Application of sealing modules in substation cable fire protection systems

In substations, the sealing modules of cable fire protection systems are a crucial barrier to prevent the spread of fire along cable channels and ensure the safe operation of electrical equipment. Their core function is to prevent the spread of heat, smoke, flames, and toxic gases through cable penetrations (such as walls, floors, and control panels) during a fire, ensuring the integrity of fire compartments.

1. 1. Typical Application Scenarios and Risks of Sealing Modules for Fire Protection Systems of Substation Cables

📌 Key Pain Points:

Unsealed through-holes account for more than 70% of the fire spread paths in the substation;

Material aging and failure: Ordinary fireproof putty loses its sealing properties after drying and cracking;

Maintenance difficulties: Adding or removing cables requires breaking the existing seals.

1. 1. Key Standards and Specifications for Sealing Modules of Substation Cable Fire Protection Systems

🔥 International/National Standards

⚠️ Important Update: GB 23864-2023 has added EC grade materials, which are required to pass the thermal shock test (1000°C water spray cooling cycle).

III. Mainstream Sealing Module Types

▶ 1. Intumescent fire-retardant module

Material: Inorganic composite material (expanded vermiculite + silicate);

Principle: It expands 3-5 times when exposed to fire, forming a dense, heat-insulating carbonized layer;

Advantages:

It can cut and drill holes, adapting to irregularly shaped holes;

Supports the addition or removal of cables later;

Fire resistance ≥3h (EI180).

Representative products:

3M Fire Barrier Module;

Tyco CP 606.

▶ 2. Flexible fireproof bag (fire-retardant bag)

Structure: Fiberglass cloth wrapping the expansion material;

Applicable to: temporary sealing or large holes (>300mm);

Limitations: It is prone to settling with long-term use and requires regular inspection.

▶ 3. Modular sealing system (integrated fireproofing + EMC)

structure:

[Galvanized steel frame] → [Fireproof sealing module] → [EMC shielding layer] → [Compression device]

Function:

Simultaneously meets the requirements of fire resistance (EI120) and electromagnetic shielding (≥60dB);

Suitable for DCS cabinet incoming lines in intelligent substations.

Representative product: TST SEAL sealing module .

▶ 4. Fireproof sealant/fireproof putty

Suitable for: filling small holes (<50mm) or gaps;

Note: Low-smoke halogen-free (LSOH) type must be selected to avoid the release of toxic gases such as HCl.

1. 1. Key Technical Indicators for Selecting Sealing Modules for Substation Cable Fire Protection Systems

❌ Strictly prohibited:

Ordinary cement mortar (non-expanding, prone to cracking);

Halogenated fireproof putty (releases highly toxic gases in fires).

1. 1. Installation and Acceptance Key Points
   2. Construction process

The edges of the holes were cleaned thoroughly, free of oil and dust;

The joints between modules are sealed with a special fireproof sealant;

The gap between the cable and the module should be ≤5mm. If it exceeds this limit, fireproof foam should be used to fill it.

1. 2. Acceptance Testing

1. 1. Typical Engineering Case of TST SEAL Sealing Module for Substation Cable Fire Protection System

TST SEAL recommends: The selection of fireproof sealing modules for substation cables must adhere to the following principles.

🔥 The “Three Highs” Principle:

High fire resistance (EI120 and above);

Highly environmentally friendly (low smoke, halogen-free, ZA₂ grade);

High maintainability (supports cable addition and removal).

Negligence is strictly prohibited: Unsealed or poorly sealed through holes will become “death tunnels” in a fire, causing the entire station to be paralyzed.

For the “GB 23864-2023 Fireproof Sealing Material Selection Comparison Table” or specific product solutions and construction videos, please contact TST SEAL via email.