How to properly crimp SIP-16: tools, technology and common mistakes

Self-supporting insulated wire SIP-16 widely used for installation of overhead power lines with voltage up to 1 kV, including connecting private houses, garages and car repair shops. However, incorrect crimping of contacts can lead to overheating, oxidation and even circuit breakage - this is especially critical for lighting systems in parking lots, workshops or charging stations for electric vehicles. In this article we will look at how to professionally crimp SIP-16, which tool to choose and what to pay attention to when working with aluminum conductors.

The main difficulty when crimping SIP-16 associated with the material of the cores - aluminum requires more compression force than copper, and is also prone to “yield” under pressure. This means that even a well-crimped contact can weaken over time if the peculiarities of thermal expansion are not taken into account. We will consider not only standard sleeves and press jaws, but also alternative methods (for example, punctures or bolt clamps), which are sometimes used in the field.

1. What is SIP-16 and where is it used

SIP-16 - this is a self-supporting insulated wire with a core cross-section 16 mm², designed to transmit electricity over overhead lines. Unlike SIP-4 (where all the cores are insulated), at SIP-16 The carrier core is usually bare, and the phase cores are covered with light-stabilized polyethylene. This wire can withstand mechanical loads up to 1000 N and is used:

• 🏡 To supply electricity to private houses and garages (from power line support to the shield).
• 🔌 Street lighting connections (parking lots, car service areas).
• ⚡ Installation of temporary lines at construction sites.
• 🚗 Organization of charging stations for electric vehicles (if the power is up to 15 kW).

Important: SIP-16 not suitable for underground installation - for this use armored cables like VBBShv. Also, it cannot be used indoors due to flammable insulation (class NG does not apply to this type of wire).

⚠️ Attention: When connecting a garage or workshop via SIP-16 be sure to install RCD with leakage current no more 30 mA — aluminum conductors are more susceptible to insulation breakdown due to mechanical damage.

2. Tools for crimping SIP-16: what to choose

High quality crimp SIP-16 impossible without a specialized tool. Main options:

Tool	Crimping type	Pros	Cons
Hydraulic press jaws (for example, KBT HM-16)	Sleeves AMG, GAM	Even force, suitable for aluminum	Dear, requires skill
Mechanical crimpers (for example, IEK PC16)	Sleeves GSI, tips	Budget, compact	Uneven pressure over large sections
Piercing clamps (for example, Ensto Sliw 16)	Without stripping	Fast, no stripping required	Less reliable contact
Bolt connectors (for example, ZOI 16-35)	Threaded connection	Reusable	Requires regular checking of tightness

For SIP-16 the optimal solution is hydraulic press jaws with a hexagonal matrix - they provide uniform compression along the entire perimeter of the sleeve. Mechanical crimpers are suitable for one-time work, but with frequent crimping, aluminum may “leak” due to weak pressure. Puncture clamps are useful for branch lines, but are not recommended for main lines due to the risk of oxidation.

⚠️ Attention: Never use for crimping SIP-16 standard copper ferrule pliers (e.g. PC-16m) - aluminum requires 1.5–2 times more compression force, otherwise the contact will be unreliable.

Tip: If you are working with SIP-16 in frost (below -10°C), warm up the sleeves and wire with a hair dryer - aluminum becomes brittle in the cold, and crimping can damage the wires.

3. Selection of sleeves and tips for SIP-16

For crimping SIP-16 two types of connecting elements are used:

1. Aluminum-copper sleeves (GAM) - for connecting aluminum to copper (for example, when connecting to a copper cable in a panel). Marking: GAM-16.
2. Aluminum sleeves (GA, AMG) - for connecting aluminum to aluminum. Marking: GA-16 or AMG-16.

Key parameters when choosing:

• 🔹 Material: For SIP-16 Only sleeves with markings are suitable A (aluminum) or AM (aluminum copper). Copper sleeves (GM) cannot be used!
• 🔹 Section: Must match the wire cross-section - 16 mm². Sleeves GA-10 or GA-25 won't fit.
• 🔹 Insulation type: For street work, choose sleeves with heat-shrinkable tube (for example, 3M Scotchcast).

Critical error: using cases without anti-oxidation paste (for example, Quartzgel) leads to an increase in contact resistance by 30–50% after just 6 months of operation. The paste is applied in a thin layer to the wires before crimping - it displaces moisture and prevents corrosion.

Strip the insulation to 30–40 mm (use a knife with a limiter)

Apply anti-oxidation paste to the cores and the inner surface of the sleeve

Check the cross-section of the sleeve and wire for compliance

Make sure the liner is not cracked or deformed-->

4. Step-by-step instructions: how to crimp SIP-16

Let's consider the crimping process using the example of a connection SIP-16 with aluminum sleeve GA-16:

1. Stripping the insulation.

   Remove the insulation from the cores 35–40 mm special knife for SIP (for example, NWS-3). Do not use a lineman's knife - it can cut the wires! After stripping, twist the wires into a bundle and cut off the protruding ends.

2. Preparing the sleeve.

   Apply antioxidant paste on the inner surface of the sleeve and on the stripped conductors. Insert the wires into the sleeve until they stop - they should come out on the other side. 5–10 mm.

3. Crimping with hydraulic pliers.

   Install the sleeve into the die of the pressing jaws (for example, KBT HM-16) and squeeze with force 10–12 tons. Make two crimps, one at each end of the sleeve. The hexagonal profile of the matrix should leave clear hexagonal prints on the sleeve.

4. Connection isolation.

   Slide onto the sleeve heat-shrinkable tube (for example, TUTng 25/10) and warm it up with a hairdryer. Alternative - SIP caps (for example, Ensto Sliw Cap).

Checking crimp quality:

• 🔧 The sleeve should not scroll on the wire.
• 🔧 There should be no cracks or dents on the surface of the sleeve.
• 🔧 Contact resistance (measured with a multimeter) should not exceed 0.001 Ohm.

What to do if there are no hydraulic clamps?

As a last resort you can use mechanical crimpers with an effort of no less 5 tons, but then:

1. Make 3-4 crimps instead of two (in 5mm increments).

2. Check the connection for rupture - it must withstand a force of at least 50 kg.

3. Crimp the sleeve again after 2–3 months (aluminum “shrinks”).

5. Typical mistakes when crimping SIP-16 and how to avoid them

Even experienced electricians sometimes make mistakes that shorten the life of the line. Let's look at the most common ones:

Error	Consequences	How to avoid
Insufficient crimping force	Contact overheating, insulation melting	Use hydraulic pliers with pressure gauge
No anti-oxidation paste	Corrosion, increase resistance	Apply paste Quartzgel or NOX-IDEAL
Using copper sleeves	Electrochemical corrosion, breakage	Choose sleeves with markings A or AM
Crimping without stripping oxides	High contact resistance	Strip the veins steel brush before crimping

The error with twisting of veins before crimping. Many electricians twist wires “for reliability,” but this leads to:

• 🔥 Local overheating at the twisting site (due to increased resistance).
• 🔧 Loosening of the crimp - the cores can “slip” out of the sleeve.

⚠️ Attention: If after crimping the sleeve appears microcracks, the connection must be replaced - even with normal resistance, such sleeves burst under temperature changes.

6. Alternative methods for connecting SIP-16

In addition to crimping with sleeves, for SIP-16 use:

Piercing clamps

Used for branches without breaking the main line. Popular models:

• 🔹 Ensto Sliw 16 - for branches up to 50 A.
• 🔹 Niled SLIP 16 - with UV protection.

Pros: do not require stripping of insulation, installation within 2–3 minutes. Cons: less reliability at high loads (more than 30 A).

Bolt connectors

Suitable for temporary lines or repairs. Example: ZOI 16-35. Features:

• 🔧 Requires regular checking of tightness (once every 6 months).
• 🔧 Not airtight - needs additional insulation heat shrink.

Welding cores

Rarely used for SIP-16 due to the complexity of the process, but provides the most reliable connection. Use spot welding machines (for example, TS-700) with graphite electrodes. Suitable for professionals only!

7. Maintenance of crimped connections

Even crimped correctly SIP-16 requires periodic monitoring. Recommendations:

• 📅 Every 6 months: Visual inspection for absence of melting or insulation cracks.
• 📅 Once every 2 years: Checking the contact resistance with a multimeter (should be no more than 0.01 Ohm).
• 📅 In case of strong winds/icing: Wire tension control - sagging more 50 cm on the fly 25 m requires a lift.

Signs of a connection failure:

• 🔥 Darkening or melting of the sleeve insulation.
• 🔊 Crackling under high load.
• 🌡️ Local heating (measured pyrometer).

If defects are found, the connection must be re-crimped. In 80% of cases problems arise due to:

1. Poor quality stripping of veins.
2. Lack of antioxidant paste.
3. Using unsuitable sleeves (e.g. GM-16 instead of GA-16).

FAQ: Frequently asked questions about crimping SIP-16

Is it possible to crimp SIP-16 with ordinary pliers?

No! The pliers do not provide the required force (at least 5–10 tons), and the contact will be unreliable. As a last resort, use mechanical crimpers with a hexagonal matrix, but only for temporary connection.

What is the service life of a crimped SIP-16 connection?

With proper installation and use of antioxidant paste - 25–30 years. Without paste, the period is reduced to 5–10 years due to corrosion.

What is the difference between GA and AMG sleeves?

GA - aluminum sleeves for connecting aluminum to aluminum. AMG — aluminum-copper sleeves for connecting aluminum to copper (for example, when connecting to a copper cable in a panel).

Is it possible to connect SIP-16 to a copper cable without an aluminum-copper sleeve?

No! Direct contact of aluminum with copper leads to electrochemical corrosion and circuit breakage. Be sure to use GAM sleeve or branch clamp with puncture.

How to check the quality of crimping without special devices?

Visually: the sleeve should have uniform hexagonal dents without cracks. Mechanically: try turning the sleeve on the wire - it should not move. You can also lightly pull the wire - if the sleeve does not slip off, the crimping is done correctly.