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

Description

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.

BTU Calculator

BTU & WATT Calculator

Room Dimensions

Length (in m):

Width (in m):

Height (in m):

Room Type

Living Room

Bedroom

Kitchen

Bathroom

Conservatory

Hallway

Glazing Type

Single Glazed

Double Glazed

Triple Glazed

External Walls

0 Wall

1 Wall

2 Walls

3 Walls

4 Walls

Insulation Level

Poor

Average

Good (New Build)

Calculate

Required Heating

0

Watts

0

BTUs