SMA America, LLC
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Technical Description
SI5048U-TUS121440
121
Load Dependent Start
In case increased energy demands arise, the generator can be requested for support. This function
can be switched on or off (default) using the ”235.09 GnPwrEna” parameter. The function is only
effective if the ”235.01 GnAutoEna” parameter is simultaneously set to On.
The load limit for the request and the generator stop is configured using the ”235.10 GnPwrStr” and
”235.11 GnPwrStp” parameters. The average time by which an average value for the consumer
power is calculated can be set using ”235.12 GnPwrAvgTm”. This prevents temporary power
consumption peaks of a few seconds from causing a power-dependent generator start.
If the generator has been started due to the load, it runs according to the minimum generator run time.
If, once this time has expired, the average power is below the cutoff limit, the generator is stopped
again.
The following process diagrams provide an overview of the start/stop behavior of the Sunny Island
during automatic generator operation:
Reaching the floating charge process
If the float charging process (see section 13.4 ”Charge Control” (page 107)) is activated
before the cutoff limit (GnSocTm1Stp or GnSocTm2Stp) is reached, the generator request
is disabled again. If a full or equalization charge is active, the generator is only stopped
after this charge is completed and not when ”235.04 GnSocTm1Stp” or ”235.06
GnSocTm2Stp” is reached.
Multi-phase system
Only the total consumer power of all phases is monitored. Individual phases in a multi-
phase system are not monitored.
The consumer power is calculated using the inverter power (”111.01 TotInvPwrAt”
parameter) and generator power (”131.01 TotExtPwrAt” parameter).
