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General
Tray cable, Type TC is an approved wiring method in the NEC found in article 336. It is an efficient method of installing feeders, branch circuits and control cable because multiple runs of tray cable can be installed in one cable support system (i.e. cable tray) rather than multiple conduit runs, which adds to labor and material cost.
Description
Tray cable is a factory assembly of two or more insulated conductors with or without an associated equipment ground conductor under a non-metallic jacket. For feeder and branch circuits, tray cable can be manufactured with any of the insulation types found in NEC 310.4 (A) or (B). Depending on the insulation used, tray cable will have either 600, 1000 or 2000 volt rating. Metallic shields are allowed over groups of conductors or under the outer jacket or both. Metallic sheaths or armor is not allowed under or over the non-metallic jacket, doing so would make the cable type MC cable.
Use/Locations
Type TC cable can be used for a variety of applications such as, power, lighting, control, signal circuits, class 1 circuits and non-power limited fire alarm circuits. Tray cable cannot be installed where it is subject to physical damage and must be installed in a cable tray with exceptions. Sections of the tray can have up to one foot breaks or separations without the need of adding protection to the cable in these areas.

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Background:
Color codes are used to identify conductors for point-to-point wiring and for circuit diagrams. The Insulated Cable Engineers Association outlines the color code in Standard S-73-532 in Annex E. The Standard breaks down the color code into methods of circuit identification. The most common methods used are Method 1, 3, and 4. After the Method is selected then the assembly of conductors must follow a color sequence from the tables with Table 1 and 2 being the most common.
National Electrical Code (NEC)
The NEC specifies that conductor colored white be used only as grounded conductors and that conductors colored green or green/yellow be used only as grounding conductors and that neither white nor green be used in any manner on ungrounded conductors. Tables 2 provide color sequences that do not include white or green conductors. If grounded or grounding conductors, or both, are used in the cable, they shall be colored white or green respectively, and inserted as the second or third, or both, designated conductor in the first sequence of circuit identification only. Where these conductors are required, they shall be specified.
Methods of Circuit Identification:
Method 1 - Colored Compounds
This method uses base color of insulation and uses tracers when needed, in accordance with Table 1 or 2. Base colors may be obtained by suitable color coatings applied to the insulation or jacket surface or by colored insulation or jacket compound. Tracers shall be colored stripes or bands marked on the surface of the insulation or jacket in such a manner as to afford distinctive circuit coding throughout the length of each wire. Tracers may be continuous or broken lines, such as a series of dots or dashes, and shall be applied longitudinally, annularly, spirally, or in other distinctive patterns.

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Introduction: One significant change to UL 44 (Standard for Safety for Thermoset-Insulated Wires and Cable) in the 2018 release is the addition of the 1000 Volt rating of US type designations. Now XHHW, in addition to having a 600 Volt rating, can be rated 1000 Volt. RHH and RHW cables, which had 600 V and 2000 V ratings, now can be rated 1000 Volts.

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Purpose: Withstand testing can be performed on either new or aged cables. The test should only be done if there is concern that cable damage has occurred possibly during installation or the insulation has been compromised due to heat, water or chemicals. General Testing Information • The test can be conducted with AC or DC voltages. • AC Withstand Test for field acceptance is 80% of factory test voltage. See table below. • DC Withstand Test for field acceptance is three times greater than the AC Withstand Test. See table below.

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The objective of this procedure is to provide a means of repairing gouges, tears or indents on cables that occasionally happen in the field. Thisprocedurecoversbothmediumvoltageandlowvoltage power cables and will restore the cable back to its original integrity. The purpose of the outer jacket on medium voltage cables and low voltage multi-conducor cables is to protect the underlying components from physical and environmental damage and serves no dielectric purpose. On low voltage single conductor cables, generally, the outer layer is the cables primary insulating layer. For medium voltage cables with damage beyond the outer jacket such as the copper tape shield is torn or on low voltage cables where the conductor is damaged, contact your Southwire Represen- tative. Cable jacket repairs should only be performed by qualified personnel.

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Purpose: Insulation resistance testing is a non-destructive test procedure. The test measures the insulation resistance between the phases and/or between phase and ground. It is commonly used in the industry for acceptance testing prior to energizing the cable and for maintenance testing programs. General Testing Information • For single conductor non-shielded cable on a reel, insulation resistance testing cannot be performed due to the fact that low voltage single conductors do not have a grounding conductor, shield or ground plane. • For other cable on a reel, insulation resistance testing can be performed provided the sealing caps are removed. The procedure to test these cables is outlined below. • NOTE: It is important to remove sealing caps from both ends of the cable to be tested. Residue inside the sealing cap can be conductive and lead to false readings.

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Did you know that if you run cables that connect your variable frequency drives (VFDs) to your motors you could have a significant safety risk in your plant or factory? Fear not, there is a simple solution to this potential problem. It’s a fact. Non-shielded cables emit noise. In many cases, this is not a significant prob- lem. Most of us have heard that 60 Hz hum that happens when a phone line is run too close to a standard 600 Volt power cable. It’s really nothing more than a nuisance with standard power. But the same physics behind that hum may be creating a safety issue in your facility. VFDs change standard 60 Hz power in to variable frequency power that allow us to ex- perience significant energy savings, better control of our equipment, and reduced main- tenance costs. However, like most things in life, there are trade-offs. The down-side of a drive system is that it generates lots of high frequency voltage components that can cause problems with motors, drives, and other plant equipment. These same high frequency waveform components can also cause safety issues. Let’s look at how.

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Insulation compound chemistry has come a long way in todays market. The chemistry for cross-linked polyethylene (XLPE) and ethylene propylene rubber (EPR) changed in the 1960s so modern XLPE and EPR insulations use catalysts that chemically cross-link the molecular chains yet do not corrode the conductor. Similarly, advances in semi-conducting shield compounds deliver far better stripability with bare copper conductors. Corrosion is another reason tinning is considered. Today, there are special electrical contact lubricants such as NO-OX that prevents the formations of oxide films at termination points making tinning less desirable. In conclusion, unless the power cable installation is in an environment that is continuously exposed to corrosive elements (as is the case in certain wastewater treatment facilities), copper conductor tinning is a practice that is no longer required with today’s cable compounds, corrosion lubricants and manufacturing technology. It’s an added cost that also requires longer lead times and minimum run quantities. And since it is an environmentally unfriendly process, any reduction in conductor tinning helps to make our environment better.

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Correctly sizing a VFD Cable for your drive and motor is really not difficult if you know where to look. By knowing what sections of the National Electrical Code (NEC) to ref- erence, you can correctly size cable conductor size for your system. Just follow these five simple steps to size cables for low voltage drive systems with operating voltages not greater than 575 volts. STEP ONE: Determine the minimum temperature rating of your equipment. Temperature ratings are important to know when derating the cable for the application as higher temperature ratings allow cables to handle more current. The NEC tables for ca- ble ampacity for low voltage cables have columns for 60°C, 75°C and 90°C. The column you use will be based on the minimum temperature rating of your drive terminals, your motor terminals, and your VFD Cable. Most drive terminals are rated for 75°C. All Southwire VFD Cables carry a 90°C conduc- tor temperature rating but this is not true of all VFD Cables from other manufactures. Motor terminal temperature ratings can vary from 60°C to 90°C. Each of these temperature ratings needs to be verified with the manufacturer’s datasheets or user manuals. If other equipment is being used that is in the cable’s path, like a quick disconnect, collect that devices temperature raring too. Once you have all the temperature ratings, record the minimum value.

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Southwire® Industrial Power Cable products do not have a defined shelf life. These products are composed of hard goods (metal, polymer, etc., ...) that are designed for many years of service once installed. As long as the products are not damaged during storage/handling and they are stored in a facility that protects against exposure to weather (sunlight and precipitation), there should be no degradation to the electrical and mechanical performance of the products and no reduction in service life. When storing cable the following precautions should be considered

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