV system? - ANS - Microinverter If you want to use modules that are dissimilar and in multiple orientations, what is the best type of system to use? - ANS - Dc-to-dc converter (power optimizer) system In the western part of the USA and Canada, what direction does the north arrow of a magnetic compass point? - ANS - East of north You are rebuilding an old battery system for a PV museum and everything is in amps and amp hours. You are told that the system needs to have 33% more PV production on average than what the loads require. The loads will require 20Ah per day and the insolation will be 5PSH. If the module current at STC is 8A at Imp and 9A at Isc, how many PV source circuits would be needed to meet the minimum requirements stated here? - ANS - 1 Which tilt angle from horizontal would get the best annual production from a location in Toronto at 43 degrees north? - ANS - 42 degrees A multimodal inverter that has an internal automatic transfer switch would have to monitor what in order to transfer to backup power? - ANS - Primary power source voltage Which of the following will have the highest voltage setting for charging flooded lead acid batteries? - ANS - Equalization charge Besides calculations, where can we find out what would be the maximum series fuse rating of a PV module? - ANS - On the back of the module Is there a difference between solar noon and noon as most people know it and if so, what is the difference? - ANS - Solar noon is not dependent on time zones What contributes to determining the ampacity or the temperature rating of a conductor? - ANS - Insulation The definitions of the difference of a PV output circuit and inverter input circuit for a grid-tied system are very similar and some believe overlap. In many diagrams, what is the point where the PV output circuit becomes an inverter input ci