SMA SC 500HE-US - Manual (Page 53)

SMA America, LLC 9 Grid Monitoring
Operating Manual SC500HEUS-eng-BE-BUS120320 53
Figure 20: Parameters for monitoring the power frequency
The UL certification permits the first limiting value for the underfrequency and the associated time
period to be changed within the stated range. This means that you can set the first limiting value of
the underfrequency in the range from 57.0 Hz to 59.8 Hz and you can set the associated time period
in the range from 160 ms to 300 000 ms.
Example: Behavior of the inverter in the event of underfrequency
The first limiting value for the underfrequency is defined in the parameter "HzCtllLim" and is 59.3 Hz.
The associated period is set to 160 ms in the parameter "HzCtllLimTm". The second limiting value
for the underfrequency is defined in the parameter "HzCtlllLim" and is 57 Hz. The associated period
is set to 160 ms in the parameter "HzCtlllLimTm".
The power frequency falls to 59 Hz and has therefore fallen below the first underfrequency limit.
The inverter waits 160 ms. If the power frequency does not increase above the first limiting value
within this period, the inverter disconnects from the power distribution grid.
Parameters Explanation Default value
"HzCtllLim" The first limiting value of the underfrequency 59.3 Hz
"HzCtllLimTm" Time period for the first limiting value of the underfrequency 160 ms
"HzCtlllLim" The second limiting value for the underfrequency 57 Hz
"HzCtlllLimTm" Time period for the second limiting value of the
underfrequency 160 ms
"HzCtlhLim" The first limiting value for the overfrequency 60.5 Hz
"HzCtlhLimTm" Time period for the first limiting value for the overfrequency 160 ms