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
PS Series Inverter/Charger
Part No. 3597
Rev. D: November 23, 1999
Page
85
SELLING POWER - STORED IN THE BATTERIES
Power stored in the batteries can also be sold into the utility grid. This can be used together with the solar
array or alone without a solar array. The inverter can be programmed to sell the energy in the batteries at
a specific time and then to recharge the batteries at another time. Both the discharge level and discharge
rate can be adjusted to control the battery selling process.
Selling the power stored in the batteries can be used to level the output of the combined solar array and
battery system. This is beneficial during conditions of cloudy weather when the solar array output will vary
with each cloud that passes over. To set-up this ability, adjust the SET BATTERY SELL VOLTS DC
menu item under the BATTERY SELLING (17) menu heading for the maximum discharge voltage level
acceptable. The SET MAX SELL AMPS AC menu item should be set for the expected maximum output
of the solar array. Next, access the GRID USAGE TIMER (18) menu heading to allow setting of the time
period that the battery will be allowed to recharge during by adjusting the SET START CHARGE TIME
and SET END CHARGE TIME menu items. Outside of this time period, the inverter will sell the power
stored in the battery to the utility grid until the voltage reaches the BATTERY SELL VOLTS DC setting.
This mode can use the battery to maximize the output of the system during a specific period of time. An
example of these setting follows:
Figure 27, Selling Power Stored in the Batteries; Hypothetical Time of Day Operational History
DC 14.4
DC Setting
Amps Setting
amps 20
AC amps
amps AC 00
{
Time
m 2:00
Amps Setting
amps AC 20
Volts DC 13.4
DC Setting
DC source (wind,
hydro or solar) has
started.
AC amps to grid (-)
AC amps from grid (+)
Volts DC 12.4
DC Setting
LEGEND
on SWRC
Volts DC 13.4
DC Volts
from grid has
started
has started
POSITIVE (+) = Inverter is drawing power
NEGATIVE (-) = Inverter is selling power to grid.
from grid has
stopped