DC String Combiner Box 1 String 600V 16A with Isolator IP65
Single-string DC field combiner box (1 IN / 1 OUT) up to 600 V with isolator, to be installed between the modules and the inverter. It integrates a 32 A fuse holder, a 600 V DC isolator and a 600 V SPD surge protector, with input and output terminal blocks.
IP65 box with 8 DIN modules, components labelled on plastic-coated rails.
The QDC-01/01 SEZ DC field combiner box in the 600 V version protects and isolates a single photovoltaic string. It is installed between the module array and the inverter and brings together the three DC-side functions: isolating the string for maintenance, protecting it with a fuse holder, and discharging overvoltages to earth before they reach the MPPT.
The isolator (SEZ): why a fuse alone is not enough
The SEZ designation indicates an on-board DC isolator. The DC side has no zero crossing: opening a string under load with an unsuitable device generates an arc that does not extinguish by itself. The built-in isolator is rated for 600 V direct current and can be operated under load, making it possible to isolate the string safely without shutting down the whole system.
QDC-01/01-600V-16A SEZ technical specifications
| Configuration | 1 string IN / 1 OUT |
| Rated voltage | 600 V DC |
| String protection | 1 fuse holder with 32 A 1000 V DC fuse |
| Isolation | 1 DC isolator 600 V |
| Overvoltages | 1 SPD surge arrester 600 V |
| Connections | Input and output terminal blocks |
| Enclosure | IP65 box with 8 DIN modules |
| Weight | 4 kg |
Technical note: the designation states 16 A while the fuse holder is fitted with a 32 A 1000 V DC fuse. Confirm the actual rating against the Isc of your modules before ordering.
When to choose the 600 V version
The 600 V version is intended for short strings and for inverters whose MPPT does not exceed 600 V: some low-voltage hybrids, microinverters with a wide input range, and roof sections with few modules in series. The design constraint remains the open-circuit voltage (Voc) at the minimum temperature: with a 600 V ceiling the number of modules in series is lower than in a 1000 V system, so it must be checked carefully. If your system works at higher string voltages, choose the 1000 V version.
Frequently asked questions
What is the difference from the version without an isolator?
The SEZ version integrates the DC isolator that lets you isolate the string under load for maintenance. Without an isolator, isolation must be provided elsewhere, typically at the inverter input.
Can I use it on a 1000 V system?
No: the isolator and surge arrester of this version are rated for 600 V. For strings that exceed 600 V of cold Voc, the 1000 V version of the same series is required.
Is it suitable for outdoor installation?
The IP65 rating allows it. A position not exposed to the sun all day long is preferable: the internal temperature reduces the service life of the surge arresters.