©
2017 Sensata Technologies
Page 50
Appendix D – Inverter/Charger Terminology
Locked Rotor Amps
– The current drawn by an electric motor with the shaft or rotor stopped
and locked in position. This can be used to determine if an inverter has enough surge current to
start a motor. If the inverter is capable of producing more amperage than the locked rotor amps
rating of a motor, it will most likely start the motor easily.
NEC (National Electric Code)
– The guidelines and acceptable practices for electrical installations
in the USA.
Off Grid
– Not connected to public power in any way.
Pass Through Current
– The amount of current the inverter can safely pass directly from the
AC input to the AC output.
Photovoltaic (PV)
– Solar powered.
Resistance
(Ohms)
– Slows the electrical
fl
ow of Direct Current (DC)
RMS (Root Mean Square)
– A measure of AC voltage that provides the equivalent heating
value across a resistor as would a DC source of the same voltage.
Sellback,
or
Selling Back To The Grid or Utility-Interactive
– Some inverters have the
capability to take energy stored in batteries, or from solar panels, and put it back into the utility
grid. The local public utility company can compensate you for using this energy.
Shorepower
– The process of providing shore-side electrical power to a boat while its main
and auxiliary engines are turned off. The source for shorepower may be grid power from an
electric utility company, or from an external remote generator.
Stacking:
• Series
– Two inverters operating together to produce twice the power and voltage of a
single inverter. Required when operating 240 VAC loads and separate 120 VAC loads from
either inverter.
• Parallel
– Two inverters operating together to provide twice the continuous capacity on a
single output circuit. Required when a single load is too large for one inverter.
Stratifi cation
– Over time, a battery’s electrolyte (liquid) tends to separate. The electrolyte at
the top of the battery becomes watery while at the bottom it becomes more acidic. This effect is
corrosive to the plates.
Sulfating
– As a battery discharges, its plates become covered with lead sulfate. During
recharging, the lead sulfate leaves the plates and recombines with the electrolyte. If the lead
sulfate remains on the plates for an extended period of time (over two months), it hardens, and
recharging will not remove it. This reduces the effective plate area and the battery’s capacity.
Temperature Compensation
– Peak available battery voltage is temperature dependent. As
ambient temperatures fall, the proper voltage for each charge stage needs to be increased. A
Battery Temperature Sensor (BTS) automatically re-scales charge-voltage settings to compensate
for ambient temperatures.
Voltage
– The pressure that causes electrical
fl
ow in a circuit.
Watts
– Measure of power output or utilization. Watts = Volts x Amps.
