In various box transformers, switchgear, and switchgear, most use cable down-entry wire structures. When it rains, water does not "flow up" on its own but is adsorbed onto the cable sheath and gradually climbs upward.

 

1. The real reason: not water flow, but water film + capillary + surface tension

 

You can think of the cable sheath as a wet rope:

 

- Rain, condensation, ditch moisture → The outer skin is covered with a water film

 

- The water film is continuous, not drop-by-drop

 

- Due to surface tension, water spreads upward along the outer skin

 

- With the addition of wind pendulum and vibration, the water will climb higher and higher

 

The result was:

The cable enters the cabinet from bottom to top→ and the water film climbs all the way up to the terminal terminal

 

2. The downstream line structure is naturally designed to "divert water uphill"

 

The lower incoming line looks like this:

 

- Cable trenches/ground (low)

 

- → Vertical upward

 

- → Access to high-voltage cabinets/transformers (from high places)

 

The cable sheath is a continuous slope, allowing the water film to climb along the slope all the way to the high-voltage terminal.

Gravity does make water want to fall down, but surface tension + capillary action is stronger and can hold the water upward.

 

3. Why is high voltage especially wary of this?

 

Low-pressure inlet water is prone to electric leakage and tripping;

Once a continuous water film is formed under high pressure, it is equivalent to:

A conductive path is laid directly on the insulated outer shell

 

High-voltage electricity follows this waterway

From cable terminals → water film → cabinet/grounding → creepy, flashover, and firing systems

 

4. What exactly is a waterproof curve for?

 

To make a U-shaped/inverted U-shaped drip bends, it is:

 

- Interrupt the continuous waterway

 

- Let water gather at the lowest point of the bend into droplets

 

- Water droplets are too heavy, surface tension cannot hold the water

 

- Directly drip it down

 

If water can't climb up, the high voltage can't carry the water to the electricity.

 

The reverse water bend of a cable joint (also called waterproof bend or drip bend) is a deliberately downward (or upward) curved or angular bend made near the cable joint. Its core function is to block water from flowing along the cable sheath into the joint, terminal, or inside the equipment, preventing short circuits, rust, and electric leakage.

1. Core Principles

 Water flows down along the surface of the cable sheath.

 The reverse water bend forms the lowest point; water flows here naturally drip and cannot flow upward beyond the bend.

 Essentially, it is a physical water cutoff, similar to a drip line under an eaves.

2. Standard Practice (Must be done outdoors / in humid scenes)

1. Location: About 15–30cm below the connector / equipment inlet

2. Shape: U-shaped or Ω-shaped bent downward (lowest point below connector/terminal)

 

Key points

 

o Bending radius complies with cable specifications (does not damage insulation)

o Firmly fixed after bending, no deformation or rebound

o Seal the pipe opening with sealing putty / waterproof tape

3. Role (Why It Must Be Done)

 Water ingress prevention: rainwater and condensate must not flow into connectors or terminals

 Corrosion resistance: Prevents joints from prolonged water immersion, oxidation, or heat burning

 Leakage / Short Circuit Prevention: Keep joints dry to enhance insulation and safety

4. Common scenarios

 Outdoor box transformers and distribution cabinets

 Wiring motors, pumps, and outdoor equipment

 Cable trays, wall-penetrating pipe openings, and underground well joints

 Outdoor electrical equipment such as photovoltaics, charging stations, and street lights

 

Additionally, NKTEVA6 monitoring devices are installed inside the box transformer, equipped with built-in water sensors, cable flood alarms, and timely drainage for engineering personnel

It allows video capture to observe internal cables and connectors, and can also monitor whether cables and connectors are overheating

 

The intelligent distributed red array monitoring detector NKTEVA6 cable flood alarm comes with supporting software

The new version adds a flood alarm function (with built-in water immersion sensor), and a 90-degree red array field of view

Wide field of view makes it ideal for monitoring inside transformers/high and low voltage cabinets, as well as fire and fire monitoring in cable tunnel integrated utility tunnels 

 

Red Array video can be recorded and captured

The new Red Array offers a wider viewing angle of 90 degrees

Grid-powered / POE-powered fixed installation

Red Array has a faster response speed

A single upper computer workstation can run multiple monitoring software sets simultaneously

Online Kuajie Browsing

Windows computer, ANDROID phone

Mobile browsing is faster

 

TS501-94 distributed red array detector

TS501-95 Red Array controller 8-port / 16-port

 

 

 

 

 

Comes with built-in LEDs

 

 

NKTEVA6 Instructions for Using the Distributed Red Array Detector Monitoring Software 2025 Edition

 

No software installation required, does not occupy the registry, is safer, uses less system resources, runs faster and runs immediately after extraction

 

 

 

 

1 Red Array monitoring graphical management software 1 set Over-temperature alarm and cable flood alarm

(One host computer workstation can install multiple software packages and run simultaneously)

2 Red Array Controller NKTP 1 unit . Each NKTP Red Array controller has up to 24 RJ45 ports for power supply and communication

3 Distributed Red Array Detector NKTEVA6 1 unit Built-in water seepage sensor, 256 × red array detector 192. Field of view 90 degrees

(Supports browsing and settings on Windows computers and ANDROID phones)

 

 

Real-time capability, continuity, and a more user-friendly RJ45 network power interface make wiring simpler and relatively safer

It is very suitable for large-scale network systems

Wide field of view makes it ideal for monitoring inside high and low voltage cabinets as well as fire and fire monitoring in cable tunnel integrated utility tunnels

  

 

Providing advanced red array detection temperature imaging video monitoring solutions for on-site condition monitoring:

 

Equipped with a brand-new VOx detector to distinguish more details; 25Hz frame rate network interface; More advanced Matrix III image algorithm;

 

Reduces size and power consumption, making installation easier; Compatible with multiple industrial protocols, easily enabling automatic alarms and compatible with power monitoring SCADA interconnection