6 Electrical Connection
SMA Solar Technology AG
Operating manual
SI44M-80H-13-BE-en-15
48
Procedure:
1.
WARNING
Danger to life from electric shock due to incorrect insulation
In the case of faulty insulation, supposedly de-energized parts or cables may be live. Touching live components
or cables can result in death or serious injury due to electric shock.
• When making the following connections, always insert a silicone tube (see Section 6.6.5, page 60).
2. The default setting of the Sunny Island uses the multifunction relay
Relay1
for generator requests. Therefore,
connect the control cable to the multifunction relay
Relay1
on the Sunny Island. Use the
C
and
NO
connections.
3. If the multifunction relay
Relay1
for generator requests is not available, connect the control cable to the
multifunction relay
Relay2
on the Sunny Island. Use the
C
and
NO
connections.
4. If, with more than one Sunny Island, the multifunction relay
Relay1
and
Relay2
for generator requests are not
available on the Master, connect the control cable to a free multifunction relay on slave 1 or slave 2. Use the
C
and
NO
connections.
5. Enter the configuration
Automatic generator request
in the table of settings (see Section 7.10.2, page 102).
6.5.12 Connecting Load-Shedding Contactors
Relevant for off-grid systems
Load shedding prevents battery deep discharge and controls the supply of energy to the loads. Load shedding
provides the option of disconnecting specific loads from the system.
Load shedding is necessary for an off-grid system that is exclusively supplied with PV energy or wind energy.
The Sunny Island controls up to two load-shedding contactors depending on the state of charge of the battery. You
can install two types of load shedding:
• One-level load shedding
If the battery state of charge limit has been reached, one load-shedding contactor disconnects all loads at the
same time. Depending on the configuration, the load-shedding contactor closes when the battery has been
sufficiently charged or when the stand-alone grid has been switched to an external energy source.
• Two-level load shedding
In two-level load shedding, there are two thresholds for the state of charge of the battery in order to control two
load-shedding contactors. When the first threshold for the state of charge of the battery is reached, the first load-
shedding contactor disconnects a group of loads. When the second threshold for the state of charge of the
battery is reached, the second load-shedding contactor disconnects the remaining loads.
SUNNY ISLAND
NO
C
Relay 2
_
+
BatVtg
A1
A2
Relay
LOAD-SHEDDING
CONTACTOR
Figure 13: Connection of control cable for 1-stage load shedding (example)
