Operation - SPX Hankinson HHE Series Instruction Manual

9.

OPERATION

9.1 Start-up
9.1.1 Controller Settings (Level 1 or Level 2 Controller)
• Set or verify settings on the Level 1 or Level 2 Controller. General
information regarding both controllers can be found in Section 5.
Detailed operational points are presented in Sections 7 and 8.
WARNING - Enclosure may have live electric parts. De-energize
dryer before opening enclosure.
• If a Cycle or Energy (purge) Savings % change is made while the
dryer is operating, the change will occur at the end of the current
half-cycle. If it is necessary to begin a new selection immediately,
shut the unit off and then back on.
NOTE: A tower that is actively purging when the power on/off
button is actuated will be subjected to a rapid repressurization
that can lead to fluidization and subsequent abrasion of the
desiccant bed. Ideally, dryers should only be powered off during
those portions of the drying cycle when both desiccant towers
are at full operating pressure.
• If switching to a cycle mode producing a lower dew point (e.g. 0°F
to -40°F [-17.8°C to -40°C]) while the dryer is operating, one or
two days of operation may be needed before the new dew point
is achieved.
9.1.2 Initial Pressurization
• SLOWLY pressurize dryer to full line pressure. (If the dryer was
installed with inlet and outlet isolation valves, the inlet isolation
valve should be slowly opened while the outlet isolation valve
remains closed.)
• During initial start-up, check the entire system for leaks. If
necessary, de-pressurize the dryer and correct any leaks.
9.1.3 Energizing the Dryer
• (Timer Based Controller) Energize the dryer using the disconnect
fuse located next to the customer connections in the bottom of
the control box.
• (Level 1 or Level 2 Controller) Energize the dryer using the power
switch located on the control panel.
• NOTE: The switching failure alarm may be activated if the unit
is energized before it is pressurized. To deactivate alarm, allow
dryer to cycle to next step and press the reset button.
9.1.4 Adjusting the Purge Rate
Determine the following:
• Maximum operating pressure (MOP) of dryer from the dryer serial
number tag.
• Air pressure at inlet to dryer.
• ISO Class cycle setting (Class 1, 2, 3, or 4).
NOTE: For units with the Level 2 Controller and the Automatic
Purge Saving System in the demand cycle mode use the ISO
Class 2 (10 min.) purge pressure settings only.
• Energy (purge) Savings % setting. This setting is applicable to
the Level 1 Controller only.
9.1.4.1 Purge Rate Pressure – Models 40 to 3000
• Refer to Table 9-4 for the proper purge rate pressure setting
corresponding to the conditions listed in Section 9.1.4.
NOTE: For units with the Level 2 Controller and the Automatic
Purge Saving System in the demand cycle mode use the ISO
Class 2 (10 min.) purge pressure settings only.
• Adjust purge rate valve until purge pressure gauge indicates
the required pressure. The purge pressure adjustment valve
on Models 40 through 3000 is a quarter-turn ball valve located
in the smaller bypass line of the upper piping of the dryer. Refer
to Figures 4-2 or 4-3 for location. Models 40 through 3000 use
a double orifice purge circuit. Equally sized orifices are located
at either end of the bypass line. The purge pressure adjustment
valve, and a pressure tap for the purge pressure gauge are piped
between the two orifices. Looking at the front of the dryer, when
the left tower is drying and the right tower is purging, purge air
flows from left to right through the first orifice, then the purge
pressure adjustment valve, past the pressure tap for the purge
pressure gauge, through the second and final orifice and into the
offline tower. The pressure in the purge circuit just before the final
orifice controls the purge flow rate. Because the purge pressure
tap lies between the purge pressure adjustment valve and the
orifice closest to the right hand tower, the purge pressure can
only be correctly read and adjusted when the purge flow is from
left to right. This only occurs when the right hand tower is actively
purging. IMPORTANT: Purge pressure adjustment must be
made while the RIGHT HAND TOWER AS SEEN FROM THE
FRONT OF THE UNIT is regenerating and the right hand tower
is actively purging (the purge valve associated with the right
tower is open and air is exhausting from its muffler). Due to
the symmetry of the design, identical orifices at opposite ends
and the bi-directional flow characteristics of the purge pressure
adjustment ball valve, purge flow will be similar when towers
switch and the purge flow is from the drying tower on the right
towards the regenerating tower on the left. Purge pressure as
indicated by the purge pressure gauge should be disregarded
during this half of the operating cycle.
• The purge pressure adjustment valve should never be fully closed.
Proper purge flow is required to regenerate and re-pressurize the
offline tower. Should the tower fail to re-pressurize, a switching
failure alarm will be initiated, and the cycle will be stopped before
tower switch over.
• After the purge pressure has been correctly set, the handle of the
purge pressure adjustment valve may be removed and stored to
prevent tampering with the setting.
9.1.4.2 Purge Rate Pressure – Models 4100 to 5400
• Refer to Table 9-4 for the proper purge rate pressure setting
corresponding to the conditions listed in Section 9.1.4.
NOTE: For units with the Level 2 Controller and the Automatic
Purge Saving System in the demand cycle mode use the ISO
Class 2 (10 min.) purge pressure settings only.
• Adjust purge rate valve until purge pressure gauge indicates
the required pressure. The purge pressure adjustment valve on
Models 4100 through 5400 is a globe valve located in the smaller
by-pass line of the upper piping in the front of the dryer. Refer to
Figure 4-4. IMPORTANT: Adjustment must be made while
either tower is purging (air exhausting from muffler).
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