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Wire and Cable Blog

Category: tray cable

Types of Tray Cable Explained

The term “tray cable” was developed through its installation in cable tray. Each type of insulation is engineered to be able to withstand some type of environmental condition that could possibly damage the copper underneath it. In cable tray, insulation would come in contact with moisture, oils and solvents and if it’s not protective enough to withstand those things the copper could be affected.

The first two things to determine about your tray cable will be the voltage and the shielding. There is a 300 volt version called PLTC (Power Limited Tray Cable) and a 600 volt “tray cable” for applications requiring more power. There are three versions of shielding that are offered including unshielded, shielded and individually shielded.

Tray Cable Shielding

Shielded Tray CableAn unshielded tray cable is the cheapest and most basic version you can get if your application doesn’t need to block EMI (Electromechanical Interference). When two cables run next to each other in tray or duct there can be a certain amount of interference which is blocked with a shield over the conductors. An aluminum foil polyester shield wraps around all of the conductors to limit the amount of EMI. To picture it in your mind, imagine a glowing circumference pulsating around each of the cables. When they connect there’s “interference” so the shielding shrinks that circumference to limit the amount of interference.

Shielded Tray CableAn individually shielded tray cable has a shield around each pair of wires inside the cable. So a “3 pair” cable has an individual shield around each pair and an overall shield wrapping around all of the conductors together. This is needed when each pair can interfere with each other. The shield will limit the EMI between each set of two wires so that there is a clean signal passing through.

Flexible Tray Cables

Once you decide the voltage and the shielding for your tray cable you will just need to figure out the AWG (American Wire Gauge) and the amount of copper conductors. The flexibility remains the same throughout most tray cables because the installation types are nearly all the same. When a cable is being snaked through duct, or pushed through cable tray, added flexibility would only hurt the process. Therefore, most tray cables come with stiff copper strands to keep a firm hold during the installation in tray and duct.

There are plenty of flexible electronic cables available that are similar to tray cables that can be used if your installation is a bit different than the standard. So, make sure that the insulation with withstand everything that the cable will be exposed to and include the option of added flexibility to your cable. It will bend easier and wrap around corners easier but it will not be the best option for a cable installed in conduit or duct.

Written by: Chris Bell

Attributes of Unshielded PLTC Tray Cable

Unshielded PLTC tray cable has a unique construction that makes it distinct from the rest of the types of wires and cables. The construction is defined by the cable’s conductor, insulation, and jacket. The materials of construction used for all unshielded power limited tray cable are 0.012 inches wall of PVC insulation that can withstand a maximum temperature of 105 degree Celsius. The black PVC jacket which is considered to be resistant to fire has a wall that measure up to 0.032 inches.

The conductor of the aforementioned tray cable is a tinned copper as per ASTM B-33 that is fully annealed. The insulation is top of the line in terms of quality made of PVC. The insulation is color coded which makes use of the following codes: black (1), red (2), white (3), and green (4). To complete the construction, is the jacket which is usually gray in color and made of PVC. It is appropriate for temperature range of negative 20 degrees Celsius up to 105 degrees Celsius.

The usual application of unshielded power limited tray cables is more or less similar to that of the shielded counterpart. The unshielded power limited tray cable is an economic and cost efficient alternative for shielded tray cable which is a bit more costly. The following are the usual applications that both shielded and unshielded tray cables are used: installation of cable trays, circuits with limited power applications, system and alarms against thieves, automated valve control systems, applications with suggested voltage rating of 300 volts, systems for irrigation, systems for intercom, and machines for industrial and business applications.

In general, the unshielded power limited tray cables are known for the following specific features: resistance to sunlight due to the PVC jacket that covers it, capability to withstand extremely hot and extremely cold conditions, and highly sturdy, tough and long lasting.

Unshielded PLTC tray cable has a controlled level of voltage that can be contained, usually up to a voltage of 300 volts, and option of redirecting the electricity by coursing it through two to three conductors per cable. The tray cable comes with insulation that is 22 AWG that comes across the 12 AWG covered completely by the gray PVC jacket. It can be used outdoors without the fear that sunlight, moisture, and weather conditions will be interfering in its basic function. Despite the fact that it is unshielded, it comes in with a jacket that provides the basic protection.

The upper limit temperature that the PLTC can bear is at around 105 degree Celsius or above the boiling point. PLTC are UL and CSA Approved. They also have a paired color coding approach: black and red; the PLTC have color coding for trios as well: black, red, and white.

The unshielded PLTC tray cables come from different manufacturers that offer several variations which include unshielded, multi-conductor, multi-paired, Alpha 45125, or those will individually protected pairs. The usual applications are circuits that do not require a long wiring system. Compliant with significant standard states, each power limited tray cables are delivered expediently marked with corresponding instructions for the appropriate installation of the tray cable for an array of applications. 

WesBell Electronics Inc
(800) 334-8400

Shielded and Unshielded Tray Cable Information

Tray cable has a different meaning to a lot of people and each person seems to think that phrase describes exactly what they need, but more information is actually needed. There are many applications that require different types of tray cable and each will have their own specifications that are needed to extend the cable life as long as possible.

The main difference is shielded or unshielded because paying for a shield when you don’t need one is a waste of money. However, not getting a shield when you need one will cause many problems. Imagine a force field, or ring of vibration, that hovers outside of a cable due to the electrical current running through it. That’s called EMI which is “electromagnetic interference” that could interfere with other cables EMI or other equipment.

The shield over the copper conductors of a tray cable minimizes the EMI that can get outside the cable and also blocks other cables EMI from interferring with it. An unshielded tray cable can be used when it can’t interfere with any other cables or equipment.

For applications with very high EMI there is also a multipair tray cable that has sets of two twisted wires and a optional individual shield over each pair in the cable. The twist limits the EMI and the added shield over each pair lowers the EMI quite a bit more than a standard aluminum overall shield.

Voltage is the next difference to discuss because there are 300 and 600 volt tray cables available. The 300 volt PLTC (Power Limited Tray Cable) is commonly used indoors, outdoors and in conduit. The 600 volt tray cable has a larger outer diameter and it’s used outdoors, in conduit and directly underground.

Please call if you’re looking for any type of tray cable or if you have any questions or comments about our website. We work hard on the website to not only offer products for sale, but to inform buyers and users of why they’re buying a particular product we have. By getting into conversation about the application we have the ability to help them save money because they may not have needed everything they thought they did.

WesBell Electronics Inc
(800) 334-8400

Power Limited Tray Cable – 300 Volt Shielded and Unshielded

Power limited tray cable is also known as PLTC electronic cable that comes in 300 volts rather than the 600 volt power cable. The common variations are unshielded, shielded, individually shielded, multiconductor and multi pair which each have different uses in the electronic field.

We offer the 2 and 3 conductor unshielded (and many others on our website) which come in guage sizes 22 through 12. The stranding in each conductor is similar to PVC hook up wire with each having 30 awg tinned copper strands. These 2 and 3 conductor PLTC cables also have an overall shielded version in the same guage options.

Each of the 300 volt tray cables are UL and CSA approved along with a few other NEC code approvals. They’re also sunlight resistant in order to allow the cable to be used outdoors and in conduit. It’s very common to see PLTC electronic cables used indoors as well.

The overall shield offers one aluminum polyester shield over all of the conductors in the cable while the individual shield offers a separate foil shield over each pair in the cable. The indivivdually shielded cables also offer a stranded tinned copper drain wire.

The 600 volt tray cables are not known as PLTC cable because the “PL” stands for power limited. There isn’t an individually shielded option or a multipair option available in the 600 volt cables. However the 600 volt tray cables are manufactured for underground use as a direct burial cable. Being able to install a cable directly underground can save a lot of time compared to installing conduit and running the wires afterwards.

The standard color code for tray cable is black, red and white. The 2 and 3 conductors cables in the PLTC version are offered with a black and red or a black, red and white insulated wire. The multipair cables offer black and red pairs that are each numbered to distinguish from the other pairs in the cable.

We also offer the 600 volt THHN PVC tray cable that comes in much larger awg sizes for bigger applications. They start with an 8 awg and get as large as 500 mcm in 3 or 4 conductors with an additional ground wire. This type of tray cable is also an underground cable giving it a universal use indoors, outdoors, in conduit or directly in the Earth. They come with all black conductors and a bare uninsulated ground wire. The black conductors are numbered for identification.

Please let us know if you’re looking for any type of PLTC or 600 volt tray cable shielded or unshielded. We’ll be able to help you find what you’re looking for and possibly help you find a cheaper way to get the job done.

WesBell Electronics Inc
(800) 334-8400

Tray Cable – Underground Multi-Conductor Electrical Wire

Tray cable has become a very big seller over the past year for WesBell Electronics. We started selling all types of electrical wire over 5 years ago to compliment our already booming electronic line. Tray cable has been a very easy sell for many reasons in the electrical industry.

Our type TC-ER tray cable is manufactured with THHN wire conductors and a PVC water tight jacket which makes it available for direct burial in the ground. It’s round with a black jacket and all black conductors that are numbered for easy installation. It ranges in awg sizes from 18 to 750 mcm with up to 4 conductors and a ground wire.

The reason it’s such an easy sell is that it has all the bells and whistles with out the outragous pricing. Copper still weighs heavily on the price because it’s so high right now but other cables manufctured for the same undergound use have a higher expense.

Type MC cable is slightly cheaper because it can only be used in conduit. If you want an MC cable that can be direct buried you’ll need the additional PVC jacket over the metal clad armour. That makes for a very expensive cable but it can also be used in concrete which tray cable cannot.

Many of our customers call and want to use Romex® for their application. Then they say it’s only going outside for a few feet so it should be fine for this situation. Well that’s not true. Romex® doesn’t have the protection that UFB cable and tray cable have because it’s only made to be used for indoor applications. That’s why it’s cheaper and that’s probably why they want to is it over the more expensive cable, but getting tray cable first is better than replacing the Romex® later.

WesBell Electronics Inc
(800) 334-8400