Polycab Thermocouple Extension Cable – KX and JX, Screened, Armoured or Unarmoured, BS EN 50288-7

The Polycab Thermocouple Extension Cable carries thermocouple signals to the instrument on conductors of the thermocouple's own alloys - KX for type K and JX for type J - insulated with XLPE or PVC, foil screened and sheathed in flame- and sunlight-resistant PVC. Polycab's catalogue lists it as conforming to BS EN 50288-7. It is supplied at a price on request: cable prices depend on the construction, the quantity and the raw-material prices on the day.

Polycab India Limited is India's largest manufacturer of wires and cables, with 27 manufacturing facilities, a network of 4,300+ dealers and distributors, 2,00,000+ retailers and an export presence in 84 countries (polycab.com, October 2026). Its cable range runs from house wires and 1.1 kV power and control cables to MV and EHV power cables, with instrumentation, solar, railway, marine, mining, fire-survival and other special cables. Jai Enterprises supplies Polycab cables from Bhilai and Raipur all over Chhattisgarh - Bhilai, Raipur, Durg, Korba, Bilaspur, Raigarh, Jagdalpur, Kanker, Ambikapur and every other district - and across India.

Is this the right one for you?

Check these four things before you order:

• You know the thermocouple type at each point - KX cable for type K, JX cable for type J.
• You know the number of pairs, the conductor size and whether each pair needs its own screen.
• You know whether the run needs armour.
• Terminals and connectors will be of the matching thermocouple alloy, wired with the correct polarity.

At a glance

• Price: on request - call +91 9340081159
• Product: Polycab Thermocouple Extension Cable
• Type: thermocouple extension cable
• Conductors: solid KX (type K: nickel-chromium / nickel-aluminium) or JX (type J: iron / constantan) alloys
• Insulation: XLPE or PVC
• Screen: individual and / or overall aluminium-Mylar tape with drain wire
• Armour: armoured or unarmoured
• Sheath: flame- and sunlight-resistant PVC
• Standards: BS EN 50288-7 (printed as EN 50288-7); type designations as in IEC 60584-3
• Source: Polycab B2B all-products catalogue (2025), p 14

Construction and standards

• Conductors: solid KX or JX thermocouple alloys
• Insulation: XLPE or PVC
• Screen: individual and / or overall aluminium-Mylar tape with drain wire
• Inner sheath: yes (material not stated in the catalogue)
• Armour: armoured or unarmoured
• Outer sheath: flame- and sunlight-resistant PVC
• BS EN 50288-7: instrumentation and control cables for analogue and digital signals, with maximum rated voltages of 90, 300 or 500 V AC; not for connection to mains power
• IEC 60584-3 (for reference - not listed in the catalogue for this cable): thermocouple extension and compensating cables - tolerances and identification (an "X" type is an extension cable)
• Source: Polycab B2B all-products catalogue (2025), p 14

Why choose the Polycab Thermocouple Extension Cable

• Conductors of the thermocouple's own alloys, so the reading reaches the instrument without adding a junction error (the cable's own tolerance class under IEC 60584-3 still applies)
• KX for type K and JX for type J thermocouples
• Individual and / or overall foil screen with drain wire
• Armoured or unarmoured
• Flame- and sunlight-resistant PVC sheath for outdoor plant runs

How to choose and specify it

Match the type. A thermocouple measures the temperature difference between its hot junction and the point where its alloys meet copper. An extension cable of the same alloys (KX for type K, JX for type J) moves that point to the instrument; a copper cable, or the wrong alloy, adds a new junction and a reading error.

Polarity and colour code. Connect positive to positive. Colour codes differ between standards (IEC 60584-3, ANSI and older national codes), so tell us which one your plant uses. In the ANSI code the red conductor is the negative leg; the positive leg is the nickel-chromium (KX) or iron (JX) conductor.

Terms. Under IEC 60584-3 an "X" cable (KX, JX) is an extension cable of the thermocouple's own alloys; in Indian practice these cables are often called compensating cables.

Screening and armour. Use individual screens on multi-pair cables near power cables or drives, and armour for buried or exposed runs. In hazardous areas, use Ex-certified glands suited to the cable - armoured or unarmoured.

Temperature. The XLPE or PVC insulation and the PVC sheath set the cable's temperature limit, which we confirm on the datasheet. Route the cable away from hot surfaces, or tell us the temperature on the route so that we can confirm a suitable cable.

Where it is used

• Furnaces, kilns and boilers
• Steel plants, foundries and forging shops
• Cement kilns and preheaters
• Power plant turbines and boilers
• Heat treatment and process heaters

Other Polycab instrumentation, data and fibre cables

• Polycab Instrumentation Cable - pairs, triads and quads, individually / overall screened, price on request
• Polycab VFD Cable - 3+3(E) and 4 core screened drive cable, price on request
• Polycab Thermocouple Extension Cable (this page) - KX and JX extension cable, price on request
• Polycab Bus Cable - Profibus and Fieldbus cable, price on request
• Polycab BMS Cable - screened multicore BMS cable, price on request
• Polycab Data Cable - RS485, LIYY and LIYCY, price on request
• Polycab Optical Fibre Cable - OFC for telecom, BharatNet, smart city and enterprise networks, price on request

Related products

• HEX Nickel-Plated Brass Cable Glands - IP68 Metric & PG Thread, Plus PG Unarmoured Glands; for the unarmoured versions in safe (non-hazardous) areas
• HEX CW Brass Cable Glands - IP66 Weatherproof Armoured Cable Glands, 16S to 90L; for the armoured versions in safe (non-hazardous) areas

Frequently asked questions

What is the price of the Polycab Thermocouple Extension Cable?

The Polycab Thermocouple Extension Cable is supplied at a price on request, because cable prices depend on the construction, the quantity and the raw-material prices on the day. Call +91 9340081159 for a quotation.

KX or JX - which do I need?

KX for type K thermocouples (nickel-chromium / nickel-aluminium) and JX for type J (iron / constantan). The cable must match the thermocouple type.

Can I use ordinary copper cable?

No - joining a thermocouple to copper wire away from the instrument creates a new junction and a reading error. Use an extension cable of the matching alloy.

Is this a compensating cable?

In Indian practice KX and JX cables are often called compensating cables. Under IEC 60584-3 they are extension cables, made of the same nominal alloys as the thermocouple.

Where can I buy the Polycab Thermocouple Extension Cable in Chhattisgarh?

From Jai Enterprises, Bhilai and Raipur, which supplies Polycab cables to every district of Chhattisgarh and across India. Call +91 9340081159 for the price, stock and lead time.

How to order

Price on request: call +91 9340081159 or send an enquiry from this page with KX or JX, the number of pairs and the conductor size, XLPE or PVC insulation, the screening, armoured or not, the colour code, the temperature on the route, the length and the delivery location, and we will confirm the price, availability and lead time. Ask for the Polycab datasheet for your exact construction before you order.