The MM12 Underground/Underwater Resin Casting Waterproof Cable Junction Box is a cast resin straight-through joint engineered for polymeric cables and conductors. Designed for harsh installation environments, it serves commercial users across municipal engineering, water conservancy, industrial facility construction and outdoor power distribution projects. The product supports both compression and screw connectors on copper and aluminium conductors, adapting to varied on-site construction conditions and low-voltage cable connection demands.
This junction box features compact dimensions, fitting installation in narrow spaces such as cable ducts and buried pipelines. Its transparent shockproof plastic shell keeps the splice area visible before casting, allowing construction personnel to confirm connection status before resin pouring and reduce rework risk. The product is designed with a large filler aperture, which streamlines resin casting operation and cuts down on-site construction time. Its split mould structure enables quick assembly, which saves working hours and reduces labor costs for commercial projects.
The cable junction box resists chemical agents and alkaline earth elements, maintaining stable performance when exposed to soil and corrosive substances. Its material is stabilized against UV rays, supporting long-term outdoor deployment without performance degradation. The product achieves longitudinally and transversely water-tight performance, adapting to underground burial and underwater immersion scenarios, and preventing water ingress from damaging internal cable connections.
This resin casting joint delivers electrical insulating properties compatible with 0.6/1kV low-voltage systems, supporting stable operation of cable lines. It has high mechanical strength, protecting internal cable splices from external extrusion and impact during burial and installation. The product supports immediate operation after resin casting, which helps shorten overall project construction cycles.
This waterproof cable junction box applies to a wide range of scenarios, including indoor premises, outdoor facilities, underground burial, underwater environments and installation ducts. It fits low-voltage power distribution systems, outdoor lighting circuits, underground municipal cable networks, underwater landscape facilities and industrial plant wiring projects. The product is universally suitable for connecting polymeric cables or conductors insulated with PVC, PE, XLPE and EPR (e.g. N(A)YY, NYM, TT). It works with both copper and aluminium conductors, and supports compression or screw type connection terminals. The junction box has a rated voltage level of Uo/U (Um) 0.6/1 (1.2) kV, covering most low-voltage power distribution demands for commercial and industrial applications.
Remove steps from the end of the mould. The opening must be slightly larger than the cable diameter (approx. 1 - 2 mm).
Insert the cable sheath: for cable diameter φ ＜20mm, insertion length a = 2 × c; for φ ＞20mm, insertion length a = 40 mm.
Install connectors on cable conductors.
Roughen, degrease and clean the cable sheaths to ensure tight bonding with cast resin.
Centre the splice: the distance between the connectors, between the conductors themselves, and the distance of each splice from the mould must be at least 5 mm.
Snap the two mould halves together to fix the position.
Seal mould ends with PVC tape to prevent resin leakage during the pouring process.
Mix the cast resin and fill it in according to separate instructions, up to 3 mm from the upper edge of the filler opening.
Insert the cover onto the filler opening.
Energize the cables: cables with voltage up to 1 kV can be energized immediately after casting. For cables with core insulation made of PE, VPE, EPR and similar materials, add an extra step: roughen, degrease and clean the cable insulation before assembling the mould.
For PILC cables with armouring and jute: insert 20 mm of armouring into the mould; do not insert any jute section into the mould. For PILC cables with synthetic sheath: roughen, degrease and clean the cable sheath, then insert 20 mm of the sheath into the mould. Insert the lead sheath according to the insertion length rule described in step 2. Roughen, degrease and clean the lead sheath and armouring thoroughly immediately before locking the mould halves. Remove insulating material completely from the conductor and belt insulation. For fluid insulating material: cover the filler and paper insulation with Oilstop/Adhesive agent before resin casting.
CL | DIM | mm^2 | MXY(mm) |
MM10 | 6-19 | 5×2.5 | 160×36 |
MM11 | 6-25 | 5×6 | 190×48 |
MM12 | 14-35 | 4×16 | 240×50 |
MM13 | 16-37 | 4×25 | 270×65 |
MM14 | 20-44 | 4×50 | 360×80 |
MM15 | 26-52 | 4×95 | 430×95 |
MM16 | 35-65 | 4×150 | 530×120 |
MM17 | 45-80 | 4×240 | 700×180 |
The MM12 resin casting waterproof cable junction box has a rated voltage level of Uo/U (Um) 0.6/1 (1.2) kV, and it is designed for 1 kV and below low-voltage cable systems.
This product is compatible with polymeric cables insulated with PVC, PE, XLPE and EPR, as well as PILC cables. It fits both copper and aluminium conductors, and works with compression or screw connectors.
For cable systems with voltage up to 1 kV, the cables can be energized immediately after resin casting, with no additional waiting time required.
Yes. This cable junction box provides longitudinally and transversely water-tight performance, and resists chemical agents and alkaline earth elements present in soil. Its UV-stabilized material also adapts to outdoor exposure, making it suitable for long-term underground burial and outdoor installation.
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