Sullair SD-600 - 3.2.4 Alarms

INSTALLATION, START-UP & MAINTENANCE MANUAL
MODEL NO.: SD-220 TO SD-600- DDS OPTION
REV 0 – May 24,,.2001
16
SECTION 3
3.2.3 Operating sequence (DDS option) – (Continued)
STEP 6 LEFT CHAMBER REPRESSURIZATION.
- Keep energized EV-1R.
- De–energize EV-2L closing left chamber dump/exhaust valve.
- The repress timer begins a countdown of 45 sec. (See note 1)
- Inlet valve remains in current position.
NOTE 1: EV-3 and repress valves could be used if dryer operating at pressure
above 125 PSI (G) and / or dryer operating on a timing cycle other
than 10 minute cycle. Refer to the specification sheet in this manual
or to the flow schematic supplied with the dryer.
NOTE 2: If power failure occurs to the dryer or unit is turned off, both exhaust
valves will close. The inlet valve will remain in their position.
NOTE 3: The actual timer setting may differ from the previously noted
sequence. Example: A dryer requiring 30 seconds to re-pressurize the
regenerating chamber will have a regeneration time of 4 minutes and
30 seconds. The half cycle time will remain at 5 minutes and full cycle
at 10 minutes.
NOTE 4: The regeneration and repressurization times should be adjusted by
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trained personnel only. Changing the factory settings will result
in loss of dewpoint and/or failure to repressurize before changeover.
3.2.4 Alarms
COMMON ALARM RELAY
Common alarm relay comes with any optional alarm. If any one of the alarms are
activated, the common alarm relay will also be activated.
SWITCHING FAILURE ALARM (OPTIONAL, INCLUDED WITH DDS OPTION)
Two pressure switches, sensing desiccant chamber pressure, are provided. An
alarm will be activated if both chambers remain at full pressure when regeneration
is required. Furthermore, if pressure in both chambers remain below set pressure,
after depressurization an alarm will be activated.
NOTE: Dryers equipped with DDS and operating in the DDS mode do not
depressurize during the purge cycle (and do not purge) when an
acceptable dew point is maintained. During this condition, the
switching failure alarm is cancelled.
The alarm has a one-(1) minute delay.