• string.CB 16

string.CB 08|12|16|24|32

In large solar systems monitoring and troubleshooting becomes more complex. Each operator is interested in finding errors in a module, string, or a group quickly because they can reduce the amount of energy produced and the life of the system greatly.

With the help of the Generator Connection Boxes string.CB the individual solar module strands of a photovoltaic system can be connected in parallel and connected to larger wire cross sections to the inverter.

With the integrated string.bloxx it is possible to monitor and to control, inverter-independent precisely the DC side of photovoltaic systems. The data exchange between a string bloxx and superior management system can be direct, for example, the data logger Q.reader or the Controller Q.pac directly via the open standard Modbus RTU Bus. Thus, for example, a SCADA integration via OPC server without problems.

Key features

Channels 8, 12, 16, 24, 32 PV strings can be connected,
other versions available on request
VDC Layout Consistent 1000 VDC layout (option 1500)
Inputs Inputs for current, voltage and temperature
Overvoltage protection 1000 VDC and communication
Signal contact monitoring Circuit breakers and protective devices
Signal conditioning Calculated DC Power, linearization, mean value, Min/Max storage, alarm
Integrated LC display Display of all readings including current and
DC power for each string, configuration
RS485 fieldbus interface Up to 115.2 kbps: Modbus-RTU, (optional OEM)
Connectivity Can be connected to test controller and datalogger e. g. Q.reader oder Q.pac
Lever type switch fuse In positive pole with contact protection
DC load break switch Included
String connection terminals 1,5 - 10 mm2 (optional MC3, MC4)
Housing Heavy duty industrial quality material and workmanship,
IP65, UV and weather resistant, -35°C bis +80°C

Functional Scheme


Designstring.CB 08string.CB 16string.CB 24
DC Input
Number Inputs81624
Connection push in terminal connection 1.5-10 mm²
External diameter of the connecting cable Cable screw connection M16 4-10 mm (optional M20 6-13 mm)
Max. accepted DC input voltage 1000 VDC
Current measuring range ±26 A
Accuracy 0.25 %
Maximal accepted total current 125 A 200 A 315 A
Voltage measurement 0-1000 VDC
Accuracy 0.2 %
Fuses Lever release fuses in the plus and minus line
Current string fuses 2-20 A (optional)
Fuse dimensions 10 x 38 mm
Earth terminal 35 mm²
External diameter of the earth cable M20 grounding cabel (6,5-12,0mm)
DC Output
Maximum permitted total current125 A200 A315 A
Maximum output voltage 1000 VDC
Output terminal, copper plate with hole diameter 11 mm
Maximum connectable tube lug M10 unisulated
Maximum recommended cable300 mm²300 mm²300 mm²
Maximum permissible total current125 A200 A315 A
Temperature measurement
Type Pt1000 in 2 wire connection
Measuring range -40 up to +160°C
Connection 0.25 mm² - 1.5 mm² push-in spring-cage connection
Digital Input
Use Monitoring circuit breaker, DC and RS485 ÜSS
Number used/free3/03/33/6
Digital Output
Output State, alarm
Contact Relay change over contact
Load capacity 30 VDC/1 A (ohmic load)
Connection 0.25 mm² - 1.5 mm² push-in spring-cage connection
Auxiliary voltage
Input voltage range Direct connection 10 up to 60 VDC
Outside diameter of the connecting cable Gland M20 6 up to13 mm (M25 9 up to 17 mm option)
Connection Tension, cross section: 0.08 mm² up to 1.5 mm
Standard RS-485, 2 wire
Data format 8e1
Protocol Modbus-RTU, ASCII: 19.200 bps up to 115.200 bps
Number oft he devices on the bus max. 250
Connection 0.25 mm² - 1.5 mm² Push-In-spring-Connection
Outside diameter of the connecting cable Gland M20 6-13 mm (M16 4-10 mm option)
Maximum cable length 1200 m over active repeater expandable
Width incl. bracket650 mm650 mm650 mm
Height incl. bracket 850 mm
Depth incl. bracket 300 mm
Weight18 kg24 kg39 kg
Housing UV and weather resistant, glas fiber reinforced polycarbonat, RAL 7035 (lightgrey)
Protection according to EN 60529 IP 65
Class according to EN 61140 2
Overvoltage protection DC Side: Class II, Communication Cat. 3
Operating temperature -25°C up to +60°C
Storage temperature -40°C up to +85°C