Square & Rectangle Cartridge/Immersion Heaters

 

SQUARE & RECTANGLE CARTRIDGE HEATERS MILLED SLOTS

Square Rectangle Cartridge Heaters with Milled Slots
Description

U.L. Recognized – E56973
C.S.A. Certified – 016386-0-000

Features
  • The Backer Hotwatt Square and Rectangular Cartridge Heater is designed to distribute maximum heat within a desired area. Because they are completely enclosed,square units will furnish more usable heat for a given wattage than a comparable strip heater attached to the exterior of a mold, platen, or other equipment.
  • The units are inserted in a milled slot, permitting greater lengths than would be feasible with a drilled or reamed hole. Close dimensional tolerances are held to permit intimate fit for best heat transfer to surrounding medium.
  • Heating elements arranged just beneath outside surface for maximum heat transfer, minimum wire temperature, and faster heating.
  • Maximum surface temperatures up to 1200°F. Designations are etched on the sheath to preserve accurate shape.
  • Long, trouble free service.
  • Made in U.S.A.
Description
Square Rectangle Cartridge heaters with Milled Slots Illustration
  1. Sealed end.
  2. Mica.
  3. Series 300 stainless steel sheath for non-oxidizing, stable service in cavities machined for them.
  4. Element wire situated in close proximity to outside surface for maximum heat transfer, minimum wire temperature, and faster heating.
  5. Magnesium oxide packing.
  6. Ceramic element support.
  7. Teflon insulated leads: 1/4″ square. Fiberglass insulated leads: 3/8″ to 1/2″ square, 1/4″ x 5/8″ and 1/4″ x 1″ rectangular.
Square

Lengths between or longer than those listed may be ordered.

 

Size: 1/8″ x 1/8″ (.124/.210 x .124/.120)

Maximum Amperage: 1 Not UL/CSA

Sheath
Length

Cat.No.

Min.
Watts

Max.
Watts

1″

SS12-1

10

15

2″

SS12-2

10

35

3″

SS12-3

10

55

4″

SS12-4

10

75

5″

SS12-5

10

95

6″

SS12-6

10

115

7″

SS12-7

10

135

8″

SS12-8

10

155

9″

SS12-9

10

175

10″

SS12-10

10

195

11″

SS12-11

10

215

12″

SS12-12

10

235

For longer lengths, compute wattage at: 10 watts per linear 1/2″

Square

Size: 1/4″ (.249/.245 x .249/.245)

3/8″ (.374/.370 x .374/.370)

1/2″ (.499/.495 x .499/.495)

Maximum Amperage: 3.5

6

10

Sheath
Length

Cat.No.

Min.
Watts

Max.
Watts

Cat.No.

Min.
Watts

Max.
Watts

Cat.No.

Min.
Watts

Max.
Watts

2″

SS25-2

10

60

SS37-2

10

90

SS50-2

10

130

3″

SS25-3

10

100

SS37-3

10

150

SS50-3

10

210

4″

SS25-4

10

150

SS37-4

10

210

SS50-4

10

300

6″

SS25-6

10

225

SS37-6

10

330

SS50-6

10

500

8″

SS25-8

10

350

SS37-8

10

450

SS50-8

10

700

10″

SS25-10

10

450

SS37-10

10

570

SS50-10

10

850

12″

SS25-12

10

550

SS37-12

10

690

SS50-12

10

1000

16″

SS25-16

10

750

SS37-16

10

930

SS50-16

10

1280

18″

SS25-18

10

840

SS37-18

10

1050

SS50-18

10

1440

24″

SS25-24

10

840

SS37-24

10

1410

SS50-24

10

1920

For longer lengths, compute wattage at:
840 watts max. 30 watts per linear 1/2″ 40 watts per linear 1/2″

Wattage

Minimum Wattage

The following table should be used to determine the allowable voltage for low wattage miniature elements:

 

Size:

1/8″ Square

3/16″ Square

Length

30v

60v

120v

230v

30v

60v

120v

230v

1″

.6w

2.5w

10w

NA

.8w

3w

12w

NA

1 1/2″

.6w

2.5w

10w

NA

.5w

2w

8w

30w

2″

.5w

2w

8w

27w

.4w

1.5w

6w

22w

NA – Not Available

Voltage

Standard voltage is either 120V or 240V. Other voltages are available.

Termination

All units within published amperage limits, are manufactured with 6″ (type SF1) leads; longer length leads are available. Standard insulation on 1/4″ square units is Teflon (200°C). Fiberglass (250°C) is standard on all other sizes.

Rectangular

Lengths between or longer than those listed may be ordered.

 

Size: 1/8″ x 1/4″ (.124/.120 x 249/.245)

1/8″ x 3/8″ (.124/.120 x .374 /.370)

Maximum Amperage: 2

3.5

Sheath
Length

Cat.No.

Min.
Watts

Max.
Watts

Cat.No.

Min.
Watts

Max.
Watts

1″

SR14-1

10

20

SR13-1

10

35

2″

SR14-2

10

55

SR13-2

10

90

3″

SR14-3

10

85

SR13-3

10

140

4″

SR14-4

10

110

SR13-4

10

190

5″

SR14-5

10

135

SR13-5

10

240

6″

SR14-6

10

170

SR13-6

10

290

7″

SR14-7

10

200

SR13-7

10

340

8″

SR14-8

10

230

SR13-8

10

390

9″

SR14-9

10

260

SR13-9

10

440

10″

SR14-10

10

290

SR13-10

10

490

11″

SR14-11

10

320

SR13-11

10

540

12″

SR14-12

10

350

SR13-12

10

590

For longer lengths, compute wattage at:

15 watts per linear 1/2″ 25 watts per linear 1/2″

Rectangular

Lengths between or longer than those listed may be ordered.

 

Size: 1/4″ x 5/8″ (.249/.245 X .624/.620)

1/4″ x 1″ (.249/.245 X .999/993)

Maximum Amperage: 6

10

Sheath
Length

Cat.No.

Min.
Watts

Max.
Watts

Cat.No.

Min.
Watts

Max.
Watts

1″

SR15-1

10

35

SR16-1

10

50

2″

SR15-2

10

100

SR16-2

10

150

3′

SR15-3

10

175

SR16-3

10

300

4″

SR15-4

10

250

SR16-4

10

400

5″

SR15-5

10

320

SR16-5

10

500

6″

SR15-6

10

455

SR16-6

10

600

7″

SR15-7

10

560

SR16-7

10

700

8″

SR15-8

10

640

SR16-8

10

800

9″

SR15-9

10

720

SR16-9

10

900

10″

SR15-10

10

800

SR16-10

10

1000

11″

SR15-11

10

880

SR16-11

10

1100

12″

SR15-12

10

960

SR16-12

10

1200

16″

SR15-16

10

1280

SR16-16

10

1600

18″

SR15-18

10

1440

SR16-18

10

1800

24″

SR15-24

10

1440

SR16-24

10

2400

For longer lengths, compute wattage at:

35 watts per linear 1/2″ 50 watts per linear 1/2″

Rectangular

Wattage tolerances are held to +5%, -105 at rated voltage. Width and height are always .001″ less but not more than .010″ less than the nominal (fractional) heater size; length tolerances are ±2% with a ±1/16″ minimum. This sizing is maintained so that all units are a slide fit into a standard milled slot of the size required. Thermal action will expand the unit to a snug fit for best heat conduction.

Rectangular

After determining the wattage required and the line voltage available, determine the physical space available for heaters and the numbers of heaters required. Review Special Features.

 

Specify: catalog number, wattage, voltage, lead length, and special features required.
Example: SR16-7.5/750W/240V/SF1-48.