Installation Manual

Page 44
© 2015 Sensata Technologies
Parallel Operation
4.4.3 Performing the Functional Test
After all electrical connections to the AC source, inverters, batteries, and remote (also main panel
and sub-panel, if applicable) have been completed, follow these steps to test the installation and
the inverters’ operation.
Testing Invert Mode
1. Prior to turning on the inverters, make sure all AC loads (i.e., appliances) are NOT connected
to the inverters’ output or to any AC outlets powered by the inverters.
2. Lightly press and release the Master inverter’s ON/OFF switch to turn on all of the inverters.
Verify that each inverter’s status indicator is blinking—indicating each inverter is on.
3. Connect a 10 to 25-watt light bulb to the inverters’ output, and then verify it comes on and
shines normally. DO NOT connect anything but a light bulb until all wiring and voltages are
confi rmed to be correct.
Info: The inverters’ AC output voltage will not be correct until a >5-watt load (5 watts
is default setting) is connected to the inverters’ output, or Search mode is turned off
with the router. The 10-watt or greater light bulb is used because it is a suffi cient load
to bring the inverters out of Search mode and up to full voltage.
4. Check the AC output voltage of the inverters by connecting an AC voltmeter to the output
terminals of the Master inverter (see Figure 2-17), and then verify the correct output voltages.
5. Press and release the Master inverter’s ON/OFF switch to turn off all of the inverters. Each of
the inverters’ status indicators and the connected load should go off.
Testing AC Transfer/Charge Mode
6. Apply AC power to the inverters’ AC input. After the AC input power is qualifi ed (approximately
15 seconds), the incoming AC power transfers through the inverters to the inverters’ AC output
and powers the light bulb. Verify that each inverter’s status indicator and the light bulb come on.
7. Even though the light bulb is on, the inverters are currently disabled (off). Press and release
the ON/OFF switch on the Master inverter to enable (turn on) all of the inverters.
8. Disconnect the incoming AC power to the inverters. Verify the light bulb remains on and is
now is powered by the inverters.
If the inverters pass all the above steps, your parallel-stacked inverter system is ready for use.
If the inverters fails any of the steps, refer to the Troubleshooting section.
4.5 Parallel Threshold Feature for MS-PAE Inverters
The router provides a parallel threshold setting for use with MS-PAE inverters in parallel-stacked
systems. This setting uses the percentage of power being provided by the master inverter as
the determining factor for when the slave inverters will turn on. When this setting is reached, all
connected slave inverters turn on at the same time to deliver maximum power to the loads. After
running approximately 30 seconds to stabilize the AC current, the slave inverter(s) that are not
needed shut down and the units that are still inverting equally share the AC current. Refer to your
router owner’s manual for more info on this feature.
Should I use the Parallel Threshold feature? Depends on the application. Most applications
set a threshold level such that the connected slave inverters come on only when required to power
the loads. This reduces the power drain on the batteries because the slave inverters that are not
actively powering the loads are in standby. However, if you have a load larger than the capacity
of the master inverter—and the startup current is needed very quickly—you may need to turn off
the threshold setting. This would ensure that all stacked inverters are always on to meet the fast
startup current requirements of a large load.
Where should I set the Parallel Threshold? Depends on your typical AC loads and how much
time you want the master inverter to run (versus the slaves). If you want the master inverter to run
as much of the loads as possible before the slave(s) turn on, then set the threshold at a higher
setting. If you want the slave(s) to share more of the load, then set the threshold to a lower setting.