Trace Engineering DR Series, DR1512, DR2412, DR1524, DR2424 Owner's Manual
...
Owner’s Manual
DR SERIES
INVERTER/CHARGERS
V 3.2
Effective 9/7/98
PN: 830-5 Rev 3.2
Trace Engineering Company, Inc.
5916 195th Street N.E.
Arlington, WA 98223
Tel (360) 435-8826
Fax (360) 435-2229
Packaging Materials
Thank you for choosing Trace Engineering products to meet your alternative-energy power needs. We
make every effort to ensure that your inverter/charger packaging includes the following materials:
Owner’s Manual;
Red, Black, & Green battery terminal covers (with hardware);
Hardware package for hardware covers;
Quick Setup Sheet
Hardwire Box with Hardware (2.4KW and larger inverters only)
Declaration of Conformity (Export models only)
Trace bumper sticker;
If any of the above listed materials are missing from your package, or if it is unsatisfactory in any
manner, please call Customer Service at (360) 435-8826 or fax this page with your comments to (360)
435-2229.
Model Number: _____________________________________
Serial Number: _____________________________________
Purchase Date: _____________________________________
Comments: _____________________________________________________________________
______________________________________________________________________________
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Thank you for choosing Trace Engineering to meet your independent power needs. Check out our
web site at www.traceengineering.com for more information and answers to your FAQ’s.
Table of Contents
IMPORTANT SAFETY INSTRUCTIONS ..............................................................1
Theory of Inverter Operation..............................................................................3
Inverter Operation ...............................................................................................4
Front Panel Controls and LED Indicators................................................................................ 4
Power On/Off .............................................................................................................................. 4
Inverter Mode LED...................................................................................................................... 4
Search Mode Watts .................................................................................................................... 5
Over Discharge Protection and AC Transfer Voltage............................................................. 6
AC Transfer Voltage................................................................................................................... 7
Battery Bank Capacity ............................................................................................................... 7
Protection Circuitry.................................................................................................................... 8
Battery Charger ...................................................................................................9
Charger Terminology................................................................................................................. 9
Three Stage Battery Charging................................................................................................. 10
Battery Charger Controls and LED Indicator..................................................11
Battery Type Selector........................................................................................12
Battery Charger Settings..................................................................................13
Generator Requirements......................................................................................................... 14
Peak Voltage Available vs. Charge Rate Amps..................................................................... 14
Batteries.............................................................................................................15
Battery Terminology ................................................................................................................ 15
Selection of Battery Type........................................................................................................ 15
Battery Sizing............................................................................................................................ 17
Battery Care and Maintenance................................................................................................ 18
Monthly Maintenance............................................................................................................... 18
Battery Hook-up Configurations............................................................................................. 19
Battery Installation................................................................................................................... 20
INSTALLA TION..............................................................................................22
Environment ............................................................................................................................. 22
AC Wiring...........................................................................................................24
AC Connections........................................................................................................................ 24
Minimum Recommended Wire Sizes...................................................................................... 25
Ground Fault Interrupting Outlets (GFI’s).............................................................................. 25
DC Wiring...........................................................................................................26
DC Disconnect.......................................................................................................................... 26
DC Fusing ................................................................................................................................. 26
Battery Cable Connection ....................................................................................................... 27
Battery Cable Sizing................................................................................................................. 27
System Safety Wiring Requirements...............................................................28
Stacking Inverters.............................................................................................29
Connections.............................................................................................................................. 29
Operation .................................................................................................................................. 30
Theory of Operation................................................................................................................. 30
Search Mode Operation with Stacked Pairs.......................................................................... 30
RC4 Remote Control .........................................................................................31
Installation Diagrams........................................................................................32
A. Installation with Single AC Panel....................................................................................... 32
B. Installation with AC Sub Panel........................................................................................... 33
C. Installation with External Relay......................................................................................... 34
Troubleshooting Guide..................................................................................... 35
Applications....................................................................................................... 37
Technical Information....................................................................................... 40
Performance Graphs......................................................................................... 41
Typical Battery Draw of Common Appliances................................................ 44
Other Products available from Trace Engineering......................................... 48
Limited Warranty............................................................................................... 49
Life Support Policy............................................................................................49
Table of Figures
FIGURE 1 , COMPARISON OF AC WAVEFORMS........................................................................ 3
FIGURE 2, CONTROL PANEL........................................................................................................ 4
FIGURE 3, ODP CONTROL............................................................................................................ 6
FIGURE 4, RECOMMENDED DISCHARGE CUTOFF VOLTAGE PER CELL.............................. 6
FIGURE 5, DR SERIES AC HARDWIRING .................................................................................. 24
FIGURE 6, INSTALLATION WITH A SINGLE AC PANEL............................................................ 32
FIGURE 7, INSTALLATION WITH AN AC SUB PANEL ............................................................... 33
FIGURE 8, INSTALLATION WITH EXTERNAL RELAY................................................................ 34
FIGURE 9, LOAD CAPACITY VS. TIME ....................................................................................... 41
FIGURE 10, POWER OUTPUT VS. EFFICIENCY........................................................................ 42
FIGURE 11, MAXIMUM REGULATED POWER OUTPUT VS. BATTERY VOLTAGE................. 43
FIGURE 12, DIMENSIONED DR SERIES INSTALLATION DRAWING ....................................... 47
Tables
TABLE 1, AC TRANSFER VOLTAGE ............................................................................................. 7
TABLE 2, BULK, FLOAT, AND EQUALIZE VOLTAGES FOR DR SERIES INVERTERS............ 12
TABLE 3, PEAK VOLTAGE VS. CHARGE RATE AMPS.............................................................. 14
TABLE 4, MAXIMUM CHARGE RATE WITH SOME TYPICAL GENERATOR MODELS............ 14
TABLE 5, MINIMUM RECOMMENDED WIRE SIZES................................................................... 25
TABLE 6, FUSE OR BREAKER SIZE REQUIRED VS. CABLE SIZE........................................... 26
TABLE 7, MINIMUM RECOMMENDED BATTERY CABLE SIZE (IN FREE AIR) ........................ 27
TABLE 8, TYPICAL BATTERY DRAW OF COMMON APPLIANCES (12V)................................. 44
TABLE 9, TYPICAL BATTERY DRAW OF COMMON APPLIANCES (24V)................................. 45
TABLE 10, ENGLISH TO METRIC WIRE CONVERSION TABLE................................................ 46
TABLE 11, SAFETY GROUND WIRE SIZE TABLE...................................................................... 46
Trace Engineering DR Series Owner’s Manual - Version 3.2 - 9/7/98 - Page 1
IMPORTANT SAFETY INSTRUCTIONS
SAVE THESE INSTRUCTIONS !!
This manual contains important safety and operating instructions as prescribed by UL specifications
for inverters used in residential applications. This manual covers all DR series inverter/charger models.
The entire DR Series of inverters is ETL listed to the UL standard 1741 (Draft), Power conditioning
units for use in residential photovoltaic power systems. The DR series is also ETL listed to Canadian
standard CSA - C 22.2 No. 107.1 - M1, Commercial and Industrial Power Supplies.
General Precautions
1. Before using the inverter/charger, read all instructions and cautionary markings on (1) the
inverter/charger, (2) the batteries and (3) all appropriate sections of this instruction manual.
2. CAUTION - To reduce risk of injury, charge only deep-cycle lead acid, lead antimony, lead
calcium, gel cell, absorbed mat, or NiCad/NiFe type rechargeable batteries. Other types of
batteries may burst, causing personal injury and damage.
3. Do not expose inverter/charger to rain, snow or liquids of any type. The inverter is designed
for indoor mounting only. Protect the inverter from splashing if used in vehicle applications.
4. Do not disassemble the inverter/charger; take it to a qualified service center when service or
repair is required. Incorrect re-assembly may result in a risk of electric shock or fire.
5. To reduce risk of electric shock, disconnect all wiring before attempting any maintenance or
cleaning. Turning off the inverter will not reduce this risk. Solar modules produce power when
exposed to light - cover them with opaque material before servicing any connected
equipment.
6. WARNING - WORKING IN VICINITY OF A LEAD ACID BATTERY IS DANGEROUS.
BATTERIES GENERATE EXPLOSIVE GASES DURING NORMAL OPERATION. Provide
ventilation to outdoors from the battery compartment. The battery enclosure should be
designed to prevent accumulation and concentration of hydrogen gas in “pockets” at the top
of the compartment. Vent the battery compartment from the highest point. A sloped lid can
also be used to direct the flow to the vent opening location.
7. NEVER charge a frozen battery.
8. No terminals or lugs are required for hook-up of the AC wiring. AC wiring must be no less than
10 AWG (5.3 mm
rated for 75°C or higher and should be no less than 2/0 AWG (67.4 mm
and sealed copper ring terminal lugs with a 5/16 hole should be used to connect the battery
cables to the DC terminals of the inverter/charger. Soldered cable lugs are also acceptable.
See section on battery cable sizing for correct battery cable size and length for your
application.
9. Torque all AC wiring connections to 15-20 inch-pounds. Torque all DC cable connections to
10-12 foot- pounds. Be extra cautious when working with metal tools on, or around batteries.
The potential exists to drop a tool and short-circuit the batteries or other electrical parts
resulting in sparks that could cause an explosion.
2
) gauge copper wire and rated for 75°C or higher. Battery cables must be
2
) gauge. Crimped
Trace Engineering DR Series Owner’s Manual - Version 3.2 - 9/7/98 - Page 2
Tools required to make AC wiring connections: Wire strippers, ½” (13MM) open-end wrench or
socket, Phillips screw driver #2, Slotted screw driver ¼” (6MM) blade.
10. This inverter/charger is intended to be used with a battery supply of nominal voltage that
matches the last two digits of the model number, e.g. 12 volts with a DR1512 or 24 volts with
a DR1524.
11. Instructions for wall mounting: See mounting instruction section of this manual. NOTE: Do not
use only the keyhole mounting slots for permanent installations. For battery installation and
maintenance: read the battery manufacturer’s installation and maintenance instructions prior
to operating.
12. No AC or DC disconnects are provided as an integral part of this inverter. Both AC and DC
disconnects must be provided as part of the system installation. See INSTALLATION section
of this manual.
13. No overcurrent protection for the battery supply is provided as an integral part of this inverter.
Overcurrent protection of the battery cables must be provided as part of the system
installation. See INSTALLATION section of this manual.
14. No overcurrent protection for the AC output wiring is provided as an integral part of this
inverter. Overcurrent protection of the AC output wiring must be provided as part of the
system installation. See INSTALLATION section of this manual.
15. GROUNDING INSTRUCTIONS - This battery charger should be connected to a grounded,
permanent wiring system. For most installations, the negative battery conductor should be
bonded to the grounding system at one (and only one point) in the system. All installations
should comply with all national and local codes and ordinances.
Personal Precautions
1. Someone should be within range of your voice to come to your aid when you work near
batteries.
2. Have plenty of fresh water and soap nearby in case battery acid contacts skin, clothing, or
eyes.
3. Wear complete eye protection and clothing protection. Avoid touching eyes while working
near batteries. Wash your hands when done.
4. If battery acid contacts skin or clothing, wash immediately with soap and water. If acid enters
eyes, immediately flood eyes with running cool water for at least 15 minutes and get medical
attention immediately.
5. Baking soda neutralizes lead acid battery electrolyte. Vinegar neutralizes spilled NiCad and
NiFe battery electrolyte. Keep a supply on hand in the area of the batteries.
6. NEVER smoke or allow a spark or flame in vicinity of a battery or generator.
7. Be extra cautious when working with metal tools on, and around batteries. Potential exists to
short-circuit the batteries or other electrical parts which may result in a spark which could
cause an explosion.
8. Remove personal metal items such as rings, bracelets, necklaces, and watches when
working with a battery. A battery can produce a short-circuit current high enough to weld a
ring, or the like, to metal causing severe burns.
9. If a remote or automatic generator start system is used, disable the automatic starting circuit
and/or disconnect the generator from its starting battery while servicing to prevent accidental
starting during servicing.
Trace Engineering DR Series Owner’s Manual - Version 3.2 - 9/7/98 - Page 3
Theory of Inverter Operation
Waveform
The output waveform of the inverter is referred to as a modified sine wave. This waveform is suitable
for a wide variety of applications. Induction motors (i.e. refrigerators, drill presses), resistive loads (i.e.
heaters, toasters), universal motors (i.e. hand tools, vacuum cleaners) as well as microwave ovens
and computers are all suitable loads.
Figure 1 , Comparison of AC Waveforms
The waveform could be more accurately described as a pulse width modified square wave. The
accompanying Figure 1 shows the relationships between square wave, sine wave and modified sine
wave formats.
Regulation
The inverter is RMS voltage regulated. RMS regulation ensures that loads will always have the
same amount of power delivered to them as battery voltage changes. Regulation is achieved by
varying the width of each output pulse in the waveform. Peak voltage is the product of the battery
voltage times the turns ratio of the inverter’s power transformer and is therefore not regulated.
Trace Engineering DR Series Owner’s Manual - Version 3.2 - 9/7/98 - Page 4
Inverter Operation
Front Panel Controls and LED Indicators
Shown below are the controls and indicator lights on the front of the DR series inverter/charger. These
control and provide information when in either inverter or battery charging mode of operation. All
models of the DR series operate identically.
Figure 2, Control Panel
Power On/Off
Located on the left of the panel is the momentary POWER ON/OFF button. Once the inverter has been
properly installed and the batteries are connected, pressing this button momentarily will alternately turn
the inverter on and off. Each time it is pressed the inverter will sound an audible chirp. Note: When
first connected to batteries, the inverter will run through a self-test, and go to an off state. It may then
be activated by pressing the on/off button. Note: The self-test consists of the control panel lights
lighting up in sequence, the internal cooling fan will run momentarily, and the transfer relay will click
three times.
Inverter Mode LED
This green LED indicator lights when the unit is in the inverter mode (not charging batteries) delivering
full output voltage. When the inverter is in its search mode the green LED will blink about 2-3 times per
second.
Trace Engineering DR Series Owner’s Manual - Version 3.2 - 9/7/98 - Page 5
Search Mode Watts
The SEARCH MODE WATTS control is used for adjusting the sensitivity of the search mode circuit.
The DR Series inverters feature a circuit that minimizes power drain by reducing the inverter’s output
to small test pulses when there is no load connected to the inverter. These pulses are used to detect
the presence of a load. When a load is detected the inverter’s output goes to full voltage. The
sensitivity of the detection threshold is adjustable. Turning the SEARCH MODE WATTS control
clockwise decreases the sensitivity. Turning the control full counterclockwise increases sensitivity and
at the full counterclockwise position, defeats the search mode feature.
Example: With the SEARCH MODE WATTS control set to detect a 40 watt load, a 50 watt load will
bring the unit to full output voltage. However, a 30 watt load will leave the inverter in its energy saving
search mode state. If the sensitivity is increased by setting the control to 10, a 20 watt load will bring
the inverter out of the search mode, while a 5 watt load will not.
When in the search mode, the green power LED will blink and the inverter will make a ticking sound.
At full output voltage, the green power LED will remain lit and the inverter will make a steady buzzing
sound. When the inverter is used as an uninterruptable power supply, the search mode function
should be defeated by turning the control completely to the left (counter clockwise).
A neon type nightlite can also be used as a good indicator to determine if the inverter is in search
mode. Simply plug the light into any AC outlet that is connected to the inverter’s output. When the
inverter is in the search mode the light will blink. If the inverter is running a load, the light will be on
continuously.
Exceptions: (Murphy’s Law) Unfortunately, things don’t always work the way the manual says they
will.
Example A: If the SEARCH MODE WATTS control is set to detect a 40 watt load and a 30 watt
incandescent light is turned on, the inverter will detect the light. The light is a bigger load than 40 watts
when its filaments are cold. When the light gets hot it becomes a 30 watt load. Since this is below the
control setting of 40, the inverter will not detect it and the light will go out. This will cause the light to
cycle repeatedly.
Example B: If the SEARCH MODE WATTS control is set to detect a 30 watt load and a 40 watt
fluorescent light is turned on, the inverter will not detect the light. The light presents a smaller load than
30 watts until the gas in the fluorescent tube ionizes.
Example C: There are some appliances that draw power even though they are turned off. TVs with
instant on circuits, microwave ovens with digital displays and VCRs are examples. These loads
present a dilemma. If the sensitivity is set higher than the combination of these loads, then an auxiliary
load must be used to bring the inverter out of the search mode before the appliances can be turned
on. If the sensitivity is set lower than this combination of loads, the loads will be left on and will put an
additional drain on the batteries. (Three such 15 watt loads would amount to an additional 90
amp/hours per 24 hours in a 12 VDC system.)
One solution is to turn these items off at the wall. Use an extension cord with a rocker switch, a switch
at the outlet, or the appropriate circuit breaker. Another solution might be to place all these phantom
loads on a separate circuit with its own disconnect.
Trace Engineering DR Series Owner’s Manual - Version 3.2 - 9/7/98 - Page 6
Over Discharge Protection and AC Transfer Voltage
This control enables or disables the over discharge protection system (ODP) and allows adjustment of
the AC transfer voltage. With the dial set to either the left or right side of the scale, transfer voltage can
be adjusted from minimum to maximum. The voltage will vary depending on the model of inverter you
have. See the chart on the next page for transfer voltage values.
ODP (AC Transfer Voltage) Control
Located on the right of the control panel is the OVER-DISCHARGE
PROTECTION control. This circuit is unique to Trace Inverters. Its
purpose is to protect the batteries from being over-discharged. This
circuit monitors both the current being drawn by the inverter and the
battery voltage. Battery voltage alone is not an accurate indicator of
battery condition. The internal resistance of a battery causes its
output voltage to drop when the battery is delivering current. The
smaller the battery, the greater the voltage drop for a given load. This
battery voltage drop due to load is not an indicator of the battery’s
state of charge. The Trace “load compensated” circuit uses
information about the battery bank size, temperature and the load
current to derive a corrected battery voltage. Below is a chart showing
the maximum discharge voltage per cell for different load currents and
battery sizes. For example: A battery bank with a 1000 amp-hour capacity being discharged by a load
requiring 100 amps/hour has a factor of 0.1 (100/1000). Enter the chart from the bottom at 0.1,
proceed up to the curve and then to the left. This shows that a minimum voltage of 1.73 volts per cell
should be observed. This chart is useful when customizing the DR inverter to different size systems.
Figure 3, ODP Control
2
1.95
C
1.9
e
1.85
l
l
1.8
V
1.75
o
1.7
l
t
1.65
12VDC
12.0
11.4
10.8
24VDC
24.0
22.8
21.6
a
1.6
g
e
1.55
1.5
1 0.1 0.01 0.001
Discharge Rate/ Battery Capacity
10.2
9.6
9.0
20.4
19.2
18.0
Figure 4, Recommended Discharge Cutoff Voltage per Cell
The over discharge protection control is turned clockwise to activate the circuit. It is defeated by
turning the control fully counterclockwise. If the over discharge circuit is defeated, the inverter itself is
protected from low battery voltage conditions by an additional low battery protection circuit which has a
threshold of 8.2 volts DC.
Trace Engineering DR Series Owner’s Manual - Version 3.2 - 9/7/98 - Page 7
AC Transfer Voltage
When the AC source (either public power or a generator) fails or falls to a low level (browns out), the
unit changes from battery charger mode to inverter mode. The AC voltage point at which the inverter
decides to change modes is called the AC transfer voltage. It is adjustable from minimum to maximum.
The adjustment is made by rotating the ODP knob between the 9:00 and 1:00 o’clock position if you
want the ODP defeated, or by rotating the knob between 2:00 and 5:00 o’clock if you want the ODP
enabled. As the knob is turned clockwise the transfer voltage increases if the ODP is defeated, or
decreases if the ODP is enabled. It is best to set the transfer voltage by first rotating the control all the
way to the left (off position), then to the desired position. See Figure 3.
Below is a chart showing the AC transfer voltages depending on the particular AC input/output voltage
of the unit. Note that adjusting the dial to a higher voltage setting results in slightly faster transfer
times, since it will take less of a voltage drop to trigger the transfer. Lower settings are less likely to
cause a transfer due to voltage fluctuations.
ODP ADJUSTMENT AC TRANSFER VOLTAGE
ODP
OFF
9:00 (MIN) 5:00 36 VAC 40 VAC 80 VAC
1:00 (MAX) 2:00 95 VAC 105 VAC 210 VAC
ODP
ON
100 - 105 VAC UNITS
(J OR K)
77 VAC 85 VAC 170 VAC
81 VAC 90 VAC 180 VAC
86 VAC 95 VAC 190 VAC
90 VAC 100 VAC 200 VAC
120 VAC UNITS (USA) 220 - 240 VAC UNITS
(W OR E)
Table 1, AC Transfer Voltage
Battery Bank Capacity
The BATTERY CAPACITY control is used to inform the inverter’s microprocessor about the size of the
battery bank being used. The microprocessor uses the formula of “battery capacity/40” to determine
what current level the bulk/absorption charge terminates (a maximum time of 12 hours is allotted for
bulk/absorption charge) and the float charge stage begins. This allows the inverter to make better
“Over-Discharge Protection” and battery charging decisions. Battery bank size is adjustable from 50 to
1000 (1K) amp-hours. Set this adjustment to the setting closest to the size of your battery bank (in
amp-hours).
Note: .37K = 370 amp-hours, .5K = 500 amp-hours, an 1K = 1000 amp-hours. If your battery bank is
1000 amp-hours or greater, adjust the BATTERY CAPACITY control to the 1K position.
Trace Engineering DR Series Owner’s Manual - Version 3.2 - 9/7/98 - Page 8
Protection Circuitry
The inverter will automatically restart itself from the following overload conditions: low battery, high
battery, shorted output, over current, and over temperature.
The inverter will turn itself off and require a manual restart if it encounters an overload for
approximately 10 seconds (a prolonged short circuit), or if AC output is directly connected to an AC
power source (public power or generator).
Two LED’s are provided to report on error conditions:
BATTERY HI RED/ BATTERY LOW GRN - This LED lights red when battery voltage is too high for
safe operation, and is green when voltage is too low for safe operation. When the voltage returns to a
safe level, the inverter restarts automatically.
In alternative energy applications (solar, wind, hydro) all DC charge controllers must be set to a
Note:
level below the inverter’s MAXIMUM INPUT VOLTAGE or the inverter may shut off unexpectedly. The
maximum input voltage for DR series inverters is, 15.5 volts DC for 12 volt inverters, and 31.0 volts DC
for 24 volt models.
Note: The battery charger control circuit operates from battery voltage. If battery voltage falls below 7
volts, neither the charger nor the inverter will operate. In this situation, a small charge from a standalone charger will be required to bring the battery to a high enough voltage for the inverter/charger to
resume operation.
OVERTEMP RED / OVERLOAD GRN- This LED lights red when the inverter’s temperature is too high
for safe operation and is green if the load is too large for the inverter to safely operate. When the
temperature returns to a safe level, the inverter restarts. The inverter will restart automatically if the
overload condition lasts for less than 10 seconds.
If the green overload LED is on when the unit is in the charger or search modes then there is a charger
fault. This means that the charger is charging even though the regulation system is trying to turn it off.
The unit will turn this LED on when a fault is detected, and will continue for up to one hour if the
condition persists. After this period the charger will shut down, disconnect the relay and continue to
display the green overload LED. The unit may be reset manually by pressing the power on/off switch,
and will continue to operate for another one hour period if the condition has not been corrected. The
inverter portion will continue to work normally throughout this type of fault. Contact your Trace
Engineering service center for repair if this type of fault is encountered.
The green overload LED will also come on in the event of a “backfeed” condition. This condition
could occur if AC power is applied to the inverter’s output. The LED will light from 1-10 seconds
when the condition is detected, after which the inverter will shut down. To correct this condition
remove the AC input power from the inverter’s output. The unit must then be reset by pressing the
power on/off switch.
Caution: Repeated connection of an AC source directly to the AC output may cause
damage to the inverter.
Trace Engineering DR Series Owner’s Manual - Version 3.2 - 9/7/98 - Page 9
Battery Charger
Theory of Operation
Inverter to Charger Transition
The internal battery charger and automatic transfer relay allows the unit to operate as either a battery
charger or inverter (but not both at the same time). An external source of AC power (e.g., shore power
or generator) must be supplied to the inverter’s AC input in order to allow it to operate as a battery
charger. When the unit is operating as a charger, AC loads are powered by the external source (i.e.
generator or public power).
The inverter automatically becomes a battery charger whenever AC power is supplied to its AC inputs.
There is a 40 second time delay from the time the inverter senses that AC is present at its input and
when the transfer is made. This delay is built in to provide time for a generator to spin-up to a stable
voltage and avoid relay chattering. The inverter’s AC input is internally connected to the inverter’s AC
output while in the battery charger mode. The maximum power that can be handled by the inverter’s
internal wiring and transfer relay is 30 amps (20 amps for export models).
Transfer Switching Speed
While this inverter is not designed specifically to operate as an uninterruptable power supply (UPS)
system, its transfer time is normally fast enough to hold up computers. The transfer time is a maximum
of 32 milliseconds. Success as a UPS will vary with computer models, and cannot be guaranteed.
Charger Terminology
•
Bulk Voltage- This is the maximum voltage at which the batteries will be charged during a
normal charging cycle. The normal range is 2.367 to 2.4 volts per cell. For a 12 VDC battery
(6 cells) this is 14.2 to 14.4. Liquid electrolyte batteries are usually set to the higher voltage,
while gel cell batteries are set to the lower voltage. (See page 18, Battery Care and
Maintenance, ”Bulk Voltage”).
•
Absorption - During this part of the charge cycle, the batteries are held at the bulk voltage
and accept whatever current is required to maintain this voltage. This ensures full charging.
• Float Voltage - This is the voltage at which the batteries will be maintained after they have been
charged. A range of 13.2 -13.4 for 12 volt systems is appropriate for most sealed and non-sealed
batteries. 13.2 volts is appropriate for gel cell batteries, and 13.4 volts is common for liquid lead
acid types. Check with the specific battery manufacturer for actual float voltage figures.
•
Equalize - The batteries are held above 15.0 Volts DC for a period to “boil” or mix the cells thus
reducing stratification and lead sulfate build-ups. This is not necessary or safe with sealed
batteries.
Trace Engineering DR Series Owner’s Manual - Version 3.2 - 9/7/98 - Page 10
d
Three Stage Battery Charging
The battery charger in the Trace DR series inverters, charges in three stages - BULK, ABSORPTION,
and FLOAT - to provide rapid and complete charge cycles without undue battery gassing. A manually
operated equalize stage is provided for periodic battery maintenance. The time diagram at the bottom
of this page shows how DC voltage and AC current change with time through the different charge
stages.
Stage One - Constant Current (Bulk Charge)
This stage is initiated when AC is applied to the AC input of the inverter, and is terminated when the
batteries reach the BULK CHARGE VOLTAGE. During this stage the Charger LED glows steady
orange.
Stage one charges the batteries at a constant current. The level of charge for this phase is set using
the BATTERY CHARGER RATE control on the front panel.
Stage Two - Constant Voltage (Absorption Charge)
Absorption is initiated when the Bulk Voltage setting is reached. At this point the charge current begins
to taper off at whatever rate is required to hold the voltage constant. During this stage the Charger
LED blinks orange. The absorption charge phase is terminated in one of two ways.
1. Normally, as the charge cycle progresses, the current required to hold the battery voltage
constant gradually reduces. When this current equals the programmed return amps setting
(battery bank capacity/40), the voltage is allowed to fall to the FLOAT (float voltage) setting stage three.
2. If there are DC loads on the batteries, the current may never fall to a level low enough to
initiate the float voltage stage. A timer is used to ensure that the battery voltage does not
remain indefinitely at the Bulk Charge Voltage. The timing circuit is activated by the onset of
stage two, it terminates stage two if the charge current does not reach the return amps value
setting within 12 hours.
Stage Three - Maintenance Voltage (Float Charge)
The charger remains in the float stage until the unit is turned off or loses AC input power (i.e. generator
or grid). During this stage the Charger LED glows steady green. The purpose of stage three is to
maintain the batteries at a voltage that will hold full charge but not gas the batteries.
Note: When DC loads are placed on the battery, the charger will deliver currents up to the Maximum
Charge Rate setting while maintaining the float voltage.
Bulk Charge Absorption Charge Float Charge
Charging
Bulk Volts Setting
Starte
Float Volts Setting
Absorption Time
DC Voltage
Battery Charge
Rate
3- Stage Battery Charger
DC Voltage and AC current
Charge Profile
AC Current
Constant Current
Constant Voltage
Reduced Current and Voltage
Time
Trace Engineering DR Series Owner’s Manual - Version 3.2 - 9/7/98 - Page 11
Battery Charger Controls and LED
Indicator
A three state LED reports on the activity of the battery charger. Controls are provided that make it
simple to tailor the charger’s characteristics for various types of batteries.
Charger LED
Labeled “CHARGER: GRN=FLOAT/ORN BLINK=ABSORP/ORN= BULK”, this bi-color LED indicates
charge status as follows:
•
Orange - this indicates that the charger is in the bulk charging stage.
•
Blinking Orange - this indicates that the charger is in the absorption stage.
•
Green - this indicates that the charger is in the float stage.
Note: The bi-color LED used has the ability to show red, green, or orange in color. By
simultaneously showing red and green the orange color is obtained. To avoid confusion as to
which color is being displayed, view the LED from directly in front of the unit. Do not view it at
an angle.
Battery Charger Rate
This control sets the maximum charge rate in amps. The highest charge rate recommended is
determined by dividing the battery bank’s total amp hour capacity by a factor between 3 and 5 (3
for gel cell - 5 for lead acid). Setting the BATTERY CHARGER RATE at the highest
recommended level is best when the objective is to charge the batteries as quickly as possible. A
much lower setting can be used in installations where AC power is typically available for periods of
several hours. For example: there is more than sufficient time for a 400 amp/hr battery bank to be
recharged in 24 hours at a 25 amp setting - 25 amps X 24 hours = 600 amp-hours.
Caution: Excessively high charge rates can overheat a battery. If a small battery capacity is used,
set the battery charger rate to the minimum setting.
Trace Engineering DR Series Owner’s Manual - Version 3.2 - 9/7/98 - Page 12
Battery Type Selector
This control automatically sets the correct bulk and charge voltages according to the type of battery
selected. The switch has ten positions. Each position provides different charge parameters. Select the
correct position according to the following table. (See the section “Battery Charger Setting” on the
next page, for specific applications and hints.)
12 VOLT MODELS 24 VOLT MODELS
Switch
Position
0 Equalize 1 13.2 15.0 26.4 30.0 c/40
1 Equalize 2 13.2 15.5 26.4 31.0 manual
2 Deep Cycle Lead Acid 2 13.3 15.0 26.6 30.0 N/A
3 Not Specified 13.6 14.3 27.2 28.6 N/A
4 Gel Cell 2 13.7 14.4 27.4 28.8 N/A
5 Gel Cell 13.5 14.1 27.0 28.2 N/A
6 PbCa- Lead Calcium 13.2 14.3 26.4 28.6 N/A
7 Deep Cycle Lead Acid 13.4 14.6 26.6 29.2 N/A
8 NiCad 1 14.0 16.0 28.0 32.0 N/A
9 NiCad 2 14.5 16.0 29.0 32.0 N/A
Table 2, Bulk, Float, and Equalize Voltages for DR Series Inverters
Position 0 and 1 - These positions may be used to equalize lead acid batteries. Equalizing is
discussed in the next chapter “Batteries”. These positions are unique in that the batteries are held at
the bulk voltage for a minimum of six hours. Position 0 equalizes at a rate equal to the battery capacity
in amp hours divided by 40. Position 1 charges at a rate set by the BATTERY CHARGER RATE
control. DO NOT USE THESE POSITIONS WITH SEALED BATTERIES!
Position 2 - Provides different bulk and float settings for deep cycle lead acid batteries as
compared to position 7. Consult the battery manufacturer for recommended bulk and float
settings.
Description Float
Voltage
Bulk
Voltage
Float
Voltage
Bulk
Voltage
Equalize
Rate
Position 3 - Provides an additional set of bulk and float voltages.
Position 4 - Recommended for gel cell batteries that specify high float voltages. Check with the
battery’s manufacturer.
Position 5 - Typical gel cell setting.
Position 6 - Use this setting for sealed type car batteries.
Position 7- Factory setting for typical deep cycle lead acid batteries.
Position 8 - For use with NiCad battery systems. See the following section “Batteries” for alternate
recommendations when using NiCads.
Position 9 - Recommended for use with Nickel Iron batteries.
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