AEC WD 350 through WD3000 Dehumidifying Dryers - Manual (Page 42)

350-2100 cfm Dryers Chapter 6: Maintenance 41 of 58
6-10 Regeneration Heater Replacement Procedure
Dryer models 350 through 2100 Dryers have four or eight three-phase regeneration heaters wired in the
wye formation mounted in the insulated box directly above the lower valve.
WARNING! WARNING! Disconnect and lock out power before heater replacement.
1. Access the regeneration heaters from the rear of the dryer. Remove the cover plate secured by
two bolts.
3. Sketch the heater wiring configuration so the heaters may be re-assembled properly. Also, note
that the loops of the heaters are vertical to prevent drooping when hot.
4. Remove the jumper wires for the heater(s) being removed and/or replaced.
5. Remove the four bolts securing each heater's 3 1/2" mounting plate. Slide out the heater, taking
care to not damage the gasketing.
6. Re-install the new heaters in reverse order. Be sure their loops are vertical, like the original
heaters were. Securely tighten all fasteners.
Caution! Caution! The heater loops should not touch each other. This will create "hot
spots" and lead to premature heater failure.
7. Re-install the jumper wires according to the sketch made earlier.
8. Re-secure the regeneration heater access cover.