Our Glossary is always under Construction!
Alternating Current (AC) A type of electrical current, the direction of which is reversed at regular intervals or cycles. In the Canada and the United States, the standard is 120 reversals or 60 cycles per second. Frequency is expressed in cycles per second (Hertz or Hz). Electricity transmission networks use AC because voltage can be controlled with relative ease.
American Wire Gauge (AWG) A standard system for designation wire diameter. Also referred to as the Brown and Sharpe (B&S) wire gauge.
Capability (AIC) direct current fuses should be rated with a sufficient
AIC to interrupt the highest possible current.
Antimony is added to lead to increase hardness. The high antimony content also reduces long discharge capability and increases the gases produced by the cells during charging.
Blocking Diode A semiconductor connected in series with a solar cell or cells and a storage battery to keep the battery from discharging through the cell when there is no output, or low output, from the solar cell. It can be thought of as a one-way valve that allows electrons to flow forwards, but not backwards.
Bypass Diode A diode connected across one or more solar cells in a photovoltaic module such that the diode will conduct if the cell(s) become reverse biased. It protects these solar cells from thermal destruction in case of total or partial shading of individual solar cells while other cells are exposed to full light
Categorizing Hardness: (divide by 17.2 to get grains per gallon)
Charge Controller A component of a photovoltaic system that controls the flow of current to and from the battery to protect it from over-charge and over-discharge. The charge controller may also indicate the system operational status.
Conductor The material
through which electricity is transmitted, such as an electrical wire, or
transmission or distribution line.
Chlorine Generator By passing a current through brine water chlorine gas is emitted. In the case of a chlorine generator within a water conditioner this chlorine gas can be used to add chlorine and chlorine gas to both sterilize and oxidize the media during a regeneration cycle. Water PH is raised during this process.
Current See electric current.
Cutoff Voltage The voltage levels (activation) at which the charge controller disconnects the photovoltaic array from the battery or the load from the battery.
Diode An electronic device that allows current to flow in one direction only. See blocking diode and bypass diode.
Direct Current (DC) A type of electricity transmission and distribution by which electricity flows in one direction through the conductor, usually relatively low voltage and high current. To be used for typical 120 volt or 220 volt household appliances, DC must be converted to alternating current, its opposite.
DC See direct current.
Hydrogen sulphide gas is the source of the foul "rotten egg" smell and taste. Produced by natural decomposition of underground organic deposits and the action of sulfate reducing bacteria, Hydrogen Sulphide is highly corrosive and can cause damage to well casings, pumps and plumbing fixtures. Hydrogen Sulphide gas is easily detected with your nose. You can smell it in amounts so small that standard tests won't find it.
Sulfur-reducing bacteria, which use sulfur as an energy source, are the primary producers of large quantities of Hydrogen Sulphide. These bacteria chemically change natural sulfates in water to Hydrogen Sulphide. Sulfur-reducing bacteria are anaerobic and live in oxygen-deficient environments such as deep wells, plumbing systems, water softeners and water heaters.
Hydrogen Sulphide often is present in wells drilled in shale or sandstone, or near coal or peat deposits or oil fields. Occasionally, a hot water heater is a source of Hydrogen Sulphide odor. The magnesium corrosion control rod present in many hot water heaters can chemically reduce naturally occurring sulfates to Hydrogen Sulphide. If Hydrogen Sulphide odor is associated primarily with the hot water system, a hot water heater modification may reduce the odor. Replacing the water heater's magnesium corrosion control rod with one made of aluminum or another metal may improve the situation.
A nuisance associated with Hydrogen Sulphide includes its corrosiveness to metals such as iron, steel, copper and brass. It can tarnish silverware and discolor copper and brass utensils. Hydrogen Sulphide also can cause yellow or black stains on kitchen and bathroom fixtures. Coffee, tea and other beverages made with water containing Hydrogen Sulphide may be discolored and the appearance and taste of cooked foods can be affected.
Hydrogen Sulphide gas is flammable and poisonous. Usually it is not a health risk at concentrations present in household water, except in exceptionally high concentrations. While such concentrations are rare, Hydrogen Sulphide's presence in drinking water when released in confined areas has been known to cause nausea, illness and, in extreme cases, death.
Water with Hydrogen Sulphide
alone does not cause disease. In rare cases, however, Hydrogen Sulphide odor may
be from sewage pollution which can contain disease-producing contaminants. Therefore,
testing for bacterial contamination and Sulfate Reducing Bacteria is highly
Hydrogen Sulphide may be temporarily controlled by conducting a shock chlorination / disinfection of the well or water source. Please visit the Shock Chlorination page to get more information on this protocol. If the problem with the well is because of Sulfate Reducing Bacteria, a high level of chlorination, mixing, and turbulence may be needed.
To remove low levels of Hydrogen Sulphide, install an activated carbon filter. The filter must be replaced periodically to maintain performance.
Hydrogen Sulphide concentrations up to about 5 to 7 ppm can be removed using an oxidizing filter. These filters are similar to the units used for iron treatment . This filter contains sand with a manganese dioxide coating that changes Hydrogen Sulphide gas to tiny particles of sulfur that are trapped inside the filter. The sand filter must be backwashed regularly and treated with potassium permanganate to maintain the coating.
Hydrogen Sulphide concentrations exceeding 7 to 10 ppm can be removed by injecting an oxidizing chemical such as household bleach or potassium permanganate followed up by filtration. The oxidizing chemical should enter the water upstream from the storage or mixing tank to provide at least 30- 45 minutes of contact time between the chemical and water. The length of the holding time is a function of the chemical dosage, tank configuration, and water temperature. Sulfur particles can then be removed using a sediment filter and the excess chlorine can be removed by activated carbon filtration. When potassium permanganate is used a manganese greensand filter is recommended.
Inverter A device that converts direct current electricity to alternating current either for stand-alone systems or to supply power to an electricity grid.
Inverter, - Grid Tie or Line-Commutated An inverter that is tied to a power grid or line. The commutation of power (conversion from direct current to alternating current) is controlled by the power line, so that, if there is a failure in the power grid, the photovoltaic system cannot feed power into the line.
Inverter, Utility-Interactive An inverter that can function only when tied to the utility grid, and uses the prevailing line-voltage frequency on the utility line as a control parameter to ensure that the photovoltaic system's output is fully synchronized with the utility power.
Iron is the fourth most abundant element, by weight, in the earth's crust. Taste thresholds of iron in water are 0.1 mg/l for ferrous iron and 0.2 mg/l ferric iron, giving water a bitter or an astringent taste. Water that is high in iron and manganese may have a metallic or medicinal taste. The five forms of iron commonly found in drinking water are:
Water contaminated with ferrous iron appears clear when first drawn at the cold water faucet because the iron is completely dissolved. When ferrous iron is exposed to air, it becomes ferric iron which is red in colour.
Water that is high in iron causes brown-yellow-red stains appear on porcelain fixtures or fixtures where water stands or drips. They also appear on laundry, particularly if chlorine bleach is used.
(kW) A standard unit of electrical power equal to 1000 watts, or to the
energy consumption at a rate of 1000 joules per second.
Manganese is rarely found alone in a water source but is generally found with dissolved iron and acts in a manner similar to iron. Evidence of manganese staining is usually most prominent in the dishwasher. The detergents used to wash the dishes raise the pH of the water high enough (>8) to allow the manganese to precipitate easily. The manganese forms a film that is sometimes mistaken for oil on the water. If you touch the surface of this water the film will break into flakes with jagged edges.
Maximum Power Point Tracking (MPPT) - is system that uses a control algorithm to keep the PV modules operating close to their peak power point while the incoming power level varies.
Nominal Voltage A reference voltage used to describe batteries, modules, or systems (i.e., a 12-volt or 24-volt battery, module, or system).
Ohm A measure of the electrical resistance of a material equal to the resistance of a circuit in which the potential difference of 1 volt produces a current of 1 ampere.
Power Conversion Efficiency The ratio of output power to input power of the inverter.
Power Factor (PF) The ratio of actual power being used in a circuit, expressed in watts or kilowatts, to the power that is apparently being drawn from a power source, expressed in volt-amperes or kilovolt-amperes.
Inverter, Pulse-Width-Modulated (PWM) Wave A type of power inverter that produce a high quality (nearly sinusoidal) voltage, at minimum current harmonics.
Cycles (Battery)- A period of discharge and recharge is called one cycle. Battery performance may be measured by the expected number of cycles it may deliver at varying depths of discharge.
Discharge Rate The rate, usually expressed in amperes or time, at which electrical current is taken from the battery.
Disconnect Switch gear used to connect or disconnect components in a photovoltaic system.
Depth of Discharge (DOD)- is the ratio of amp hours removed from a battery versus its full capacity. For example 25 Ah are removed from a 100 Ah battery, thus it's depth of discharge is 25% and the battery is at a 75% state of charge.
Electrolyte A nonmetallic (liquid or solid) conductor that carries current by the movement of ions (instead of electrons) with the liberation of matter at the electrodes of an electrochemical cell.
Equalization Charge The process of mixing the electrolyte in batteries by periodically overcharging the batteries for a short time. A continuation of normal battery charging, at a voltage level slightly higher than the normal end-of-charge voltage, in order to provide cell equalization within a battery.
Float Charge The voltage required to counteract the self-discharge of the battery at a certain temperature.
Gassing Current The portion of charge current that goes into electrolytical production of hydrogen and oxygen from the electrolytic liquid. This current increases with increasing voltage and temperature.
Gel-Type Battery Lead-acid battery in which the electrolyte is composed of a silica gel matrix.
Line-commutated Inverter - Grid tie inverters use the grid to set frequency.
Liquid Electrolyte Battery A battery containing a liquid solution of acid and water. Distilled water may be added to these batteries to replenish the electrolyte as necessary. Also called a flooded battery because the plates are covered with the electrolyte.
Maintenance-Free Battery A sealed battery to which water cannot be added to maintain electrolyte level.
Module Integrated Inverter (MIC) - are tiny inverters designed for use with a single large module.
Multi-string inverter - is a recent development. This is where one inverter unit has multiple MPPT and DC-DC converter units each connected to a string of modules. Shading and mismatch losses are again reduced but only one inverter is required.
Nickel Cadmium Battery A battery containing nickel and cadmium plates and an alkaline electrolyte.
Nominal Voltage A reference voltage used to describe batteries, modules, or systems (i.e., a 12-volt or 24-volt battery, module, or system).
Overcharge Forcing current into a fully charged battery. The battery will be damaged if overcharged for a long period.
Plates A metal plate, usually lead or lead compound, immersed in the electrolyte in a battery.
Pulse Width Modulation - is used to generate a waveform as close as possible to a sine wave. Pulses of different voltages are generated and the width of the pulse is modified so that the resulting wave is as close as possible to a sinusoidal wave form
Rated Battery Capacity The term used by battery manufacturers to indicate the maximum amount of energy that can be withdrawn from a battery under specified discharge rate and temperature. See battery capacity.
Rated Module Current (A) The current output of a photovoltaic module measured at standard test conditions of 1,000 w/m2 and 25�C cell temperature.
Rectifier A device that converts alternating current to direct current. See inverter. Rated Power Rated power of the inverter. However, some units can not produce rated power continuously. See duty rating.
Regulator Prevents overcharging of batteries by controlling charge cycle-usually adjustable to conform to specific battery needs.Rectifier A device that converts alternating current to direct current. See inverter. Rated Power Rated power of the inverter. However, some units can not produce rated power continuously. See duty rating.
Reverse Current Protection Any method of preventing unwanted current flow from the battery to the photovoltaic array (usually at night). See blocking diode.
Self Commutated - Most modern inverters are self-commutated, they set their own frequency rather than relying on the grid to provide the frequency as a line-commutated inverter does.
Series Connection A way of joining battery or photovoltaic cells by connecting positive leads to negative leads; such a configuration increases the voltage.
Shock chlorination There is a chance of bacterial contamination any time there is a new well or a water system fixture such as a pump is removed from a well and replaced. Bacterial problems are most common in shallow wells and areas with coarse textured soils and fractured bedrock or limestone. The major source of contamination is surface water, or septic tanks or sewage lines located too close to the well. Runoff or leaching from livestock operations can also contaminate wells.
Test the water for bacteria two weeks after shock chlorination to see if you have a recurring problem. Contact your local Health Department for information on water testing and well protection.
Shock chlorination can be done using ordinary laundry bleach (containing approx. 5.25 percent sodium hypochlorite right out of the jug) or calcium hypochlorite (containing 65%-75% available chlorine). The goal is to add enough chlorine to raise the chlorine concentration in the well to about 200 milligrams per liter to kill potentially harmful bacteria and viruses.
A thorough shock chlorination of the well and water system may destroy all iron bacteria colonies. However, if iron bacteria have penetrated the water-bearing formation they will be difficult to eliminate and will likely re-infest the system. In this situation you will need to repeat chlorination treatment periodically.
Short-Circuit Current (Isc) The current flowing freely through an external
circuit that has no load or resistance; the maximum current possible.
Single-Stage Controller A charge controller that redirects all charging current as the battery nears full state-of-charge.
Wave A waveform that has only two states, (i.e., positive or negative). A
square wave contains a large number of harmonics.
Standby Current This is the amount of current (power) used by the inverter when no load is active (lost power). The efficiency of the inverter is lowest when the load demand is low.
String inverters - is where a number of inverters are used, each receiving input from a single string of modules. This concept introduced by SMA with their Sunnyboy range and string inverters quickly came to dominate the market for domestic scale PV systems
Surge Capacity The maximum power, usually 3-5 times the rated power, that can be provided over a short time.
System Operating Voltage The photovoltaic array output voltage under load. The system operating voltage is dependent on the load or batteries connected to the output terminals.
Loss caused by a charge controller. One minus tare loss, expressed as a
percentage, is equal to the controller efficiency.
Total AC Load Demand The sum of the alternating current loads. This value is important when selecting an inverter.
Varistor A voltage-dependent variable resistor. Normally used to protect sensitive equipment from power spikes or lightning strikes by shunting the energy to ground.
A unit of electrical force equal to that amount of electromotive force that will
cause a steady current of one ampere to flow through a resistance of one ohm.
In other words, Volts is the measure of the force that each electron is under.
Voltage Disconnect HIGH - The voltage at which a charge controller will disconnect the load from the batteries to prevent over-discharging.
Voltage Disconnect Low - The voltage at which a charge controller will disconnect the photovoltaic array from the batteries to prevent overcharging.
The rate of energy transfer equivalent to one ampere under an electrical
pressure of one volt. One watt equals 1/746 horsepower, or one joule per second.
It is the product of voltage and current (amperage).
Watt-hour - is a unit of energy, electrical energy, equal to the work done by one watt acting for one hour.
The shape of the phase power at a certain frequency and amplitude.
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