19
©2001 Xantrex Technology Inc.
P/N 975-0027-01-01 Rev A 09/01
3.0 OPERATION
Over-Voltage Protection Using a Grid-Tie Inverter
Normally, the grid-tie inverter will regulate the charging process of the battery
by selling excess power into the utility grid. If the utility grid is not available (due to
an outage or tripped AC input circuit breaker, etc.) or if the inverter shuts off, the
inverter is not able to sell the excess power and the battery voltage will not be
regulated, resulting in possible overcharging of the battery.
Therefore, the ALM can be configured to provide over-voltage protection for the
battery when a utility outage has occurred. These relays can be configured to control
an externally connected, power relay that disconnects the solar array and stops the
charging process. The external relay can be either a standard mechanical type or a
mercury displacement type, depending on the voltage and current required. The
mercury displacement type relay is usually required when the system voltage is
48 VDC or if the current of the solar array exceeds about 20 amps. Multiple relays
can be used if the solar array is divided into several source circuits (do not parallel
relays for higher current).
A typical wiring configuration for this over-voltage protection is shown in
Figure 3-5.
This circuit does draw a small amount of power all of the time to power the coil
of the relay. This circuit provides protection against overcharging the batteries.
Photovoltaic
Array
+
-
BATTERY BANK
+
-
N.O.
N.C.
COM
ALM
Inverter
-
AC Output - Neutral
AC Output - Hot
+
N.O.
120 VAC
Coil
N.C.
COM
External Power Relay
Communications Cable
AUX
J1
Figure 3-5
Over-Voltage Protection using a Grid-Tie Inverter
Summary of Contents for ALM - REV A
Page 1: ...Owner s Manual Auxiliary Load Module...
Page 10: ...1 0 INTRODUCTION 2001 Xantrex Technology Inc P N 975 0027 01 01 Rev A 09 01 6 Notes...
Page 18: ...2 0 INSTALLATION 2001 Xantrex Technology Inc P N 975 0027 01 01 Rev A 09 01 14 Notes...
Page 26: ...2001 Xantrex Technology Inc P N 975 0027 01 01 Rev A 09 01 22 3 0 OPERATION Notes...
Page 28: ...4 0 TROUBLESHOOTING 2001 Xantrex Technology Inc P N 975 0027 01 01 Rev A 09 01 24 Notes...
Page 30: ...5 0 SERVICE INFORMATION 2001 Xantrex Technology Inc P N 975 0027 01 01 Rev A 09 01 26 Notes...
Page 32: ...6 0 WARRANTY 28 2001 Xantrex Technology Inc P N 975 0027 01 01 Rev A 09 01 Notes...
Page 34: ...7 0 SPECIFICATIONS 2001 Xantrex Technology Inc P N 975 0027 01 01 Rev A 09 01 30 Notes...
Page 35: ......