2.0 INSTALLATION
© 2001 Xantrex Technology Inc. All Rights Reserved.
P/N 975-0013-01-01 Rev B 10/01
9
Series Stacking (continued)
The STACKING port allows two SW or PS Series inverter/chargers to be used in the same system in a “SERIES”
configuration to operate 240 VAC loads. Series stacking can also be used to connect to 240 VAC only power systems
providing both 120 and 240 VAC outputs. A series stacking interface cable (SWI) is required to connect the series
stacking port of the inverters. In this mode the inverters act independently of each other; however their output is
phase locked and synchronized 180 degrees out-of-phase. Both units can independently charge the batteries or
provide battery backup power during a utility outage. 230 VAC/50 Hz units can not be stacked.
NOTE: Use tape to label the inverters as INVERTER 1 (L1) and INVERTER 2 (L2), for future
reference.
Series Stack DC Wiring (one disconnect device)
When stacking two inverters using one DC disconnect device, connect the units and batteries as follows:
• Tie the inverter’s negative terminals together using an appropriate length of cable (sized to fit).
• Connect one of the inverter’s negative terminals to the negative terminal of the battery bank.
• Tie the inverter’s positive terminals together using an appropriate length of cable (sized to fit).
• Connect one of the inverter’s positive terminals to the DC disconnect.
• Connect the DC disconnect to the positive terminal of the battery bank.
• Connect the Series Stacking Cable (SWI) to the STACKING port of both inverters.
• Connect the DC chassis ground lugs of both inverters together using a heavy gauge wire.
• Connect the negative end of the battery bank to a solid earth ground (refer to inverter installation manual).
NOTE: Connect the positive and negative wires to the batteries as show in the illustration
below. This ensures an even charge and discharge through the battery bank.
Figure 2-3
Series Stacking Using One DC Disconnect (Block Diagram)
+
+
DC
Disconnect
Negative
Tie
Series Stacking
Cable (SWI)
+
–
+
–
+
–
+
–
Positive
Tie
Inverter 1 (L1)
Inverter 2 (L2)
NOTE: Series Stacking
Cable connects on AC
side for SW inverters
–
–
DC Ground
Chassis Ground
