SMA STP 50-40 - Changing the Operating Mode of the Multifunction Relay

8 Operation
SMA Solar Technology AG
Operating manualSTP50-4x-BE-en-2380
This means that if the "Q on Demand 24/7" function" is active, no other grid-supporting functions
(e.g., cos phi) are possible between day and night operation of the inverter. Should an
independent reactive power provision be desired between day- and night operation, the reactive
power provision must be communicated to the inverter via a superordinate control unit.
Currently, the provision of reactive power can only be read off via the phase currents and phase
voltages in the instantaneous values (Instantaneous values > AC Side > Phase currents /
Phase voltage) or requested via Modbus.
The basic procedure for changing operating parameters is explained in another section (see
Section8.14, page77).
Procedure:
1. Select the parameter Reactive power mode in case of active power output and set the
desired procedure. When doing so, note that for "Q on Demand 24/7", the modes Cos
Phi(P) characteristic curve or Cos Phi(U) characteristic curve may not be selected.
2. Select the parameter Reactive power mode in case of zero active power and set the
desired procedure.
3. Set the parameters associated with the reactive power mode.
8.18 Changing the Operating Mode of the Multifunction
Relay
The default operating mode of the multifunction relay is Fault indication (FltInd) . If you decide to
use another operating mode and have established the correct electrical connection for this
operating mode and the associated connection variant, you will have to change the operating
mode of the multifunction relay and make other settings, if necessary.
The basic procedure for changing operating parameters is explained in another section (see
Section8.14, page77).
Procedure:
1. Call up the menu Device parameters.
2. Click on [Edit parameters].
3. In the parameter group Device > Multifunction relay > Operating mode select the
parameter Operating mode of multifunction relay or Mlt.OpMode and set the desired
operating mode.
4. In Self-consumption or SelfCsmp operating mode: In the parameter group Device >
Multifunction relay > Self-consumption > Minimum On power, select the parameter
Minimum On power for MFR self-consumption or Mlt.MinOnPwr and set the desired
value. This determines the power threshold at which a load is switched on.
5. In Self-consumption or SelfCsmp operating mode: In the parameter group Device >
Multifunction relay > Self-consumption > Minimum power On time, select the
parameter Minimum power On time, MFR self-consumption or Mlt.MinOnPwrTmm
and set the desired value. This determines the minimum time for which the power must exceed
the minimum switch-on power threshold before the load is switched on.