SMA SI 3.0-11 Installation - Manual (Page 77)

SMA Solar Technology AG 8 Commissioning
Installation Manual SI30M-44M-60H-80H-IA-en-30 77
Requirement:
☐ In a cluster, the Sunny Remote Control must be connected to the master.
Procedure:
1. Calculate the individual cable resistances. Use the following formula:
R
Cu
(l,A) = resistance of the cable
ρ = specific resistance of copper (ρ = 0.018 Ω mm² ⁄
m
)
l = total length of the conductor (outward conductor + return conductor = twice the cable length) in m
A = conductor cross-section in mm²
2. Calculate the total resistance of the battery cable. Use the following formula:
R
BatRes
= R
Cable 1
+ R
BatFuse
+ R
Cable 2
R
BatRes
= total resistance of the battery cable
R
Cable 1
= calculated resistance of cable 1
R
Cable 2
= calculated resistance of cable 2
R
BatFuse
= calculated resistance of BatFuse = 2 m Ω
3. Switch to expert mode on the Sunny Remote Control (see the Sunny Island inverter operating manual).
4. Select the parameter 221.06 BatWirRes and set to the resistance of the battery cable.
8.2.7 Setting the Control of the Battery Room Fan
1. Switch to installer mode on the Sunny Remote Control (see the Sunny Island inverter operating manual).
2. Select the parameter 221.07 BatFanTmpStr and set it to the battery temperature at which the fan is to be switched
on.
3. Ensure that the multifunction relay used for control is set to BatFan or MccBatFan (see Section 8.1.5 "Setting the
Functions of the Multifunction Relays", page 66).
4. Ensure that the battery room is sufficiently ventilated in the case of malfunctions – for example, on failure of the
multifunction relay.
8.3 Energy Management
8.3.1 Setting Load Shedding in a Multicluster System
The load contactor in the Multicluster Box is a load-shedding contactor and is controlled depending on the
state of charge of the batteries.
Significance of the SOC thresholds:
When the state of charge of a battery reaches the lower SOC threshold, the load contactor is opened. The state of charge
of the battery of the main cluster and the states of charge of the batteries of the extension clusters are evaluated. The load
contactor disconnects the loads from the stand-alone grid. When the state of charge of all batteries reaches the upper
SOC threshold during recharging, the load contactor closes. The load contactor connects the loads to the stand-alone
grid.
Requirement:
☐ The Sunny Remote Control must be connected to the master of the main cluster.
R
Cu
l A     l
A
----  =