Problem

 

Possible cause

 

Corrective action

 

 

 

 

 

 

 

 

 

Process heaters are faulty.

 

Check for open heaters. Replace

 

 

 

 

if required.

 

 

 

 

 

 

 

 

Solid-state temperature

 

Replace.

 

Loss or reduction of process air

 

controller faulty.

 

 

 

 

 

 

 

 

 

Make sure that plant personnel

 

temperature.

 

 

 

 

 

Process temperature was

 

are aware of the proper

 

 

 

 

 

 

 

adjusted in error by plant

 

temperature set point. Post an

 

 

 

personnel.

 

appropriate sign next to the

 

 

 

 

 

controller.

 

 

 

Process heaters are faulty.

 

Replace.

 

 

 

Desiccant beds are

 

Replace desiccant.

 

 

 

contaminated.

 

 

 

 

 

 

 

 

 

 

 

Drying systems are designed for

 

 

 

Material being dried differs

 

the material which was

 

 

 

 

originally specified. Different

 

 

 

from material specified at the

 

 

 

 

 

materials may need a longer

 

 

 

time of purchase.

 

Loss or reduction in drying

 

 

residence time or a different

 

 

 

 

 

 

drying temperature.

capacity.

 

 

 

 

Break in flex hose to/from

 

Inspect for air leaks; replace as

 

 

 

 

 

 

 

drying hopper.

 

needed.

 

 

 

Airflow valve sticking or failing

 

Check for proper operation of

 

 

 

 

valve actuators. Repair or

 

 

 

to shift.

 

 

 

 

 

replace if necessary.

 

 

 

 

 

 

 

 

Blower fins filled with dust or

 

Remove blower side plate,

 

 

 

 

clean baffles, replace.

 

 

 

contaminants.

 

 

 

 

 

Replace filter elements.

 

 

 

 

 

 

 

 

Insufficient power to PLC

 

Check power supply and power

 

PLC Regeneration Bed LED

 

(Power LED is off).

 

wiring to PLC.

 

 

Faulty PLC (PLC Power light is

 

 

 

indicators both off.

 

 

Replace PLC.

 

 

on, Run light is off, and/or Error

 

 

 

 

 

 

 

 

light is on).

 

 

 

 

 

Regenerating bed cooldown.

 

None.

 

 

 

Blower Input indicator is off.

 

Verify that blower contactor is

 

 

 

 

on. Check input wiring to PLC.

 

 

 

 

 

 

PLC Regeneration Heater

 

Process air in high-temperature

 

None.

 

 

condition.

 

 

Left/Right output indicators both

 

 

 

 

 

Insufficient power to PLC

 

Check power supply and power

 

off.

 

(Power light is off).

 

wiring to PLC.

 

 

 

 

 

 

 

Faulty PLC (PLC Power light is

 

 

 

 

 

on, Run light is off, and/or Error

 

Replace PLC.

 

 

 

light is on).

 

 

Dehumidifying Dryers

Chapter 6: Troubleshooting

49 of 59

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Image 50
Sterling SDAA 25-100 specifications Problem Possible cause Corrective action