Sterling SDAA 25-100 specifications Replacing the Process Heater, Procedures

Replacing the Process Heater

The dehumidifying dryers utilize a single-phase Calrod-type heater element. This heater element is mounted in the center compartment below the desiccant beds. Although the replacement procedure is the same for each heater, the wattage varies by model, voltage, temperature range, etc.

WARNING! Hazardous electrical current present.

Disconnect and lock out power before you replace heater elements!

Figure 13: Process Heater Location and Disassembly

Undo (6) 10-32 Button

Head Screws using 1/8

Allen Wrench

1" Wide x 1/8" Thick High

Temperature Gasket

(2) 4-40 screws

Hi Temperature

Snap Switch

Procedures

1.Remove the six (6) 10-32 button head screws securing the process heater access cover using a 1/8” Allen wrench.

2.Sketch the heater wiring configuration so you can properly re-wire the heater.

3.Remove the wires to the heater plate assembly being removed or replaced.

4.Remove the two (2) 4-40 screws securing the heater plate assembly, and slide out the assembly.

5.Remove the heater from the mounting plate by removing the large brass nuts and washers.

6.Re-install the heater and heater plate assemblies in reverse order. Install new heater gaskets and securely tighten all fasteners.

Caution! Heater loops should not touch each other. “Hot spots” lead to premature heater failure!

7. Reinstall the wires based on the sketch you made earlier.

Dehumidifying Dryers Chapter 5: Maintenance 47 of 59