Solar/invertors Flashcards
What are the three types of investors?
True sine wave
Modified sine wave
Square sine wave
Which inverter is the closest to an actual AC sine wave?
True sine wave inverters
How does a true sine wave inverter work?
Uses transistors that switch very rapidly.
How is the modified sine wave produced?
It’s produced by introducing an “off” time between the alternating polarities
How are the inverters sized?
Sized to the customers AC load demands
What is the minimum an inverter can be sized to
Sized to the demand from the largest single AC load
What’s the maximum recommended battery cable run for a large inverter?
10’ max combined power and ground
What two things need to be isolated during inverter operation?
The DC converter and the fridge
What should be the circuit protection be for the inverter
200-400amp dude
Where should the control panel be installed?
Should be installed in a protected location that is convenient for the customer to access
What is the efficiency of the newer inverters?
90%
How many amp/hrs should the battery bank be capable of supplying?
Twice the calculated amount/hrs
What is the common gassing point of a deap cycle wet cell battery?
At 25C the gassing point is about 14V
What happens when a wet cell battery isn’t brought to it gassing point during charging?
The surface is left on the plates and deterioration of the battery begins
True or false?
All batteries should be brought up to their gassing point to properly charge?
FALSE!
AGM and GEL cell batteries must not be charged to their gassing point as it will be harmful to the battery
How do you charge an AGM or GEL cell battery?
With a lower bulk charge voltage and a higher float voltage than a wet cell battery
What are the 4 stages of a multi-stage charging system?
Bulk
Equalization
Absorption
Float
What is a BULK charge?
A charge that gets as much current into the battery as fast as possible without damaging the battery
What is the ABSORPTION charge?
Where voltage stays at 14.5V but current will slowly drop as the battery resistance increases
What is the FLOAT charge?
This stage will keep the battery “full” but prevent gassing
What is the basic purpose of a solar charging system?
To provide a potential source of DC power when sunlight is present
What are the 4 components of a solar charging system?
Solar array
Regulator
Battery or battery bank
Conductors (wiring)
What is the most important part of the solar panel? And what do they do?
Silicon cells. It’s a non-metal with conductive properties that give it the ability to convert sunlight into electricity
What are the three types of silicon?
Single cell (monocrystalline)
Polycrystalline
Amorphous
What is the efficiency and life expectancy of the monocrystalline panel
High efficiency (approx 12-16%) Longest life (25-30)
What is the efficiency of polycrystalline?
Approx 11-12%
Which type of silicon is the most susceptible to output loss does to heat?
Polycrystalline
Which type of silicon is:
Blue:
Black:
Brown:
Blue is polycrystalline
Black is crystalline
Brown is amorphous
How efficient is amorphous?
6-8%
When is amorphous generally used?
On calculators, trickle charge, or flexible panels
What is added to the front of a solar panel to add durability and protection for the silicon
Glass
What is the cell count of a high voltage panel?
60 cells at 0.53-0.54 volts/cell
What is the cell count of a convention solar panel
36 cells at 0.5 volts/cell
What’s the cell count of a self-regulating panel?
30-33 cells at 0.48 volts/cell
What regulator do you need to use on a high voltage panel?
An MPPT ( multi power point tracker)
What regulator do you need to use on a conventional solar panel?
A PWN (pulse width modulation) controller to reduce the voltage to 14.5V
How is a solar panel rated?
In peak wattage at 24C and 1000watts per square meter of solar radiation
What is the rate of loss due to temp?
0.4 volts for every 5C change above 27C
What is the purpose of a charge controller?
To protect the batteries from overcharging
What should you use to clean a solar panel?
Use a mild detergent and soft cloth
