What is the typical diameter of the DC line?

Complete description of DC power cable diameter (divided into two categories: copper core conductor diameter and overall outer diameter of the finished cable, suitable for video surveillance DC cables)

The diameter of DC cables has two key parameters: one is the diameter of the single copper wire inside (determining the conductivity, corresponding to AWG wire gauge); the other is the overall outer diameter of the 2-core DC power cable with PVC sheath after completion (reference for engineering wiring, conduit installation, and connector compatibility). The mainstream 5.5*2.1 DC extension cable specifications for video equipment are as follows.

1. Diameter of a single copper conductor (corresponding to AWG wire gauge)
The inner part of the DC cable is a multi-strand twisted copper wire. The industry standard AWG refers to the diameter of a single copper wire:
1. 1.24AWG (0.2 square): Single copper wire diameter 0.511mm, mostly used for extremely short small household appliances and monitoring, rarely used in surveillance
2. 2.22AWG (0.3 square, standard for home cameras): Single copper wire 0.643mm, suitable for indoor 5-meter small cameras
3. 3.20AWG (0.5 square, conventional infrared gun cameras): Single copper wire 0.812mm, mainstream specification for 10-meter indoor monitoring
4. 4.18AWG (0.75 square, high-speed ball / long-distance wiring): Single copper wire 1.024mm, dedicated for large current pan-tilt units and outdoor long lines
II. 2. Overall outer diameter of the DC finished cable (the overall thickness of the entire cable, commonly used in engineering as OD outer diameter)
The standard outer diameter of the 5521/5525 DC dual-core cable (two insulated cores wrapped with PVC sheath, red + black) available on the market:
1.22AWG/0.3 square DC wire: Finished outer diameter OD 4.0mm (the thinnest model, home short extension cord)
OD 4.0 thin model 22AWG DC cable
2.20AWG/0.5 square DC wire: Finished outer diameter OD 4.8–5.2mm, standard indoor monitoring standard wire
0.5 square standard DC wire
3.18AWG/0.75 square thickened DC cable: Finished outer diameter OD 5.8–6.5mm, thickened model for large current dome cameras
0.75 square thickened DC wire
4. Dual shield DC cable (with aluminum foil + copper mesh for anti-interference, live streaming / industrial cameras): Outer diameter increased by about 1mm, 0.5 square shielded model OD ≈ 6.0mm, 0.75 square shielded model OD ≈ 7.2mm
III. Reference for DC cable Diameter in Special Scenarios
1. Single-core bare wire (with no extension sheath): Only two independent insulated cores are visible. The outer diameter of a single core insulation is 1.6–2.2mm. The total width of two cores placed side by side without an outer sheath is 3.5–4.5mm.
2. Outdoor double-layer TPU waterproof DC cable: The outer diameter is larger than that of ordinary PVC by 0.3–0.6mm under the same core specification, and it is more resistant to aging and harder.
3. Multi-split DC wire bundle (one-to-two / one-to-four): The outer diameter of the main line increases with the increase of branches. For a one-to-four bundle, the outer diameter of the main line can reach 7–9mm when squared.
IV. Key Points for Selection and Wiring Differentiation
1. Determine if the wire diameter is falsely labeled by observing the outer diameter: If the nominal 22AWG wire has an outer diameter less than 3.5mm, or the nominal 18AWG wire has an outer diameter smaller than 5.5mm, it is likely a copper-clad aluminum wire or a thin wire with a false label. Long-distance monitoring is prone to voltage drop and screen failure.
2. Reference for conduit wiring: PVC20 conduit can accommodate a maximum of 3 wires with an OD of 4.0mm; for thickened 0.75 square OD6.0mm wires, the maximum number is 2, to avoid cracking the sheath and short circuit.
3. Connector compatibility: DC injection molded connectors have internal through holes that are compatible with wires with an outer diameter of ≤6.8mm. For wires larger than 7mm, a thickened shielded wire requires a larger hole waterproof DC connector; otherwise, the wire cannot be inserted for injection molding.
Summary (Most Common Diameter Speed Recording for Video Surveillance)
Small indoor cameras for home use, short distance: 22AWG, finished outer diameter 4.0mm
Regular infrared gun cameras within 10 meters for wiring: 20AWG, finished outer diameter 5.0mm
Outdoor pan-tilt units, lines over 15 meters: 18AWG, finished outer diameter 6.0mm
Live streaming / industrial cameras with anti-interference shielding: same specification outer diameter + 1mm