Product Manual

Configuration
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Peak Load Shaving (PLS)
Many utilities impose a surcharge on their customers based on the peak load
used by a facility. To reduce utility peak demand charges, the inverter can be
configured (using the Load Shave Amps setting) to limit the maximum draw the
AC loads place on the utility. The inverter can be programmed to provide power
above a specified level to avoid the surcharge. When the utility current draw
reaches the maximum level, the inverter assists by sourcing power from the
batteries to the loads.
For PLS to be effective, all loads must be connected to the inverter. For large
loads, multiple (or stacked) inverters may be required.
To help the batteries supplement the power requirements of the connected load,
an additional source of power (solar, wind, or hydroelectric) is recommended.
The default PLS setting for Time in Float is zero. In this case, PLS is only entered/
exited as programmed within the time window.
When the Time in Float is different than zero, PLS shall start only if the battery
amperage remained at the specified level for the configured time.
Example: Load Shave=Enabled, LoadShaveAmps=10 A,
LoadShaveStart=6:00pm, LoadShaveStart=9:00pm, Time in Float=60 min,
PLS Dly 2h= Enabled.
With these example settings, the Conext XW+ would enter PLS within the
configured window of time only if the battery was charged from MPPT in Float
(including Absorption) for 2 hours.
Time-of-Use Metering
Utilities use time-of-use metering to determine utility charges during peak usage
hours and to impose a surcharge. The Conext XW+ can be configured (using the
Load Shave Start, Load Shave Stop and Charger Block settings) to overcome
these peak charges by using utility power to charge the battery bank during the
inexpensive energy hours and consuming the battery energy during expensive
energy hours.
For example, if Charger Block is set between 9:00 AM and 10:00 PM and Load
Shave is set between 6:00 PM and 9:00 PM, charging on AC1 stops at 9:00 AM
and continues to pass utility AC through to the loads. If charging is required
during the charger block period, and AC Priority is set to AC2, the Conext XW+
can use any AC source connected to AC2. Loads will transfer to the AC source
on AC2 as well. The inverter connects to the utility grid at 6:00 PM and supports
loads using the batteries. The inverter continues to run until 9:00 PM. The Conext
XW+ then stops supporting the utility grid and passes utility AC through to the
loads. At 10:00 PM utility AC begins maintaining the batteries based on the
battery charger settings.
The above example allows an external renewable energy source to be utilized as
a primary charging source during a desired time window. The charger
(using utility AC connected to AC1) can then be used to supplement the battery
charging when the utility rates are low.
XW_Operation.book Page 32 Wednesday, August 12, 2015 2:39 PM