Selection and Sizing of Insulation · 2020. 2. 1. · Field Instrument Cable Selection and Sizing...

Post on 09-Mar-2021

9 views 0 download

transcript

1

Field Instrument Cable

Selection and Sizing of Insulation

2

Cable Construction Standards • 300 Volt UL 13 PLTC / ITC • 600 Volt UL 1277 TC • International Standards

– CSA # 239 Control and Instrumentation • 300 & 600 Volt PVC insulation & jackets with steel and

aluminum interlocked armor optional

– IEC 502 600/1000 Volt for PVC & XLPE insulations – IEC 227 450/750 Volt for PVC insulation – BS 5308 300/500 Volt for PVC & HDPE insulations – BS 6346 & 5467 600/1000 Volt for PVC & XLPE

insulations

3

Types of Insulation Instrumentation Cables 300 Volt Thermoplastic – PVC, TPE, HDPE Thermoset – XLPE, silicone 600 Volt Thermoplastic – PVC/Nylon, HDPE, PVC Thermoset – XLPE, silicone Thermocouple Extension Cables 300 Volt Thermoplastic – PVC Thermoset – XLPE 600 Volt Thermoplastic – PVC/Nylon, HDPE, PVC Thermoset – XLPE Control Cables 600 Volt Thermoplastic – PVC/Nylon, HDPE Thermoset – XLPE, silicone

4

Standards Reference

5

Insulation Thickness -300V

6

Insulation Thickness –600V

7

Electrical Properties per Insulation material and thickness

8

Properties of Insulations Insulation Dielectric Constant

PVC 4.5 XLPE 2.4 HDPE 2.3 FEP 2.1 Silicone Alloy 2.9

9

Insulation Key Key Material Advantages Disadvantages

PVC Low Cost Fair Electrical Properties

General Purpose Fair Cold Properties

Flame Retardant High Chlorine Content

PVC/NYLON General Purpose Fair Electrical Properties

Flame Retardant Fair Cold Properties

Toughness Stiff

Thermoplastic Insulation Performance

10

Insulation Key Key Material Advantages Disadvantages

XLPE Excellent Electrical Modest Cost

Excellent Cold

Flame Retardant

SILICONE CIC Cost

Excellent Electrical

Zero-Halogen

Thermoset Insulation Performance

11

12

Field Instrument Cable

Selection and Sizing of Jackets

13

Types of Jacket Options – PVC PolyVinylChloride – CPE Chlorinated PolyEthylene – LDPE Low Density PolyEthylene – TPE ThermoPlastic Elastomer – TPN ThermoPlastic Non-Halogen – HYPALON (CSPE) synthetic rubber

14

Jacket Performance Insulation Key Key Material Advantages Disadvantages

PVC Low Cost Fair Cold Flame Retardant High Chlorine CPE Good Chemical Moderate Cost Good Cold Flame Retardant Hypalon Good Chemical Moderate Cost Good Cold Ozone & Weather Flexible

15

16

Field Instrument Cable

Selection and Sizing of Jacket

Chemical Resistance Data for Insulation and Jacket Material

17

18

Field Instrument Cable

Selection and Sizing of Armor

Armoring Options Available

19

Types of Armoring Options Interlock armor, galvanized steel or aluminum Served Wire armor, galvanized steel wires, Dekabon® aluminum moisture & chemical barrier, environmentally safe replacement for lead sheathing. Continuously Welded Corrugated Aluminum Gardex®

20

Temperature Measurement

• Thermocouple wire • Thermocouple extension wire • RTD sensor

21

Thermocouple Extension Cable

A thermocouple is created when two dissimilar (special alloy) metals are joined together. As the temperature at the junction increases the voltage output increases. The instrument converts the voltage to a temperature. Thermocouple extension connects the thermocouple to the instrument.

Measuring Temperature

23

Resistance Temperature Detector (RTD)

Produces a very linear change of resistance with changes in temperature Standard is 100 Ohm Platinum RTD Range is -200C to 850 C (1560 F) 3 wire most commonly used

24

Advantages Thermocouples

Self Powered Rugged Inexpensive Wide Temperature Range ( to 3310 F)

RTD Most Accurate Most Stable

25

Disadvantages

Thermocouple Non-linear Low Voltage Output Less Stable Reference Temp Required

RTD Expensive

26

Comparison of Standards Color code for ANSI, IEC and BS