OPERATION
Copyright
Trace Engineering Company, Inc.
5916 - 195th Street N. E.
Arlington, WA 98223
Telephone: 360/435-8826
Fax: 360/435-2229
www.traceengineering.com
SW Series Inverter/Charger
Part No. 2031-5
Rev. B: Sept 1, 1999
Page
85
SELLING POWER - FROM A DC CHARGING SOURCE
The simplest and default operation of the SW Series Inverter/Charger in the SELL mode is to “sell” the
excess power from the charging source to the utility when the batteries are full. In this mode, the battery
voltage is held to the regulation level determined by the SET BATTERY SELL VOLTS DC setting. Since
the SET BATTERY SELL VOLTS DC setting is defaulted to the same value as the SET FLOAT VOLTS
DC setting, the inverter will sell the power from the charging source (wind, hydro or solar, etc.), but will
hold the battery at a charged level.
The regulation process can also be accomplished and allow the three stage charging (float, bulk and
absorption) of the batteries to occur each day by enabling the BULK CHARGE TRIGGER TIMER (15).
The batteries will be maintained at the SET FLOAT VOLTS DC setting until the SET START BULK TIME,
which will charge the batteries near the SET BULK VOLTS DC setting until the end of the ABSORPTION
TIME.
This operating mode offers the individual system owner with several advantages. The batteries would not
be cycled thereby increasing their life and the batteries would be fully charged in case of a power failure,
resulting in greater system efficiency.
Figure 27, Selling Power From A DC Charging Source; Hypothetical Time Of Day Operational History
Begin Day
00:00
Time
AC amps
20:00
End Day
23:59
DC Volts
13.0
Input
amps AC 00
{
AC amps from grid (+)
{
Set Start Bulk
time 20:00
Set Battery Sell
Volts DC 13.4
Float Volts
DC Setting
Battery Sell Volts
DC Setting
Bulk Volts
DC Setting
Bulk Charge Trigger Timer is
enabled (not the default setting)
Set Bulk Volts
DC 14.4
Charging from the DC
source (wind, hydro or
solar) has started
Absorption Time
Set Absorption
time h:m 02:00
Set Float
Volts DC 13.4
Charging from the DC
source (wind, hydro or
solar) has stopped
Sell to grid period
when the current from
the DC source is greater
than needed to maintain
the Float/Sell Volts DC
setting.
Set Max Sell
amps AC 30
Max Sell Amps
AC Setting
POSITIVE (+) = Inverter is drawing power from grid.
NEGATIVE (-) = Inverter is selling power to grid.
LEGEND
Information
Display/Settings
on Control Panel
Max Charge
Amps AC Setting
Set Max Charge
amps AC 30
AC amps to grid (-)
DC Volts
Battery
charging from
grid has
started
Summary of Contents for SW II - REV 4.01
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