Flexible Heaters Design Guide - MINCO - (Version JPG) - Page n° 9 - PDF Catalogue | Technical Documentation

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RTD, Thermocouple type K, Heating element, Temperature transmitter, Programmable transmitter

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Maximum Watt Density

The watt density tables on this page show the maximum allowable power for each heater type, expressed in watts per square inch, or centimeter, of effective area. The rating depends upon the heater's insulation/internal adhesive, heat sink control temperature, and the mounting method.

If watt density exceeds the maximum rating, the heater is in danger of overheating and premature failure. To obtain more power:

• Select a larger size heater

• Consider other heater materials, e.g. mica

• Change the mounting method

• Use proportional control to reduce power as the heat sink temperature rises

• Contact Minco for product and design assistance

In addition to wattage, you should calculate the current (I) through the heater leadwires to keep it within the maximum rating for the AWG wire size used.

Using watt density charts

1. Look up the effective area for the heater model in question. This is total heater area minus borders and lead attachment space (calculated by Minco).

2. Divide the power requirement in watts by this area to obtain watt density.

3. Draw a line from the heat sink temperature (at the bottom of the chart) to the line labeled with the mounting method and/or insulation you have chosen.

4. The maximum watt density is indicated by the value on the left or right axis that corresponds with that intersection.

Polyimide/FEP Heaters

-148°f -103°f -58°f -13°f 32°f 77°f 122°f 167°f 212°f 257°f 302°f 347°f 392°f 437°f

Silicone Rubber Heaters (foil)

-148°f

482°f

-58°f

32°f

122°f

212°f

302°f

392°f

65 r


MOUNTI	NG METH	OD

	— #20 S N Tap	e —r

#	2 PSA —S




		#6	RTV —^


HEATER: 0.008" SIL	CONE RUB	BER (0.2m	m)	Vu	canized —■

10.1

9.3

8.5

7.0

6.2

■s³⁵

£ 30 25

5.4

1 I

■It

II ä

50°c 100°c

Heat Sink Temperature

-50°c

0°c

150°c

200°c

250°c

Note: Find the silicone rubber heaters (wire-wound) watt density chart on page 32

Mica Heaters

-328°f

-148°f

32°f

212°f

392°f

572°f

752°f

932°f

1112°f


HEATER:				MOU	NTING ME	THOD:
				Clam	ped

•—	1.010" (0.3n	im) Mica-




	0.020"	(0.5mm) M	ca *

					\

18.6

0 Ï a- ~

e I

1 ï

It ì i

10.9

0.0

0 i

-200°c

0°c

Thermal-Clear™ Transparent Heaters

-76°f -22°f 32°f 86°f 140°f 194°f 248°f 302°f

3.88

MOU

NTING

METH

,—B

A3 Shri

ik Band

12 PSA

w/ Alu

minum

^Strc

tch tap

• or Cla

nped

Acrylic

PSA w/ ylic PSA

Alumin

Acr

HEAT

0.002' 0.001'

POLYIM ADHES

HIDE (0 IVE (0.0

05mm 3 mm)

#15

Epoxy

3.3



			MO Acr	UNTING M ylic PSA	ETHOD:


HEATER: 0.002" PO 0.002"AD	LYESTER (0.0 HESIVE (0.05	5mm) mm)

3.10

I o

5 >

Q. O

I 1

l'i .1 s

6.:

2.33

4.65

1.55

1 3

3.1

0.78

1.55

0.00

-60°c -30°c 0°c 30°c 60°c 90°c 120°c 150°c

-100°c -75°c -50°c -25°c 0°c 25°c 50°c 75°c 100°c 125°c 150°c 175°c 200°c 225°c

Note: Find the All-Polyimide heaters watt density chart on page 41

Flexible Heaters Design Guide | www.minco.com

Flexible Heaters Design Guide - MINCO - #9

RTD, Thermocouple type K, Heating element, Temperature transmitter, Programmable transmitter