Technical Guide: Mastering Low-Voltage Cable Selection
Founded in 1967, Allwire continues to develop our product line with a staff focused on our customers’ unique needs. Our reputation within the American electronics manufacturing industry is second to none. Now, in our sixth decade, our company’s philosophy remains the same: to carry on the tradition of quality, which was established all those years ago.
A Brief History of Our Company
Established in 1967 by the Hopkins family as a local distributor of wire products, the company quickly developed a reputation as a quality supplier of wire and cable. Based on years of experience in the wire and cable industry, manufacturing soon became the company’s primary focus.
Born in California – Serving Customers Across the Nation
Today, headquartered in Chowchilla, California. Allwire’s reputation as a Control Cable and CIC manufacturer is widely known, serving customers from California to Florida. Our capabilities have grown over the years with engineering and manufacturing expertise extending a variety of custom cables and HDPE conduit applications. Today, the company regularly produces shielded and non-shielded control cables up to 500 MCM in size, and HDPE conduit up to 4″ O.D shipped on 108″ reels.
Allwire completed the first phase of construction at Chowchilla, California, in February 1989. Since then, a railroad spur has been added, and two additional construction phases have been completed, bringing the total to 75,000 square feet. Administration, finance, marketing, and sales relocated their offices to the Chowchilla plant from Fresno in 2006, bringing together all company components and simplifying communications and management.
Over Half a Century of Quality Manufacturing and Customer Service
For more than 57 years, Allwire’s name has come to mean “Quality” and “Customer Service” throughout the industry—not just any quality or customer service, but high standards by a professional staff. Our philosophy, established all those years ago, remains the same: “Our customers come first.”
SOLID COPPER CONDUCTOR
| AWG | Nominal O.D. | Area Cir. Mils | Weight LBS/MFT | Feet Per Lb. | Breaking Strength | Tinned | Bare |
|---|---|---|---|---|---|---|---|
| DC Resistance ohm/MFT | |||||||
| 36 | 0.005 | 25 | 0.0757 | 12,210 | 0.7854 | 431 | 423 |
| 34 | 0.0063 | 39.7 | 0.1203 | 8,312 | 1.249 | 272 | 266 |
| 32 | 0.008 | 64 | 0.1913 | 5,227 | 1.986 | 169 | 165 |
| 30 | 0.01 | 100 | 0.3042 | 3,287 | 3.157 | 107.9 | 106 |
| 28 | 0.0126 | 159 | 0.4837 | 2,067 | 5.02 | 67.8 | 66.6 |
| 26 | 0.016 | 253 | 0.77 | 1,298 | 7.983 | 44.5 | 41.8 |
| 24 | 0.0201 | 404 | 1.22 | 819 | 12.69 | 26.7 | 26.2 |
| 22 | 0.025 | 643 | 1.94 | 515 | 19.43 | 16.8 | 16.4 |
| 20 | 0.032 | 1,020 | 3.1 | 322 | 30.89 | 10.5 | 10.4 |
| 18 | 0.0403 | 1,620 | 4.92 | 203 | 49.12 | 6.77 | 6.5 |
| 16 | 0.0508 | 2,580 | 7.81 | 128 | 78.1 | 2.2 | 4.1 |
| 14 | 0.0641 | 4,110 | 12.4 | 80 | 124.2 | 2.68 | 2.6 |
| 12 | 0.0808 | 6,530 | 19.8 | 50 | 197.5 | 1.65 | 1.62 |
| 10 | 0.102 | 10,380 | 31.4 | 31 | 314 | 1.04 | 1.02 |
| 8 | 0.1285 | 16,510 | 49 | 20 | 479 | 0.65 | 0.64 |
| 6 | 0.162 | 26,240 | 79.4 | 12.5 | 763 | 0.41 | 0.395 |
| 4 | 0.204 | 41,740 | 126 | 7.9 | 0.258 | ||
| 2 | 0.292 | 66,407 | 205 | 4.8 | 0.16 | ||
| 1 | 0.332 | 83,771 | 266 | 3.7 | 0.127 | ||
STRANDED COPPER CONDUCTOR
| AWG | Stranding | Nominal O.D. | O.D. Single End | Weight LBS/MFT | Feet Per LB. | Area Cir. Mils | Tinned | Bare |
|---|---|---|---|---|---|---|---|---|
| DC Resistance ohm/MFT | ||||||||
| 30 | 7/38 | 0.012 | 0.00397 | 0.21 | 4,762 | 112 | 106 | 92.6 |
| 28 | 7/34 | 0.015 | 0.005 | 0.48 | 2,083 | 175 | 67.5 | 59.3 |
| 26 | 7/36 | 0.019 | 0.0063 | 0.87 | 1,149 | 278 | 42.5 | 37.3 |
| 26 | 10/36 | 0.019 | 0.005 | 0.78 | 1,282 | 250 | 47.3 | 40.4 |
| 26 | 19/38 | 0.021 | 0.00397 | 0.97 | 1,031 | 304 | 38.9 | 34.1 |
| 24 | 7/32 | 0.024 | 0.008 | 1.22 | 819 | 448 | 25.7 | 23.1 |
| 24 | 19/36 | 0.025 | 0.005 | 1.48 | 675 | 475 | 24.9 | 21.8 |
| 22 | 7/30 | 0.031 | 0.01 | 2.19 | 456 | 700 | 16.6 | 14.8 |
| 22 | 19/34 | 0.032 | 0.0063 | 2.35 | 425 | 754 | 15.5 | 13.8 |
| 20 | 7/28 | 0.038 | 0.0126 | 3.49 | 286 | 1,111 | 10.3 | 9.33 |
| 20 | 10/30 | 0.036 | 0.01 | 3.14 | 318 | 1,000 | 11.4 | 10.4 |
| 20 | 19/32 | 0.04 | 0.008 | 3.84 | 260 | 1,216 | 9.48 | 8.53 |
| 18 | 7/28 | 0.048 | 0.0126 | 5.55 | 180 | 1,770 | 6.45 | 5.86 |
| 18 | 16/30 | 0.046 | 0.01 | 5.01 | 199 | 1,600 | 7.15 | 6.48 |
| 18 | 19/30 | 0.05 | 0.01 | 5.95 | 168 | 1,900 | 6.1 | 5.46 |
| 18 | 41/34 | 0.047 | 0.0063 | 5.09 | 196 | 1,627 | 7.08 | 6.6 |
| 16 | 7/.0192 | 0.058 | 0.0192 | 7.9 | 126 | 2,581 | 4.16 | |
| 16 | 19/29 | 0.057 | 7.52 | 133 | 2,426 | 4.82 | 4.27 | |
| 16 | 26/30 | 0.06 | 0.01 | 8.15 | 122 | 2,600 | 4.39 | 4.13 |
| 16 | 65/34 | 0.06 | 0.0063 | 7.98 | 125 | 2,580 | 4.47 | 4.16 |
| 14 | 7/.0242 | 0.073 | 0.0242 | 12.7 | 77 | 4,100 | 2.61 | |
| 14 | 19/27 | 0.071 | 12.1 | 82 | 3,831 | 3.05 | 2.71 | |
| 14 | 41/30 | 0.069 | 0.01 | 12.9 | 77 | 4,100 | 2.81 | 2.53 |
| 12 | 7/.0305 | 0.092 | 0.0305 | 20.2 | 49 | 6,512 | 1.64 | |
| 12 | 19/25 | 0.09 | 19.4 | 51 | 6,088 | 1.87 | 1.7 | |
| 12 | 65/30 | 0.091 | 0.01 | 20.8 | 48 | 6,500 | 1.82 | 1.6 |
| 10 | 7/.0385 | 0.116 | 0.385 | 32 | 31 | 10,376 | 1 | |
| 10 | 19/.0234 | 0.117 | 0.0234 | 32 | 31 | 10,404 | 0.98 | |
| 10 | 37/.0169 | 0.112 | 0.0169 | 29.2 | 34 | 9,361 | 1.25 | |
| 10 | 105/30 | 0.13 | 0.01 | 33.1 | 30 | 10,500 | 1.1 | 0.99 |
N.E.C. SUBSTITUTIONS
| Table 725 - 61 Article 725 N.E.C | ||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| TYPE MAY BE SUBSTITUTED BY CODES CHECKED BELOW | ||||||||||||||||||
| TYPE | MPP | CMP | FPLP | CL3P | CL2P | MPR | CMP | FDLR | CL3R | CL2R | MP | CM | FPL | CL3 | CL2 | CMX | CL3X | PLTC |
| CL3P | YES | YES | YES | |||||||||||||||
| CL2P | YES | YES | YES | YES | ||||||||||||||
| CL3R | YES | YES | YES | YES | YES | YES | YES | |||||||||||
| CL2R | YES | YES | YES | YES | YES | YES | YES | YES | YES | |||||||||
| CL3 | YES | YES | YES | YES | YES | YES | YES | YES | YES | YES | YES | YES | ||||||
| CL2 | YES | YES | YES | YES | YES | YES | YES | YES | YES | YES | YES | YES | YES | YES | ||||
| CL3X | YES | YES | YES | YES | YES | YES | YES | YES | YES | YES | YES | YES | YES | YES | YES | |||
| CL2X | YES | YES | YES | YES | YES | YES | YES | YES | YES | YES | YES | YES | YES | YES | YES | YES | YES | YES |
| Table 760 - 61 Article 760 N.E.C. | ||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| TYPE MAY BE SUBSTITUTED BY CODES CHECKED BELOW | ||||||||||||||||||
| TYPE | MPP | CMP | FPLP | CL3P | CL2P | MPR | CMP | FDLR | CL3R | CL2R | MP | CM | FPL | CL3 | CL2 | CMX | CL3X | PLTC |
| CL3P | YES | YES | YES | |||||||||||||||
| CL2P | YES | YES | YES | YES | YES | YES | ||||||||||||
| CL3R | YES | YES | YES | YES | YES | YES | YES | YES | YES | YES | YES | YES | ||||||
| Table 800 - 53 Article 800 N.E.C. | ||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| TYPE MAY BE SUBSTITUTED BY CODES CHECKED BELOW | ||||||||||||||||||
| TYPE | MPP | CMP | FPLP | CL3P | CL2P | MPR | CMP | FDLR | CL3R | CL2R | MP | CM | FPL | CL3 | CL2 | CMX | CL3X | PLTC |
| CL3P | ||||||||||||||||||
| CL2P | YES | |||||||||||||||||
| CL3R | YES | |||||||||||||||||
| CL3R | YES | YES | YES | |||||||||||||||
| CL3R | YES | YES | ||||||||||||||||
| Cl3R | YES | YES | YES | YES | YES | |||||||||||||
| CL3R | YES | YES | YES | YES | YES | YES | ||||||||||||
N.E.C. FLAME TESTS
| UL TYPE | Plenum Cable – UL 910 (NPFA 262) | |||
|---|---|---|---|---|
| MPP CMP FPLP CL3P CL2P CATVP | The UL 910 (or NFPA 262) test for plenum cable has been in use since 1978. It is a modified version of the Steiner Tunnel test, which has been used to test building materials for over fifty years. Cables are mounted horizontally in a 25-foot-long tunnel with a 320,000 BTU/hr. gas flame at one end and air flowing through the tunnel at 240 ft./min. Both flame spread and smoke generation are measured. It is the only test that measures smoke generation. UL 910 is the most difficult flammability test for low-voltage cable. All plenum must pass this test. Any cable which passes this test is automatically assumed to pass any of the other three new tests, which are less severe and have no smoke generation requirements. |
|||
| UL TYPE | Riser Cable – UL 1666 | |||
| MPR CMR FPLR CL3R CL2R CATVR | The first of the three new flammability tests is for riser cables and is designed UL 1666. This is a modification of the old UL 1581 flame test and involves a 12-foot Vertical Open Tray with a 495,000 BTU.hr. gas flame applied at the bottom for thirty minutes. Note that riser cables are used in special areas that connect one floor to another in commercial buildings and penetrate fire-rated walls and floors. | |||
| UL TYPE | General Building Wiring – UL 1581 (Vertical Tray Flame Test) | |||
| MP CM FPL CL3 CL2 CATV | The second new flammability test is for general building wire used in commercial buildings. This is wire used in areas other than plenums and risers. This test is less severe than the riser cable test and consists of a vertical 8-foot open tray subjected to a 70,000 BTU/hr. flame for twenty minutes. It is similar to the UL 1581 and IEEE 383 tests. | |||
| UL TYPE | Restricted Use – VW-1 | |||
| CMX CL3X CL2X CATVX | The third new flammability test is for residential wire as used in one—and two-family dwellings. It is a laboratory test using a Bunsen burner and a single vertical wire and has the least critical requirements of the four flammability tests. Wire passing this test may be used in conduits in nonresidential buildings, and exposed lengths up to ten feet are permitted in non-concealed spaces only. | |||
LEVEL 1-5 DEFINITIONS
| Level | Definitions |
|---|---|
| Level 3 | Level 3 cable complies with the transmission requirements in the Electronic Industries Association/Telecommunication Industry Association EIA/TIA 568 Commercial Building Telecommunications Wiring Standard for Horizontal Unshielded Twisted -Pair (UTP) Cable and with the requirements for Category 3 cable in the EIA/TIS Technical Systems Bulletin (TSB-36) It is intended for high-speed LAN applications up to and including 16 MBPS. In addition to Level 1 and 2 applications, this cable can also be used for 10 Base-T, OPEN DEConnect, 3-COM, PROTEON, 4 MBPS token ring, and CHIPCOM systems. |
| Level 4 | Level 4 cable complies with the proposed National Electrical Manufacturers Association (NEMA) Standard for Low-Loss Premises Telecommunications Cable requirements. Level 4 requirements are the same as Category 4 requirements of the Electronics Industry Association/Telecommunication Industry Association (EIA/TIA) Technical Systems Bulletin TSB-36. This cable is intended for high-speed LAN applications up to and including 20 MBPS. |
| Level 5 | Level 5 cable complies with the proposed National Electrical Manufacturers Association (NEMA) Standard for Low-Loss Premises Telecommunications Cable requirements. Level 5 requirements are the same as Category 5 requirements of the Electronics Industry Association/Telecommunication Industry Association (EIA/TIA) Technical System Bulletin TSB-36. This cable is intended for high-speed LAN applications up to and including 100 MBPS. |
GLOSSARY OF TERMS
| Terms | Definitions |
|---|---|
| Attenuation | Power loss in an electrical system. |
| Audio Frequency | The range of frequencies audible to the human ear. Generally considered as 20-20,000 Hz. |
| Capacitance | That Property in a system of conductors and dielectrically separated charges whenever a difference in potential exits between the conductors. |
| Current Carrying Capacity | The maximum current an insulated conductor can safely carry without exceeding its insulation and jacket temperature limitations. |
| Decibel (dB) | A standard unit for expressing transmission gain or loss and relative power levels. |
| Dielectric | Any insulating medium used to separate two conductors. |
| Dielectric Constant | The ratio of the capacitance of an insulated wire with that of the same wire uninsulated in air. |
| Drain Wire | An uninsulated wire added during manufacturing adjacent to the shield to facilitate shield grounding connections. |
| Elongation | The fractional increase in length of a materiel stressed in tension. |
| Fared | The standard unit of capacitance. |
| Flame Resistance | The ability of material not to propagate flame once a heat source is applied and then removed. |
| Flat Cable | A paralled conductor cable in which conductors are arranged side-by-side with an integral insulation/jacket. |
| Frequency | The number of cycles completed by an alternating current in one second. |
| Hertz | Standard unit of frequency equal to one cycle per second. |
| Impedance | The total opposition that a circuit offers to the flow of alternating current at a particular frequency. It is a combination of resistance (R) and reactance (X), measured in ohms. |
| Insulation Resistance | AN insulation’s ability to resist the flow of current through it, usually expressed in megohm-feet. |
| Jacket | An outer covering, usually non-metallic, 1 mainly used for Any cable consisting of two or more conductors. |
| Capacitance | The capacitance between two conductors when all other conductors, including the shield, are short-circuited to ground. |
| Ohm | The standard unit of electrical resistance. |
| Pair | Two wires twisted together to form a single circuit. |
| Plenum | The air return path of a central air handling system, either ductwork or open space. |
| Plenum Cable | Cable approved by Underwriters Laboratories for installation in plenums without needing conduit. |
| Primary Insulation | The first layer of non-conductive material applied over a conductor whose prime function is to act as electrical insulation. |
| Rated Temperature | The maximum temperature at which an electric component can operate for extended periods without loss of its basic properties. |