This is a general purpose guide to select hook-up wire for internal device wiring to connect to a circuit board you may be designing.

NOTICE: This information is provided as a basic reference on the assumption that you are appropriately trained in designing electrical equipment. If you are not certain, please consult an electrician or electrical engineer.

CAUTION: If you are using the minimum wire gauge or trace width for your maximum (worst case) current requirement, please be aware that your wires will get very hot, especially inside an enclosure with no air circulation.

The table follows the explanation of the columns below.

AWG is the American Wire Gauge standard. Number 18 AWG is used for wiring household devices and appliances up to 1800W.

Imax (A) is the maximum current in amps for the given wire gauge for use in a device or appliance.

Trace (mil) is the equivalent trace width (in 1/1000 inch) to the given wire gauge. These widths apply to standard 1/2oz copper. You should maintain the same conductor cross section when a wire enters a PCB.

Hole (mil) is the minimum recommended pad or via through-hole diameter for inserting the given wire gauge through a PCB. It is not recommended to solder wire surface-mount unless you don’t mind the traces pulling off the board.

TR-64 and TEW are Canadian (CSA) conventions for insulation material used in wiring. Both of these are fire retardant PVC plastic, but are subject to melting and cutting. There are many other kinds of insulation, these are just the most commonly used in the electronic industry.

TR-64 = 90°C, 300V (single phase), equivalent to UL Style 1007 or 1581 or 1569

TEW = 105°C, 600V (multi-phase), equivalent to UL Style 1015

#28, #30, or #32 may be wire wrap wire, often used for modifications (wire jumpers) to PCB assemblies. This type of wire is typically only rated for 150V while the insulation is usually some Teflon variant highly resistant to heat (200°C) and cutting. It is not expected to go off-board.

H/S TR64 is the size of heatshrink to use on TR64 wire, assuming 2:1 such as FIT221. Sizes in parentheses may be especially tight or loose, but passable in a pinch.

H/S TEW is the size of heatshrink to use on TEW wire, same assumptions as TR64.

You should be careful to specify stranded wire if it will be subjected to bending because it is far less likely to break. Solid wire is stiffer and tends to hold its shape. Wire wrap wire is solid.

You should be careful to specify pre-tinned wire (not bare copper) if you expect it to be soldered. We have a solder pot and can tin wires as an extra step in the manufacturing process.

AWG Imax (A) Trace (mil) Hole (mil) H/S TR64 H/S TEW
6 101 1178 200 (3/8) 1/2
8 73 747 150 (1/4) 3/8
10 55 467 125 (3/16) 1/4 (3/16) 1/4
12 41 293 100 (1/8) 3/16 (1/4) (3/16) 1/4
14 32 184 75 (1/8) 3/16 (3/16) 1/4
16 22 116 60 (3/32) 1/8 (1/8) 3/16 (1/4)
18 16 73 48 (3/32) 1/8 (1/8) 3/16 (1/4)
20 11 46 36 (3/23) 1/8
22 7 29 32 (1/16) 3/32 (1/8)
24 3.5 18 24 (1/16) 3/32
26 2.2 11 20 (1/16) 3/32
28 1.4 7 16 1/16 (3/32)
30 0.86 4 12 1/16
32 0.53 3 10


Wire Selection for PCB Design

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