Spelsberg Abox Pro 350-35 Junction Box, IP66/IP69

A 125 A junction box with a 5-pole terminal block for outdoor use

The Spelsberg Abox Pro 350-35/sw is a black glass-fibre reinforced polycarbonate junction box, 252 x 252 x 120 mm, fitted with a raised 5-pole screw terminal block for conductors up to 35 mm2. Spelsberg lists it for industrial environments and unprotected outdoor areas, with IP66/IP67/IP69 sealing and a VDE test mark under DIN EN 60670-1/-22.

Technical specifications

Selection and installation

The data sheet lists industrial environments and unprotected outdoor areas as installation locations, with IP69 sealing and UV resistance listed together. Listed accessories include cable glands in M20 and M40 and M50, double-membrane seals, a mounting plate, a standard rail, terminal blocks up to 35 mm2 and a mast or pipe fixing set. Choose glands for the cable diameter and keep their ingress rating at or above the box rating.

Accessory part numbers

The data sheet lists these accessories: cable glands KVR M20-MGM/sw (22702001), KVR M20-GDB/MGM/sw (22702101), KVR M40-MGM/sw (22704001) and KVR M50-MGM (22745001); double-membrane seals DMS M20/sw (26002001) and DMS M40/sw (26004001); mounting plate Abox MPI 350 (89513501); standard rail Abox 250/350 NS35 (89533501); terminal holder Abox 100 KH 2006 6 mm2 (89600601); terminal block Abox 250/350 KLS-25/35 mm2 (89643501); mast or pipe fixing set MABF 215-1 (89604001); and cover retainer TG DVS-42 (18200601).

The box is certified by VDE to DIN EN 60670-1/-22 (VDE 0606-1/-22) and carries DLG and DNV marks. It is supplied with four double-membrane seals for M40 (sealing range 17 to 28 mm) and a cover retainer, and the cover is sealable with a screw torque of 1.5 Nm.

For a metal enclosure compare the Rittal AX 9206.100, and see automation accessories.

Selection checks before specifying the Abox Pro 350-35

Start from the circuit, not the box. Confirm the load current and voltage against the 125 A and 690 V ratings, then count the conductors per pole and check them against the terminal block capacity in the table, remembering the 10 mm2 minimum cross-section. List the cables entering and leaving the box with their outer diameters, because these decide which knockouts are opened and whether the supplied M40 double-membrane seals or separate cable glands from the accessory list are the better fit. Finally, check that the internal space leaves enough bending room for large conductors; a box that is technically big enough can still be awkward to terminate if the cables are stiff.

Installation on walls, structures and outdoors

Fix the base to a flat surface through the internal fixing points so the seal is not distorted, or use the mast or pipe fixing set listed when mounting on a pole. Open only the knockouts you need, and where possible bring cables in from the side or underneath so that water does not run towards the entries. Strip and terminate conductors neatly, use wire-end ferrules on flexible conductors as the data sheet describes, and tighten the terminal screws to the values in the Spelsberg instructions. Before closing, clear any debris from the seal area, fit the cover and tighten the cover screws evenly to the stated torque so the sealing performance listed on the data sheet is maintained.

Inspection and maintenance

Junction boxes are often installed and forgotten, so add them to the periodic electrical inspection routine. During planned shutdowns, check that cover screws are still tight, that cable glands and seals are intact and that there are no signs of water inside. Look for discolouration around terminals, which can indicate a loose connection under load, and re-tighten connections according to the instructions once the circuit is isolated. Replace any seal or gland that has hardened or cracked rather than reusing it.

Outdoor service in Oman and the GCC

For rooftops, pipe racks, solar installations and coastal plants in the region, the UV resistance and wide ambient range on the data sheet are relevant, but heat still deserves attention. A dark enclosure in direct summer sun can become noticeably hotter than the surrounding air, so compare the expected internal temperature with the 24-hour average limit and, where practical, choose a shaded mounting position. Note too that the data sheet relative humidity values fall as temperature rises, which matters for humid coastal sites where condensation can form during cooler nights. Fine dust is best kept out by using correctly sized glands on every entry and keeping unused knockouts closed.

Records and labelling

Label each box with its circuit reference on the outside of the cover, and keep a simple record of which cables enter which knockouts. When the box is reopened years later, this makes fault-finding faster and reduces the risk of disturbing the wrong circuit during maintenance work.

Documents and quotation

The Spelsberg data sheet for product number 43502001 is attached and is the source of the figures above; the sheet itself states that its statements are without guarantee, so confirm any critical value with the current Spelsberg listing. Send the product number, the cable entries needed and the quantity through the quotation form for availability from Seven Star LLC.