Shutdown; Maintenance Schedule; Daily - Sigma HRD Serie Manual De Instrucciones

CAUTION
The desiccant beds may fluidize at excessive
airflow rates. Refer to Table 3, page 1-11.
Airflow surges may also cause fluidization.
Surges may occur if the dryer is not started in
accordance with instructions or if the dryer is
located downstream of a receiver.
Conditions that cause fluidization must be
avoided. Fluidization causes excessive
dusting and rapid degradation of the
desiccant, reducing its effective life. Desiccant
dusting causes valves to wear and malfunction
and filters to plug up rapidly.

Shutdown

If the dryer or the air system is shut down desiccant
life can be prolonged by venting the dryer internal
pressure to the atmosphere.
To vent dryer pressure:
1. Turn the power switch OFF.
DANGER
EXPLOSION HAZARD
Dismantling or working on any component of
the compressed air system under pressure
may cause equipment damage and serious
injury. Before dismantling any part of the dryer
or compressed air system, completely vent the
internal air pressure to the atmosphere.
2. Open the customer-supplied bypass valve (if in-
stalled).
3. Close the customer-supplied shutoff valve down-
stream of the dryer.
4. Close the customer-supplied shutoff valve up-
stream of the dryer.
5. Slowly open the customer-supplied depressuriza-
tion valve to vent the dryer internal air pressure.
6. When the internal air pressure is 0 psig, close the
depressurization valve.
Restart the dryer according to the start-up instructions
on page 1-9.
If electrical maintenance must be performed on the
dryer, electrical power to the dryer must be locked out
and tagged in accordance with OSHA requirements.
1-12
DANGER
SHOCK HAZARD
Portions of the electrical control circuit remain
energized when the power switch is turned
OFF. Disconnect the main power supply to the
dryer before performing maintenance on the
electrical system.
Before performing electrical maintenance:
1. Turn the power switch off.
2. Disconnect the main power supply.

Maintenance Schedule

The following periodic checks should be made to
monitor dryer operation. These inspections will help
you schedule servicing to ensure continuing good
dryer performance and safe operation. Maintenance
kits are available from your local distributor (see page
A-1 for a description of each kit.
Action
Check automatic drain valve
Check system monitor lights
Check filter differential pressure indicators
Check exhaust mufflers
Check purge exhaust valves
Inspect internal float drain on filters (if equip-
ped)
Inspect desiccant
Replace solenoid and butterfly valve dia-
phragms and seats
Replace prefilter and afterfilter elements.
CAUTION
Contact your local distributor before doing any
work on the solid state controls. Attempting to
service circuit boards or components may
result in equipment damage and will void the
warranty.

Daily

1. For dryers rated 600 to 3,250 scfm, check the fil-
ter above the dryer inlet.
2. Check automatic drain valve on prefilter (if
equipped) for discharge. If no condensate dis-
charges from drain valve, follow Shutdown proce-
dure (page 1-12), then dismantle and clean, repair
or replace drain valve as required.
HRD and HRD-EM Series (Bulletin 378)
Schedule
Daily
Daily
Weekly
Weekly
Weekly
Monthly
Yearly
Yearly
Yearly