Samlexpower PST-300-12 User manual

DC-AC Power
Inverter
Pure Sine Wave
PST-300-12
PST-300-24
Please read this
manual BEFORE
installing your
inverter
Owner's
Manual

2 | SAMLEX AMERICA INC.
SECTION 1 | Safety Instructions
The following safety symbols will be used in this manual to highlight safety
and information:
WARNING!
Indicates possibility of physical harm to the user in case of non-compliance.
!CAUTION!
Indicates possibility of damage to the equipment in case of non-compliance.
iINFO
Indicates useful supplemental information.
Please read these instructions before installing or operating the unit to prevent personal
injury or damage to the unit.
SAFETY INSTRUCTIONS - GENERAL
Installation and wiring compliance
 
must be done by a certied electrician.
Preventing electrical shock
 
system.
 
 
with the unit. Turning the  switch on the unit to OFF position may not entirely
remove dangerous voltages.
 


Installation environment
 
environment
 
 
openings of the cooling fans.
 

SECTION 1 | Safety Instructions
Preventing re and explosion hazards
 
in areas where there are ammable materials or gases requiring ignition protected


Precautions when working with batteries
 

 

the battery manufacturer’s recommendations.
 
 

 
The batteries can produce a short circuit current high enough to weld a ring or the

 

SAFETY INSTRUCTIONS - INVERTER RELATED
Preventing Paralleling of the AC Output




damage the output section of the unit and may also pose a re and safety hazard. If an



Selector Switch and the output of the Selector Switch should be connected to the Elec-

!CAUTION!



Preventing DC Input Over Voltage


4 | SAMLEX AMERICA INC.
SECTION 1 | Safety Instructions

damage to the unit. Please observe the following precautions:
 -


 


controller between the solar panel and the battery.
 -


Preventing Reverse Polarity on the Input Side
-



also cause permanent damage to the inverter.
!CAUTION!


SECTION 2 | General Information


Peak Value:
RMS (Root Mean Square) Value: It is a statistical average value of a quantity that varies



Voltage (V), Volts:

-

Current (I), Amps, A:

Frequency (F), Hz: It is a measure of the number of occurrences of a repeating event per

Efciency, (η):
Phase Angle, (φ): It is denoted by “φ
current vector leads or lags the voltage vector in a sinusoidal voltage. In a purely induc-
φ
φ

φ-
φ
and may lag or lead the voltage vector.
Resistance (R), :It is the property of a conductor that opposes the ow of current
-
age. It is denoted by "R" and its unit is "Ohm" - also denoted as "".
Inductive Reactance (XL), Capacitive Reactance (XC) and Reactance (X): Reactance is the
opposition of a circuit element to a change of electric current or voltage due to that
element's inductance or capacitance. Inductive Reactance (XL
of wire in resisting any change of electric current through the coil. It is proportional to
frequency and inductance and causes the current vector to lag the voltage vector by
φXC
oppose changes in voltage. XCis inversely proportional to the frequency and capacitance
φ
unit of both XLand XCis "Ohm" - also denoted as "". The effects of inductive reac-
tance XL-
tance XC

6 | SAMLEX AMERICA INC.

Reactance (X) will be equal to the difference between the
values of the inductive and capacitive reactances. The net Reactance (X) will be inductive
if XLXCand capacitive if XCXL.
Impedance, Z: It is the vectorial sum of Resistance and Reactance vectors in a circuit.
PPWatt

Power for powering the inductive and capacitive elements. The effective power required

Reactive Power (Q), VAR: Is denoted as “QVAR
is alternatively stored and returned by the inductive and capacitive elements of the load.
It is not consumed by the inductive and capacitive elements in the load but a certain




Hence, the inverter, AC wiring and over cur-
rent protection devices have to be sized based on the combined effect of the Active and
Reactive Powers that is called the Apparent Power.
Apparent (S) Power, VA:

Please note that
Apparent Power VA is more than the Active Power in Watts. Hence, the inverter, AC wir-
ing and over current protection devices have to be sized based on the Apparent Power.
Power Factor, (PF):





Load: Electrical appliance or device to which an electrical voltage is fed.
Linear Load: 

Non-Linear Load:-


Resistive Load:

SECTION 2 | General Information


creating overload.
Reactive Load:-
-


The inverter has to be sized based on the higher Apparent
Power (VA).
Output Voltage Waveforms
Fig. 2.1: Pure and Modied Sine Waveforms

waveform of the grid power. Please see sine wave represented in the Fig. 2.1 that also
shows modied waveform for comparison.






modied sine waveform.




SECTION 2 | General Information
TIME
180
160
140
120
100
80
60
40
20
0
20
40
60
80
100
120
140
160
180
Modied Sine
Wave sits at
ZERO for some
time and then
rises or falls
Modied Sine Wave
Sine Wave
Pure Sine Wave
crosses 0.0V
instantaneously

8 | SAMLEX AMERICA INC.
SECTION 2 | General Information
frequency harmonic content in a modied sine wave produces enhanced radio interfer-


frequency harmonics also produce overloading effect in low frequency capacitors due to
lowering of their capacitive reactance by the higher harmonic frequencies. These capaci-
tors are used in ballasts for uorescent lighting for Power Factor improvement and in

wave inverters may shut down due to overload when powering these devices.
Advantages of Pure Sine Wave Inverters
 

 
and cooler.
 
improvement capacitors and single phase motors containing start and run capacitors
 

 
glitches in monitors.
Some examples of devices that may not work properly with modied sine
wave and may also get damaged are given below:
 
 -

 

 
 

tools. These may get damaged. Please check with the manufacturer of these types of
devices for suitability.
 
 
 These may get damaged.
Please check with the manufacturer of these types of devices for suitability.
 
The inverter may shut down indicating overload.

Power Rating of the Inverters





-

-



repeated overloading.
iINFO
The manufacturers’ specication for power rating of the appliances and devices
indicates only the running power required. The surge power required by some
-







TABLE 2.1: INVERTER SIZING FACTOR
Type of Device or Appliance
Inverter
Sizing Factor*
 
 4
 3
 3
 2
Furnace Fan 3
Industrial Motor 3
 3
 3
 3
►
SECTION 2 | General Information

10 | SAMLEX AMERICA INC.
TABLE 2.1: INVERTER SIZING FACTOR
Type of Device or Appliance
Inverter
Sizing Factor*
 4
 3
 
* Multiply the Running Active Power Rating {Watts} of the appliance by this Factor to arrive at
the Continuous Power Rating of the inverter for powering this appliance.
TABLE 2.1: NOTES


SECTION 2 | General Information
SECTION 3 | Limiting Electro-Magnetic
Interference (EMI)
These inverters contain internal switching devices that generate conducted and radiated



These limits are designed to provide reasonable protection against harmful interfer-
ence when the equipment is operated in a residential environment. These inverters can





iINFO
- Ensure that the inverter is rmly grounded to the ground system
of the building or the vehicle
 
audio and video devices as possible
 
as short as possible.
 
reduce their inductance and induced voltages. This reduces ripple in the bat-
tery wires and improves performance and efciency.
-Shield
-

 
equipment

SECTION 4 | Powering Direct / Embedded Switch
Mode Power Supplies (SMPS)





inrush current drawn by the power supply as the input capacitors are charged (The ca-

current at turn-on is several to tens of times larger than the rated RMS input current

waveforms is given in Fig. 4.1. It will be seen that the initial input current pulse just after




in Fig 4.2 above. The steady state input current of SMPS is a train of non-linear pulses
instead of a sinusoidal wave. These pulses are two to four milliseconds duration each

around 3 times the RMS value of the input current:


-

the input to the power supply. The cold resistance limits the input current as the input



current event.

Hence, it is recommended
that for purposes of sizing the inverter, the continuous power of the inverter should be
> 3 times the continuous rated power of the SMPS. For example, an SMPS rated at
100 Watts should be powered from an inverter that has continuous power of
> 300 Watts.

12 | SAMLEX AMERICA INC.
SECTION 4 | Powering Direct / Embedded Switch
Mode Power Supplies (SMPS)
Fig 4.1: Inrush current in an SMPS
Fig. 4.2: High Crest Factor of current drawn by SMPS
Input voltage
Inrush current RMS Current
TIME
Peak Current
RMS Current
Non-linear
Input Current
Input Sine
Wave Voltage

SECTION 5 | Principle of Operation



of grid power (Supplementary information on pure sine waveform and its advantages
are discussed on pages 8 & 9).

instantaneous value and polarity of the voltage varies cyclically with respect to time. For






Fig. 5.1: 120 VAC, 60 Hz Pure Sine Waveform





frequency and the pulse width of this switching is modulated with respect to a refer-
ence sine wave.
TIME
OV
+
-
-VPEAK = - 168.69V
+VPEAK = + 168.69V
VRMS = 120 VAC

14 | SAMLEX AMERICA INC.
SECTION 6 | Layout
2
3
LEGEND
1. NEMA5-20R GFCI Duplex Receptacle
2. Status LED - Power “ON” (GREEN)
Status LED - Abnormal (ORANGE)
3. ON/OFF Switch
4. Cooling Fan Opening
5. Grounding Terminal
6. Positive DC Input Terminal
7. Negative DC Input Terminal
PST-300: Front
PST
-300-12-24 Layout
PST-300: Back
WARNING: REVERSE POLARITY WILL
DAMAGE THE UNIT.
AVERTISSEMENT : INVERSION DE
POLARITÉ PEUT ENDOMMAGER L’UNITÉ.
1
4
5 76
Fig. 6.1: Layout of PST-300-12 and PST-300-24


1. 
2. 

powering of inverters.
Deep Cycle Lead Acid Batteries

-



powering these inverters.
Rated Capacity in Ampere-hour (Ah)
-



over a specied time in hours before the battery reaches a specied discharged terminal







Rated Capacity in Reserve Capacity (RC)


vehicle can be driven after the charging system fails. This is roughly equivalent to the
conditions after the alternator fails while the vehicle is being driven at night with the
headlights on. The battery alone must supply current to the headlights and the com-





Capacity “C” in Ah = Reserve Capacity in RC minutes x 0.6
SECTION 7 | General Information on Batteries for
Powering Inverters

16 | SAMLEX AMERICA INC.
SECTION 7 | General Information on Batteries for
Powering Inverters
Typical Battery Sizes
 
TABLE 7.1: POPULAR BATTERYSIZES
BCI* Group Battery Voltage, V Battery Capacity, Ah
 12 
 12 
 12 
 220

Specifying Charging / Discharging Currents: C-Rate

stored energy is related to the amount of the active materials pasted on the battery










EQUATION 1:
Discharge current “C-Rate” = Capacity “C” in Ah ÷ Discharge Time “T”

SECTION 7 | General Information on Batteries for
Powering Inverters

TABLE 7.2: DISCHARGE CURRENT RATES - “C-RATES”
Hours of discharge time “T”
till the “End Point Voltage”
C-Rate Discharge Current in Amps Example of C-Rate
Discharge Currents
for 100 Ah battery
Fraction Decimal Subscript
    
    
    

    

    

    
    
NOTE: -


.
Charging / Discharging Curves




(Please note that X-axis shows % State of Charge. State
of Discharge will be = 100% - % State of Charge). These curves will be referred to in

Reduction in Usable Capacity at Higher Discharge Rates –
Typical in Inverter Application
-




18 | SAMLEX AMERICA INC.
SECTION 7 | General Information on Batteries for
Powering Inverters
Fig. 7.1: Charging / Discharging Curves for 12V Lead Acid Battery
TABLE 7.3 BATTERYCAPACITY VERSUS RATE OF DISCHARGE – C-RATE
C-Rate Discharge Current 
 
 
 
 
 
 
 
 
12 Volt Lead-Acid Battery Chart - 80˚F
Battery Voltage in VDC
Battery State of Charge in Percent (%)
0 10 20 30 40 50 60 70 80 90 100 110 120 130
16.5
16.0
15.5
15.0
14.5
14.0
13.5
13.0
12.5
12.0
11.5
11.0
10.5
10.0
9.5
9.0
C/5
C/40
C/20
C/10
DISCHARGE
CHARGE
C/20
C/3
C/5
C/10
C/100
Please note that X-axis shows %
State of Charge. State of Discharge
will be = 100% - % State of Charge.



-





State of Charge (SOC) of a Battery – Based on “Standing Voltage”






multiply by 4.
TABLE 7.4: STATE OF CHARGE VERSUS STANDING VOLTAGE – 12V BATTERY
Percentage of
Full Charge
Standing Voltage of 6 Cell,
12V Nominal Battery
Standing Voltage
of Individual Cells
  
  
  
  
  
  
  
  
  
  
  


require equalization. Please note that only the non-sealed / vented / ooded / wet cell
batteries are equalized. Do not equalize sealed / VRLA type of AGM or Gel Cell Batteries.
State of Discharge of a loaded battery – Low Battery /
DC Input Voltage Alarm and Shutdown in Inverters
-

SECTION 7 | General Information on Batteries for
Powering Inverters

20 | SAMLEX AMERICA INC.
SECTION 7 | General Information on Batteries for
Powering Inverters


Inverters are provided with a buzzer alarm to warn that the loaded battery has been
Normally, the buzzer alarm is
triggered when the voltage at the DC input terminals of the inverter has dropped to
around 10.5V for a 12V battery or 21V for 24V battery at C-Rate discharge current of
C/5 Amps and electrolyte temp. of 80°F. The inverter is shut down if the terminal voltage


of the battery. The terminal voltage of the battery is dependent upon the following:
-Temperature of the battery electrolyte: Temperature of the electrolyte affects the


temperature and rises with drop in temperature
-The amount of discharging current or “C-Rate”:

decreases non-linearly
 -



Low DC Input Voltage Alarm in Inverters
-



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