Kable specjalistyczne

LV (Low Voltage) cables operate at voltages of 1.1kV and below, and are generally used to wire buildings and supply electricity. MV (Medium Voltage) cables operate at voltages between 1kV and 35kV, and are typically used in distribution systems of electric utilities. HV (High Voltage) cables operate at voltages greater than 35kV, and are used for the transmission of electricity over long distances; they require specific insulation and design for improved performance under varying degrees of electrical stress.

A low-voltage power cable is composed of copper or tin plated copper (from 0.50 mm² to 300 mm²) as electrolytic grade conductors, core insulation made from either PVC, XLPE, or LSZH materials, a screen of either aluminium foil or mesh braid coverings used on the shielded variants, both the inner & outer sheaths protect the core from environmental damage; also available G.I. armour (metal-woven covering) for additional mechanical and impact resistance for difficult installations.

The various types that Tempsens uses include PVC (Polyvinyl Chloride) for standard installations, XLPE (Cross-Linked Polyethylene) to withstand higher heat exposure (up to 90°C), HR PVC (Heat Resistant PVC), LSZH (Low Smoke and Zero Halogen) polymers for fire safety, FR PVC and FRLS PVC, which are flame retardant, along with PE (Polyethylene) or XLPO are used for some extreme applications that comply with IS & IEC Standards.

High temperature cables utilize select types of insulation made from materials including PTFE, fiberglass, ceramics, silicone rubber, or alumina fibers.

The operating temperature ranges for the various types of insulation are: alumina fibers can handle up to 1200°C; ceramic fibers can handle up to 800°C; fiberglass can handle up to 550°C; polyimides can handle about 310°C; PTFE and PFA cables can handle up to about 260°C; and silicone rubber has a maximum operating temperature of about 180°C.

The conductor materials for high temperature cables are selected from among annealed bare copper, tinned copper, silver plated copper, nickel plated copper, pure nickel, and NPC 27% alloy based on the temperature and performance of the application.

Operating temperature, voltage grade, conductor size, environmental factors, chemical exposure, degree of flexibility required and relevant standards must all be taken into consideration when selecting a high temperature cable. Refer to the manufacturer’s specifications for assistance in making the best selection.

Heat resistant cables should be chosen based on maximum operating temperature, voltage requirement, conductor size based on current load and environmental exposure (chemicals).

A heat-resistant cable can endure continuous high-temperature service (between 200°C – 800°C) whereas Fire Resistant Cables keep circuit integrity during a fire at “normal” temperatures.

Tempsens cables are designed for continuous use and have a service life of more than 20+ years when installed correctly and within the rated parameters provided by IS 8130.

The flexibility depends on the type of insulation – the silicone and FEP have very high levels of flexibility, while the fiberglass and ceramic fiber will offer average flexibility based on the requirements of the application.

A signal cable is an electrical cable used to carry low-voltage signals between various types of industrial instrumentation systems (e.g., sensors, transmitters, controllers, and monitoring devices), and assures the quality of the data being transmitted by minimizing the effects of electromagnetic interference.

There are many different kinds of Signal Cables that come in two different styles: Armoured vs Unarmoured, screened vs unscreened, Pair vs Triad Configuration, Fire Resistant and LSZH Cables, F Type Cables (individual and overall screening), G Type Cables (overall screening) and Multi Pair Cables (from 1 Pair to 48 Pairs).

The testing of signal cables involves several different types of testing that include insulation resistance testing, conductor continuity/continuity testing, mutual capacitance (CC), ratio (R/L), and effectiveness of screening. Some aspects of professional testing include dielectric/high voltage testing, conductor resistance measurement at 20 degrees C. The amount of screening coverage can be verified and tested in NABL accredited laboratories.

Typical RTD cabling is made of copper conductors with insulation made from materials that vary based on operating temperature (e.g., PVC is used for most applications up to 105°C, PTFE or FEP cable for temperatures up to 260°C, and insulated with fiberglass for severe environments up to 600°C).

Triad cable for RTD applications has three cores twisted together, minimizing electromagnetic interference and maintaining balanced electrical characteristics between the three-wire configuration. This is necessary to balance lead wire resistance for measurement accuracy.

The RTD cable length limitation can be different depending on the wire size used, and the wiring configuration for the measurement circuit. Typically, the maximum distance for a standard installation would be around 300 meters when utilizing 20 – 22 AWG conductors in 3-wire configuration. For a 4-wire RTD connection the distance can be increased to 600 meters with no loss of accuracy.

FEP cable insulation has great chemical resistance, has a continuous operating range from -65°C to +200°C, retains excellent dielectric properties throughout its operating range, and is far more moisture resistant than standard polymer insulations.

FEP insulated cable provides almost identical chemical and thermal resistance properties of a PTFE insulated cable but is easier to process when extruded with conventional processes providing a more consistent wall thickness while also having enhanced mechanical properties at a much lower cost.

FEP cable can be installed as continuous operating at -65°C to +200°C, with the possibility for short excursions to 260°C. FEP cable is suitable for most industrial RTD applications – with the exception of the highest furnace and combustion monitoring applications.

PVC insulated cable will operate reliably from -40°C to +105°C for standard formulations of PVC insulated cable. For heat-resistant PVC compounds, the continuous operating temperature can be extended to 120°C for short durations. This temperature range is suitable for most ambient and moderate temperature RTD installations.

XLPE is cross-linked polyethylene insulated cables which provide greater temperature capability (up to 150°C continuous) than PVC insulated options and greatly improve aging resistance, but PVC insulated will be more cost-effective as a general use under temperature of 105°C.

Fiberglass insulated cable provides excellent abuse resistance with its woven glass fiber construction. Fiberglass insulated cables can provide resistance to mechanical stress, flexing, and contact with surfaces that would have damaged polymer insulations. This feature allows it to be used for furnace applications and in industrial environments with extreme temperature applications.

The selection of an MI heating cable depends on many parameters, which include the operating temperature, required heat output, available voltage, compatibility with the sheath material, and hazardous area classification. Tempsens’ engineers will analyse these parameters and help you choose the best specifications.

Use of an infrared thermometer to inspect the cable condition and occasional insulation resistance testing is usually adequate for MI heating cable because of the robust design and sealed construction.

Your MI cable will be installed directly on the surface using recommended mounting methods, covered with thermal insulation, and terminated using the special termination kits connecting the MI cable to the power supplies requiring temperature controls.

MC Cable is polymer-insulated and allows for electrical distribution; MI cable is a mineral-insulated heating cable, allowing installation in extreme temperature environments.

MI cables can withstand extreme temperatures, up to 1000°C; the cable is completely moisture proof, has better mechanical strength, has a small outer diameter, which allows for better heat distribution, and can be utilised in hazardous locations.

Fire-retardant cables resist initial ignition and slow the spread of flames. Fire-resistant cables are designed to stay functional for limited time periods during a fire event. Fire survival cables are designed to ensure full circuit integrity at temperatures exceeding 750°C for 30-180 minutes, thereby keeping essential emergency safety systems operational throughout and subsequent to varying emergency fire events.

Installation must account for minimum bending radius (6-8 times cable diameter), use of fire resistant/cable retention fixings, adequate segregation away from other cables, fire rated terminations with cable duration rating, and qualified installation per BS 7671 regulation in order not to compromise fire survival integrity.

Temperature limits depend on sheath material: SS316L/Inconel 600 to 800°C, SS446 to 1150°C, Pt10%Rh to 1300°C.

Resistance is maintained above 100 MΩ with high-purity MgO (≥99.4%) owing to its compressed crystalline structure as warranted by ASTM E839 testing.

Yes, bend radius must be a minimum of 2x the diameter; exposed ends must be resealed against moisture ingress immediately.

Metal sheathing provides mechanical protection and seals from environmental influences; MgO insulation electrically separates the conductors.

Yes, all thermocouple cables are provided with certificates with EMF values tested in accordance with ANSI MC 96.1; IEC 584-2; and ASTM E230.

MIMS cables should be stored in dry environments and factory end seals should remain intact, if a cut ends occurs then resealed immediately to protect hygroscopic MgO from moisture penetration.

LV cables are used in voltages up to a given limit of 1.1 kV; they send control signals or power to operate equipment. HV (high voltage) cables will operate at voltages above a given limit (generally above 1 kV but typically in the 11 kV-132 kV range or above), and are used to move bulk/power with increased insulation thickness and dielectric strength requirements.

LV cables generally work with identifiers from voltages of 50V to 1100V (1.1 kV); specifically, Tempsens control cables are built for a continuous rating of 1100 V as determined by the IEC 60502-1 and IS 1554 standards.

Choosing LV cable size requires calculations of the load current (using I = P/V), applying derating factors based on ambient temperature and installation method, identifying a permissible voltage drop (as a percent of the system voltage) that meets the voltage drop limits (which in practice means, it’s usually limited to below 3-5%). It’s also necessary to check a cable’s ability to withstand short circuit events, reference IEC 60228 conductor standards.

The minimum distance between HV and LV cables is commonly specified to be greater than 300 mm for unscreened cables or greater than 150 mm with a physical barrier present. All individual installations must ensure those minimum separations (or applicable separation distances) conform to local electrical codes as well as IEEE and IEC segregation guidelines to minimize interference concerns, and any overall safety concerns. 

Standard thermocouples have a 2-wire or (Positive and Negative Leg) configuration; the 3-wire adds the ground wire providing shielding and safety in electrically-noisy environments, but again, Thermocouples operate 2-wire inherently unlike the RTD style of temperature sensing.

Thermocouple cables can reach lengths of 300-500 meters depending on the gauge of wire and the electromagnetic interference (EMI) in the environment; anything beyond that, it is recommended to utilize signal amplifiers or signal transmitters to prevent noise related errors and to maintain an accurate measurement.

The temperature rating of the thermocouple cable varies based on insulation type.  PVC insulation can be rated in the range of -20°C to +105°C, while fiberglass braided cable can be continuous up to 400°C. Silicone rubber feeling can maintain -60 Celsius to +180 °C, while Teflon insulation can operate applications down to -200 Celsius to up to 260 Celsius.

Nichrome 80:20 is used extensively for heaters due to its high-temperature strength, electrical resistance, and stability.

Nickel alloys are applied in heaters, thermocouples, aerospace, chemical industry, and marine environments for their resistance to heat and corrosion.

Systemy śledzenia ciepła generują kontrolowane ciepło poprzez opór elektryczny w elementach grzejnych rozmieszczonych wzdłuż rur i powierzchni urządzeń. Kable samoregulujące automatycznie dostosowują moc wyjściową w zależności od warunków temperaturowych, natomiast systemy o stałej mocy zapewniają stałe ciepło niezależnie od temperatury otoczenia.

Przemysł chemiczny, naftowy i gazowy, farmaceutyczny, spożywczy, energetyczny i produkcyjny wykorzystują produkty do śledzenia ciepła w celu ochrony przed zamarzaniem i kontroli temperatury procesów. Każdy obiekt wymagający precyzyjnego utrzymania temperatury lub ochrony przed ekstremalnymi temperaturami może skorzystać z odpowiednio zaprojektowanych systemów śledzenia ciepła.

Nowoczesne systemy śledzenia ciepła wymagają minimalnej konserwacji, obejmującej okresowe kontrole wizualne i coroczne testy elektryczne rezystancji izolacji i ciągłości. Systemy Tempsens zawierają kompleksowe akcesoria, takie jak zestawy końcowe, skrzynki przyłączeniowe i panele sterowania, aby zapewnić niezawodne długotrwałe działanie przy minimalnych wymaganiach serwisowych.

Kabel MI to osłonięty kabel termoparowy, posiadający zewnętrzną osłonę z metalu z dwoma do ośmiu rdzeniami, gdzie dodatnie i ujemne elementy termoparowe biegną wokół wzoru kołowego, zatopionego w MgO. Kable izolowane mineralnie nadają się do wysokiej stabilności mechanicznej, chemicznej i elektrycznej. Ze względu na dobrą elastyczność, doskonałą wytrzymałość mechaniczną i odporność na ciśnienie, izolowane mineralnie termopary/RTD można instalować w złożonych instalacjach.

Budowa:

• Jeden lub więcej przewodów (rdzenie) o wysokiej jakości izolacji MgO (tlenek magnezu) jest zatopiony w metalowej rurce (osłonie) wykonanej z materiału odpornego na utlenianie i korozję. Następnie cała kombinacja jest przetwarzana przy użyciu odpowiednich etapów formowania w celu uzyskania ostatecznych wymiarów.

Przewód kompensacyjny wykonany jest ze stopów, które różnią się od stopów termopar, ale mają takie samo wyjście w ograniczonym zakresie temperatur. Przewód kompensacyjny to łącznik między termoparą a przyrządami pomiarowymi, kable te są mniej precyzyjne, ale tańsze. Wykorzystują one zupełnie inne, stosunkowo tanie materiały przewodzące ze stopów, których netto termopara jest przedmiotem zainteresowania. Połączenie rozwija podobne wyjście jak termopary, ale zakres temperatury roboczej musi być ograniczony, aby utrzymać błąd niedopasowania na akceptowalnie małym poziomie.

Kable MI obejmują szeroki zakres zastosowań. Poniżej wymieniono ważne informacje:

• W przemyśle chemicznym, petrochemicznym i nawozowym, a także jako wyposażenie w przemyśle mleczarskim, przetwórstwa spożywczego, farmaceutycznym, w szpitalach, gospodarstwach domowych jako naczynia kuchenne, naczynia kriogeniczne i jako wymienniki ciepła w chłodnictwie klimatyzacyjnym, w maszynach w sektorze papierniczym, celulozowym i tekstylnym.
• Listwy wykończeniowe architektoniczne, elementy zewnętrzne statków, sprzęt do przetwórstwa chemicznego, sprzęt do przetwórstwa żywności, sprzęt do rafinacji ropy naftowej, sprzęt fotograficzny.
• Elektrownie jądrowe i budowa reaktorów, inżynieria aparatury chemicznej, piece do wyżarzania, wymienniki ciepła, przemysł naftowy, przemysł smarowy i mydlany, kominy i kolektory wydechowe samolotów, zbiorniki ciśnieniowe, duże tłumiki do silników Diesla, gaźniki, miechy rozprężne, tuleje kominów, ściany ogniowe itp.
• Technologia energetyczna, rekuperaty, piece do obróbki cieplnej, instalacje do spalania wirowego, spalarnie odpadów, budowa pieców, kotły i wielkie piece, reaktory ciśnieniowe, podróże kosmiczne.

Przewód przedłużający wykorzystuje przewód nominalnie tego samego przewodnika co sama termopara, co z natury posiada podobne właściwości termoelektryczne i nie powoduje problemów z połączeniem. Błąd niedopasowania wynikający z wysokiej temperatury skrzynki połączeniowej jest prawdopodobnie stosunkowo niewielki. Te kable są mniej kosztowne niż przewody termoparowe, chociaż nie są tanie, i są zazwyczaj produkowane w wygodnej formie do przenoszenia na duże odległości, zwykle jako elastyczne okablowanie lub kable wielożyłowe. Są zalecane dla uzyskania najlepszej dokładności.