AEC TD Floor Mount Dryers - Manual (Page 15)

OPERATING MANUAL - TD2 & TD4-25-100 DRYERS
Revision 8/31/01
Page 15
Check the limit first by pressing the SET button on the
temperature control and holding until AL is displayed. The
setting shown indicated the amount over set point that the
alarm will be actuated. It is factory set to 50°F (30°C) and
should not be set below 30°F (16°C) or it will actuate too soon.
If the temp exceeds the set point check the following:
1. Remove the hose from the top of the hopper to check air
flow. There should be air flow out of the hopper with a
suction on the hose. If there is little or no flow, check the
inlet hose.
2. Inspect the filter to make sure that it is clean and not
affecting the air flow.
3. Check the power boards to see if one of the solid state
relays has failed on. Using an ammeter or voltmeter on
the output to the heater, see if there is power when the
LED is not lit which will indicate a failed relay.
4. Check the valve position.
The rotary zone valve is designed to provide very little flow
restriction and no leakage. It incorporates high temperature,
self adjusting seals for years of trouble free service. The
electrical controls are built into the end of the valve and
include position lights.
Trouble shooting is easy. If the lights indicating position do not
match the zone displayed on the control panel, or there are no
lights, the valve is not working properly. See if the cam is
actuating a switch.
DO NOT PUT FINGERS INTO VALVE WITH POWER ON
Check all electrical connections to make sure they are tight.
Contact factory with the serial number of the dryer for a
replacement valve.
ROTARY ZONE VALVE