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5.14 Alarm R6 - Incomplete heating, right tower, regeneration cycle
1. Desiccant bed overloaded on previous
• See Section 5.10.1.
drying cycle
2. Heater outlet temperature too low
• Incorrect (low) setting on heater temperature controller (TC1) - adjust
to factory setting.
• Electrical short in heater element(s) - check resistance of each phase
in the heater circuit.
3. Incorrect (high) setting on right purge
• Check switch operation, using temperature gauge (TI2) for compari-
temperature switch (TS2)
son. Readjust switch setting or replace switch if defective.
4. No power to heater
• Check wiring and control components in heater circuit. Repair as
necessary.
• Heater outlet thermocouple - check thermocouple circuit for conti-
nuity. Repair or replace as necessary.
• Low or no blower pressure - check for alarm R4 (see Section 5.12).
• Heater outlet temperature controller (TC1) malfunction - check
controller operation. Repair or replace controller as necessary.
5. Restricted or blocked purge air flow
• See Section 5.13.3.
6. Low pilot air pressure (PPS)
• Check switch operation, check system pressure.
5.15 Alarm R7 - Failure to repressurize, right tower, regeneration cycle
1. Faulty right tower pressure switch (PS2) • See Section 5.9.3.
2. Right purge valve (V4) failed to close
• See Section 5.9.5.
3. Right depressurization valve (V6)
• See Section 5.9.6.
failed to close
4. Repressurization valve (V15) failed
• Loss of pilot air - see Section 5.1.4.
to open
• Pilot valve (V16) failure - check valve operation. Repair or replace as
necessary.
• Repressurization valve (V15) - examine valve and actuator for damage.
Repair or replace as necessary.
5. Repressurization orifices (O1,O2)
• Check orifices for obstruction and clean as necessary.
blocked
6. Right purge check valve (V10) leaking
• Check for reverse air flow through heater and blower, i.e., out of the
blower intake filter (F1) and examine check valve internals. Repair or
replace as necessary.
CAUTION:
Air flowing backwards through heater and blower may be
very hot.
5.16 Alarm R8 - High outlet dew point, left tower, drying cycle (optional)
1. Incomplete regeneration
• Check for Alarm R6 (see Section 5.14)
2. Desiccant bed overloaded
• See Section 5.2.1
3. Loss of desiccant drying capacity
• See Section 5.2.5
4. Insufficient sample flow to transmitter
• Ensure isolation valve in sample line is fully opened.
• Ensure flow cell inlet filter is not clogged. Clean or replace.
• Ensure flow cell outlet (orifice) fitting is free of obstructions.
5. Alarm set point too low
• Check alarm set point (see menu #7) and adjust as necessary for dryer
operating conditions.
POSSIBLE CAUSES
CORRECTIVE ACTION
