DC-AC Inverters PSE-24125A PSE-24175A PSE-24275A Owner's Manual Please read this manual before operating your Inverter
INDEX INDEX Safety Instructions ............................................................................................. 2,3 Inverters - General Information ...................................................................... 4,5,6 Characteristics of Sinusoidal AC Power ............................................................... 7 AC Power Distribution and Grounding ........................................................ 8,9,10 Principle of Operation .............................................
SAFETY INSTRUCTIONS Please read these instructions before installing or operating the inverter to prevent personal injury or damage to the inverter.
INVERTER RELATED Preventing paralleling of the AC output The AC output of this inverter cannot be synchronised with another AC source and hence, it is not suitable for paralleling. The AC output of the inverter should never be connected directly to an electrical breaker panel / load center which is also fed from the utility power / generator.
INVERTERS - GENERAL INFORMATION Why an inverter is needed The utility grid supplies you with alternating current (AC) electricity. AC is the standard form of electricity for anything that “plugs in” to the utility power. Direct current (DC) electricity flows in a single direction. Batteries provide DC electricity. AC alternates its direction many times per second. AC is used for grid service because it is more practical for long distance transmission.
Loads that require “surge power” to start Resistive types of loads (like incandescent lamps, toaster, coffee maker, electric range, iron etc) do not require extra power to start. Their starting power is the same as their running power. Some loads like induction motors and high inertia motor driven devices will initially require a very large starting or “surge” power to start from rest.
Power rating of Microwaves The power rating of the microwave generally refers to the cooking power. The electrical power consumed by the microwave will be approximately 2 times the cooking power. The “surge power” of the inverter should be 2 times the electrical power (i.e., 4 times the cooking power).
CHARACTERISTICS OF SINUSOIDAL AC POWER Voltage, current, power factor, types of loads The voltage waveform of 120 VAC, 60 Hz mains / utility power is like a sine wave. In a voltage with a sine wave-form, the instantaneous value and polarity of the voltage varies with respect to time and the wave-form is like a sine wave.
AC POWER DISTRIBUTION AND GROUNDING CAUTION! PLEASE NOTE THAT THE AC OUTPUT CONNECTIONS AND THE DC INPUT CONNECTIONS ON THESE INVERTERS ARE NOT CONNECTED (BONDED) TO THE METAL CHASSIS OF THE INVERTER. BOTH THE INPUT AND OUTPUT CONNECTIONS ARE ISOLATED FROM THE METAL CHASSIS AND FROM EACH OTHER. SYSTEM GROUNDING, AS REQUIRED BY NATIONAL / LOCAL ELECTRICAL CODES / STANDARDS, IS THE RESPONSIBILITY OF THE USER / SYSTEM INSTALLER.
Grounded Electrical Power Distribution System The National Electrical Code (NEC) requires the use of a “grounded electrical distribution system”. As per this system, one of the two current-carrying conductors is required to be grounded. This grounded conductor is called the “Neutral / Cold / Return”. As this conductor is bonded to earth ground, it will be at near zero voltage or potential. There is no risk of electrical shock if this conductor is touched.
PSE-24275A is also provided with a separate plate which has a NEMA 5-15R receptacle wired through a 15 A beaker. This plate with the receptacle and breaker fits in the pocket through which the output conductors exit the inverter. The NEMA 5-15R receptacle can be connected to the three output conductors if the AC power output is required to be drawn from the front panel of the inverter.
PRINCIPLE OF OPERATION The inverter converts the 24 V (nominal) DC voltage of the battery to 120 V, 60 Hz. AC voltage. The voltage conversion takes place in two stages. In the first stage, the 24 V (nominal) DC voltage of the battery is converted to high voltage DC (155 V to 170 V) using high frequency switching and Pulse Width Modulation (PWM) technique. In the second stage, the high voltage DC is converted to 120 V, 60 Hz. modified sine-wave AC (Note: 120 V is the RMS value of the AC voltage.
DEVICES THAT MAY NOT OPERATE ON MODIFIED SINE WAVE The output wave form of these inverters is a modified sine wave. See the diagram under “Principle of Operation” on page 11. In a sine wave, the voltage rises and falls smoothly with a smoothly changing phase angle and also changes its polarity instantly when it crosses 0 Volts. In a modified sine wave, the voltage rises and falls abruptly, the phase angle also changes abruptly and it sits at 0 Volts for some time before changing its polarity.
LIMITING ELECTRO-MAGNETIC INTERFERENCE (EMI) The inverter contains internal switching devices which generate conducted and radiated electromagnetic interference (EMI). The EMI is more pronounced in inverters whose output voltage has modified sine wave form as modified sine wave form is composed of odd harmonics of the fundamental frequency. These harmonics may produce buzzing sound in inexpensive stereo systems because the power supply of these systems does not provide adequate filtration.
LAYOUT PSE-24125A, PSE-24175A b. a. c. d. e. f. Rear View h. i. g. Bottom View PSE-24275A b. e. a. k. c. d. j. f. Front View h. g. i.
FEATURES, CONTROLS & INDICATIONS Important : Each of the following operating procedures and safety features must be carefully reviewed and thoroughly understood prior to using the inverter. Failure to do so may result in damage to the inverter or equipment or serious personal injury a ON/OFF Switch. This switch operates a low power control circuitry which in turn controls the high power circuitry. b High Temperature LED Indicator Light.
Battery Current & Voltage Bar Graph Meters (GREEN, YELLOW, RED). d Current Indicator. This illuminated Bar Graph monitors the current being drawn from the battery by the inverter. Depending on the amount of current being drawn, the Bar Graph reading generally will be in the GREEN or YELLOW zone. When the reading rises to the RED zone, the inverter may automatically shut down. e Two Standard North American NEMA 5-15R Receptacles are provided on models PSE-24125A and PSE-24175A.
SPECIFYING BATTERIES, CHARGERS & ALTERNATORS The inverter will require Deep Cycle Lead Acid Batteries of appropriate capacity. Lead-acid batteries can be categorized by the type of application: automotive service Starting/Lighting/Ignition (SLI, a.k.a. cranking) and deep cycle service SLI Batteries Everybody is familiar with the SLI batteries that are used for automotive starting and powering vehicular accessories.
Typical battery sizes Below is a chart of some battery sizes applicable for powering inverters: BCI * Group 27 / 31 4D 8D GC2** Battery Voltage, V 12 12 12 6 Battery AH 105 160 225 220 * Battery Council International ** Golf Cart Reduction in usable capacity at higher discharge rates. As stated above, the rated capacity of the battery in AH is applicable at a discharge rate of 20 Hours. As the discharge rate is increased, the usable capacity reduces due to “Peukert Effect”.
Depth of discharge and battery life The more deeply a battery is discharged on each cycle, the shorter the battery life. Using more batteries than the minimum required will result in longer life for the battery bank. A typical cycle life chart is given at Table 2 below: TABLE 2.
Sizing the Inverter Battery Bank One of the most frequently asked question is, “how long will the batteries last?’. This question cannot be answered without knowing the size of the battery system and the load on the inverter. Usually this question is turned around to ask “How long do you want your load to run?”, and then specific calculation can be done to determine the proper battery bank size.
Charging Batteries The batteries can be charged by using good quality AC powered battery charger or from alternative energy sources like solar panels, wind or hydro systems. Make sure an appropriate battery charge controller is used. It is recommended that the batteries may be charged at 10% to 13 % of the Ampere Hour capacity (20 hour discharge rate).
INSTALLATION The success of a DC to AC power inverter installation depends mainly on the methods and materials used for installation.
Cooling by forced air fan ventilation The inverters produce heat when operating. The amount of heat produced is proportional to the amount of power supplied by the inverter. DC fans are used to provide forced air cooling of these inverters. The fans are thermostatically controlled and will be switched on only if the temperature of certain hot spot inside the inverter rises above a certain temperature. At lower loads and / or at lower ambient temperatures, the fan may not switch on at all. This is normal.
Preventing reverse polarity on the input side When making battery connection on the input side, make sure that the polarity of battery connection is correct (Connect the positive of the battery to the positive terminal of the inverter and the negative of the battery to the negative terminal of the inverter).
Using proper DC cable termination The battery end and the inverter end of the cables should have proper terminals that will ensure a firm and tight connection. DC input terminals on PSE-24125A and PSE-24175A The DC input terminals on PSE-24125A and PSE-24175A have a tubular hole with a set screw. A suitable pin type of copper terminal should, therefore, be used on the cable end. (A pair of pin type terminals has been provided.
Connecting to multi-wire branch circuits Do not directly connect the hot side of the 120 VAC of the inverter model to the two hot legs of the 120 / 240 VAC electrical breaker panel / load centre where multi-wire ( common neutral ) branch circuit wiring method is used for distribution of AC power. This may lead to overloading / overheating of the neutral conductor and is a risk of fire.
Grounding of PSE-24125A / PSE-24275A to earth or to other designated ground Please see details regarding grounding under “AC Power Distribution and Grounding” on page 8 For safety, the metal chassis of the inverter is required to be grounded to the earth ground or to the other designated ground (For example, in a mobile RV, the metal frame of the RV is normally designated as the negative DC ground).
OPERATION Powering on the loads After the inverter is switched on, it takes a finite time for it to become ready to deliver full power. Hence, always switch on the load(s) after a few seconds of switching on the inverter. Avoid switching on the inverter with the load already switched on. This may prematurely trigger the overload protection. When a load is switched on, it may require initial higher power surge to start.
Switching on / off using the optional remote on / off Remote Control An optional corded Remote Control, Model No. RC-15, is available to enable switching on and off from a distance of 18 ft. The remote on / off control comes with 18 ft. of wire. One end of the remote control is plugged into the 6 position modular jack (f) provided on the inverter. To use the remote control, the inverter is first required to be switched on from the on / off switch on the front panel.
Shut-down due to reversal of polarity at the DC input terminals. The positive of the battery should be connected to the positive DC input terminal of the inverter and the negative of the battery should be connected to the negative DC input terminal of the inverter.
TROUBLESHOOTING GUIDE SYMPTOM On switching on, the input voltage bar graph indicator does not light. There is no AC voltage POSSIBLE CAUSE REMEDY There is no voltage at the DC input terminals 1. Check the continuity of the battery input circuit. 2. Check that the battery fuse is intact. Replace if blown 3.
SYMPTOM POSSIBLE CAUSE REMEDY The AC output shuts down sometimes and resumes automatically. Overload LED is not lighted ( might happen during starting of certain loads) Temporary shut-down of the AC output due to instantaneous overload beyond the surge power rating of the inverter 1. Reduce the load 2. The load is not suitable as it requires higher power to operate. Use an inverter with higher power rating The AC output shuts down completely. The red overload LED is lighted.
SPECIFICATIONS PSE-24125A 20-33 V 120 V +5% / -10% 60Hz +/- 5% 1250 W* 2500 W 320 mA Modified Sine Wave 85 to 90% Input Voltage, Volts DC Output voltage, Volts RMS Output frequency, Hz Continuous output power, Watts Instantaneous overload (surge< 2 seconds) No load current draw Output Waveform Peak efficiency PSE-24175A 20-33V 120 V + 5% / -10% 60Hz +/- 5% 1750 W* 3500 W 370 mA Modified Sine Wave 85 to 90% PSE-24275A 20-33 V 120 V + 5% / -10% 60Hz +/- 5% 2750 W* 4500 W 600 mA Modified Sine Wave 85 to 90%
2 YEAR Limited Warranty PSE-24125A, PSE-24175A & PSE-24275A's manufactured by Samlex America, Inc. (the “Warrantor”) are warranted to be free from defects in workmanship and materials under normal use and service. This warranty is in effect for 2 years from the date of purchase by the user (the “Purchaser”) For a warranty claim, the Purchaser should contact the place of purchase to obtain a Return Authorization Number.
110-17 Fawcett Rd T: 604 525 3836 Coquitlam, B.C. F: 604 525 5221 Canada V3K 6V2 Version PSE-24125/24175/24275 (Apr.2005) e-mail: samlex@samlexamerica.com website: www.samlexamerica.
