Plastics catalog - Watlow - (Version JPG) - Page n° 59 - PDF Catalogue | Technical Documentation

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Heater, Controller, Power regulator, Tubular heater, Cable

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irrel Heate

Problem Solvers

Watlow Solutions To Common Barrel Heater Problems

Torque Details for Barrel Heater Screws

If barrel heater clamp screws are snapping off during maintenance, screws are being tightened beyond their limits. Please reference chart to the right for installation information.

MI,THINBAND and Mica Clamp Torque Chart


	Nickel Plated, Dry Standard	Nickel Plated, Anti-Seize	Black Oxide, Dry	Black Oxide Anti-Seize
Clamp Screw Size	Torque (in.-lb)	Torque (in.-lb)	Torque (in.-lb)	Torque (in.-lb)
UNC #6-32	30	20	20	15
UNC #8-32	40	30	25	20
UNC #10-24	55	35	35	30
UNC 1/4-20	80	55	50	45
UNC 1/4-20 w/springs	40	40	N/A	N/A
M6-1	80	55	50	45
M5-0.8	60	40	35	35

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Heater Solution

Problem

1. Wiring Considerations:

• If heaters are dual voltage, check wiring to ensure that heater halves are wired in series for higher voltage installation.

• Check incoming voltage for over voltage condition.

2. Installation Considerations:

• Since most heaters transfer heat through conduction, it is essential that heaters fit tightly to the machine barrel. Check installation instructions to ensure that heaters are clamped to torque values indicated. See MI, THINBAND and Mica Clamp Torque Chart above:

• Ensure that dirt and grit are removed prior to installation. Any foreign matter under the heater will interfere with proper heat conduction.

3. Thermal Considerations:

• Review application and clamping graphs to ensure heater watt density is not excessive.

• Examine machine to evaluate thermal mass in a particular zone. High thermal mass can conduct heat away from zone being heated, driving up heater temperature as heater expands away from barrel.

Heaters glow red on startup before reaching barrel set point.

Plastics catalog - Watlow - #59

Heater, Controller, Power regulator, Tubular heater, Cable