Projoy 1000V DC Junction Box 2 String MC4 | PEJB-2-1-MC4

The Projoy PEJB-2-1 is a 1000V DC junction box for photovoltaic systems, built to combine and protect two PV strings into one output in a single wall-mounted enclosure. This version is supplied for MC4 connector input and output, so strings plug straight in with standard solar connectors. Each box integrates a DC switch disconnector, DC surge protection and DC fuse protection in an IP65, IK10 enclosure. It lets you isolate the array for inspection and maintenance and limits the impact of a fault on the rest of the PV system. Designed for residential rooftop PV plants with up to 4 strings. 1000 V DC Max voltage 32 A Rated current 2 In / 1 Out Strings IP65 Enclosure rating IK10 Impact rating Type 2 DC surge protection DC safety PV modules generate DC voltage whenever they are illuminated, and opening the switch does not de-energise the cabling on the module side. Installation must be carried out by a competent person in accordance with BS 7671 (including Section 712 for solar PV systems) and the manufacturer's instructions. Fuse and string sizing The datasheet lists fuse links of 10 x 38 mm in a 15 A to 32 A range. Select the fuse rating to suit the module's maximum series fuse rating and the string short-circuit current. The two strings are combined onto one output, so both should use the same module type, orientation and tilt, and the combined current must stay within the 32 A maximum current output. Key features DC switch disconnector Isolates the array for maintenance and inspection. Rated 1000 V insulation, 32 A, category DC21B / PV1 to IEC 60947-3. DC surge protection Built-in Type 2 surge protector to IEC 61643-11 / EN 61643-31, with Ucpv 1000 V and 40 kA maximum discharge current. DC fuse protection Fuse holders for 10 x 38 mm fuse links (15 A to 32 A range) give overcurrent protection rated for 1000 V working voltage. Tough IP65 enclosure PC / ABS enclosure with IP65 ingress protection and IK10 impact resistance, described by the manufacturer as anti-fire, anti-UV, anti-impact and anti-corrosion. MC4 connections Supplied as the MC4 connector version, ideal for quick, standard PV connections. The manufacturer also offers 4 to 8 mm cable gland entry as the default option. Certified components Switch disconnector certified UL, TUV, SAA, CE and CB. Surge protector TUV, CE and CB. Fuse holder CB and CE. Technical specifications General Brand Projoy Series PEJB solar DC junction box Part number (MPN) PEJB-2-1-MC4 Base model PEJB-2-1 Input 2 strings Output 1 string Max voltage 1000 V DC Max current output 32 A Max DC short circuit current per input 15 A (changeable) Input / output terminals Cable gland (4 to 8 mm) or MC4 (this listing: MC4) Enclosure Material Polycarbonate / ABS Ingress protection IP65 Impact resistance IK10 Dimensions (W x H x D) 273 x 230 x 110 mm (12P) Installation Wall mounting DC switch disconnector Rated insulation voltage (Ui) 1000 V Rated current (Ie) 32 A Category DC21B / PV1 Standard IEC 60947-3 Certification UL, TUV, SAA, CE, CB DC surge arrester Type Type 2 Standard IEC 61643-11 / EN 61643-31 Max operation voltage (Ucpv) 1000 V Max discharge current 40 kA Certification TUV, CE, CB DC fuse Rated working voltage 1000 V Fuse link size 10 x 38 mm Fuse link range 15 A to 32 A Certification CB, CE Environment Operating temperature -20 °C to +60 °C Humidity Up to 99% Altitude Up to 2000 m Frequently asked questions What does the MC4 in the part number mean?The manufacturer lists input and output as either 4 to 8 mm cable gland or MC4 connectors. This listing, PEJB-2-1-MC4, is the MC4 connector version.How are the two strings connected?Two string inputs are combined into a single output pair, with a maximum current output of 32 A. This suits systems where two strings feed one DC input.What is the maximum short circuit current per input?The datasheet gives 15 A per input, marked as changeable. Check this against your module short-circuit current and fuse selection before installation.What size PV system is it designed for?The datasheet positions the PEJB-2-1 for residential rooftop PV plants with up to 4 strings.What fuses does it take?It uses 10 x 38 mm DC fuse links, with a 15 A to 32 A range given in the datasheet. Choose the rating to match your module and string design.Is it suitable for outdoor installation?Yes. The enclosure is IP65 and IK10 rated, made from PC / ABS, and is designed for wall mounting at operating temperatures from -20 °C to +60 °C. Mount it where the cable entries are protected and the switch is accessible for maintenance.