CRITICAL ENVIRONMENT (C/E)
SERIES OVERHEAD IONIZER
OWNER’S MANUAL
Made in America
DESCO WEST
- 3651 Walnut Avenue, Chino, CA 91710 • (909) 627-8178 • Fax (909) 627-7449
DESCO EAST
- 90 Hudson Road, Canton, MA 02021 • (781) 821-8370 • Fax (781) 575-0172 • Web Site: http://www.desco.com
TB-2087
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Description
Ionizers are useful in preventing electrostatic charge
generation, ElectroStatic Discharge, ElectroStatic
Attraction, as well as preventing equipment latch-up
and safety related shock. ANSI/ESD S20.20 Paragraph
6.2.3.1 Protected Areas Requirement states:
"Ionization or other charge mitigating techniques shall
be used at the workstation to neutralize electrostatic
fields on all process essential insulators if the
electrostatic field is considered a threat." Ionization is
used to neutralize charges on process necessary
insulators and isolated semiconductors. Some
examples of process necessary insulators are: the PC
board itself, plastic test stands, plastic housing where a
PCB may be mounted, as well as computer monitor
screens and regular cleaning wipes. Examples of
floating or isolated conductors are: loaded PCB
mounted in a stand where the pins are not contacting
the dissipative workstation. Ionization is not effective
on items that have large capacitance, like people and
carts; however, ionizers should be considered as a
method for charge neutralization in cases where
grounding cannot be achieved.
Air ionization can neutralize the static charge on
insulated and isolated objects by producing separate
charges in the molecules of the gases of the
surrounding air. When an electrostatic charge is
present on objects in the work environment, it will be
neutralized by attracting opposite polarity charges from
the ionized air. Note that ionization systems should
not be used as a primary means of charge control on
conductors or people. (Reference: IEC 61340-5-2:1
paragraph 5.2.9).
The Desco Critical Environment overhead ionizers are
NIST calibrated and are available in four models:
IONIZER SELECTION
ANSI/ESD S20.20 paragraph 6.1.1.2. ESD Control
Program Plan Guidance states: "The Plan should
include a listing of the specific type of ESD protective
materials and equipment used in the Program." When
selecting an ionizer life cycle costs should be
considered including: equipment cost; installation cost;
and operation and maintenance cost.
The C/E series offers many design improvements,
most notably, our patented "Emitter Cassette" (see
figure 1). While other manufacturers attempt to
simplify or automate the cleaning of the emitter pins,
what remains is one major flaw in the process - unless
the ionizer is removed to another area, the
contamination ends up on the workstation and on any
product that happens to be nearby. The C/E series
solves this problem. When the emitters need to be
cleaned, the cassettes are easily removed from the
unit and taken to another area to be cleaned. This
takes the dirt away from the workstation and product.
To eliminate downtime, a spare set of clean emitter
cassettes can be dropped in. The others can be
cleaned when convenient. This concept is so unique,
that we have been awarded a patent* on it.
Model
Description
60478
60479
60481
60482
60480
C/E OH Ionizer 24"
C/E OH Ionizer 48"
C/E OH Ionizer 24"
C/E OH Ionizer 48"
Replacement Emitter
Cassette
Voltage
120V
120V
220V
220V
N/A
Figure 1. Removable emitter cassette
Features
• Removable emitter cassettes allow you to minimize
contamination of the work area.
• Closed-loop feedback electronic balance system
continuously monitors output for optimal
performance.
• I/O port allows auto-calibration and remote status
monitoring.
• Sealed plenum chamber around each fan minimizes
contamination.
The 60478 and 60481 are 24" long units with 2 fans,
and the 60479 and 60482 are 48" long units with 4
fans. All models have the same features permitting
the user to select the best size for the application.
Since our introduction of the first overhead ionizer in
the market, we have continued to enhance our
offerings with the most advanced features available.
*U.S. Patent #6,137,670
DESCO WEST
- 3651 Walnut Avenue, Chino, CA 91710 • (909) 627-8178 • Fax (909) 627-7449
DESCO EAST
- 90 Hudson Road, Canton, MA 02021 • (781) 821-8370 • Fax (781) 575-0172 • Web Site: http://www.desco.com
TB-2087
Page 2 of 8
• Non-volatile adjustments for balance and fan speed
are maintained in the absence of power.
• Lockout key with distinctive front panel indicator
prevents unauthorized adjustment.
• Balance is individually adjustable at each fan zone.
• Flashing front panel signal indicates when cleaning
is needed.
• IEC input and output connectors allow daisy-chaining
of a second unit.
• Stainless steel and powder-coated aluminum
construction for durability and long life.
should be taken to insure that the mounting is secure
and capable of supporting the weight of the unit. The
power cord should be supported as well to provide
protection against any hazard to the operator.
"S" hooks are provided with each unit to facilitate
mounting using the chain suspension method. The
ideal mounting height is 24" above the work surface,
although the ionizer may be located slightly higher or
lower if required. For maximum performance, care
should be taken to insure that the intake grills for the
fans are not obstructed.
Turn the power key switch to the "OFF" position. Plug
the IEC end of the cord into the ionizer and the other
end into a properly wired outlet. We recommend that
the outlet used by the ionizer be tested before use and
periodically checked for correct wiring and a good solid
ground. The C/E ionizer depends on a good ground
for proper balancing.
Safety interlock switches are provided internally on
each emitter cassette. This ensures that power is
cut off in the event that any cassette is removed or
not fully installed.
The grills below each fan function as sensors and
feedback a signal to the balance circuitry. Therefore, it
is important not to hang or attach anything to the fan
grills.
Specifications
Input Power:
120VAC
120VAC
220VAC
220VAC
250mA
400mA
250mA
400mA
(24"
(48"
(24"
(48"
model)
model)
model)
model)
IEC Outlet:
Fuse:
Air Flow:
Emitters:
Ionization Type:
Balance:
Weight:
Size:
Mounting:
Allows a second unit to be
daisy-chained
5x20mm 3 amp time lag
80-170 CFM (24" model)
160-340 CFM (48" model)
100% Tungsten, replaceable
Steady-state DC
0+/-10 volts at set-up at 24"
above charged plate analyzer
6.2 lbs. (24" model)
11.1 lbs. (48" model)
Controls and Functions
Figure 2. Control Panel
2" x 6" x 24"
2" x 6" x 48"
(2) ¼" mounting holes each end
• The
CONTROL PANEL
is located on the right hand
end of the ionizer. It provides controls for fan speed,
balance, and a key switch to prevent unauthorized
adjustment of the controls. Also located on the
control panel is an I/O port that may be used for auto
calibration (with optional Auto Calibration Unit, item
number 60491). It also is used to provide output
signals to allow remote monitoring of ionizer status.
Installation
The Desco C/E ionizer is designed to mount above the
work area, providing even coverage without using
valuable work surface area. Mounting is a matter of
personal preference, and may be accomplished with
brackets attached to a shelf, or the unit may be
suspended by chain. Whatever method is used, care
DESCO WEST
- 3651 Walnut Avenue, Chino, CA 91710 • (909) 627-8178 • Fax (909) 627-7449
DESCO EAST
- 90 Hudson Road, Canton, MA 02021 • (781) 821-8370 • Fax (781) 575-0172 • Web Site: http://www.desco.com
TB-2087
Page 3 of 8
•
OFF/SET/LOCK
key switch - this switch controls the
power to the ionizer. When the SET position is
selected, it allows the balance and fan speed to be
adjusted. When the LOCK position is selected, a
LOCK indicator is illuminated on the front panel of
the ionizer. In this position, the balance and fan
speed controls are disabled and the key is
removable. In the OFF position, power is shut off to
the ionizer and the key is removable.
•
FAN
speed adjustment switches are used to set
the fan speed to the desired level that provides
the best performance while minimizing operator
discomfort. With the key switch in the SET
position, pressing and holding the + symbol will
increase fan speed, and the - symbol will decrease
fan speed. Relative fan speed is displayed on the
front panel indicator.
•
BAL
controls are used to adjust the balance of
the ionizer and are used in conjunction with a
charged plate analyzer. Pressing the “+” symbol will
shift the balance offset positive, while pressing the “-”
symbol will shift it negative. Adjustment should be
made with a charged plate analyzer located 24"
directly under the ionizer. The BAL controls, like the
FAN speed, are only adjustable when the key switch
is in the SET position.
•
I/O PORT
serves a dual purpose. It accepts
signals from the optional Auto Calibration Unit and
automatically calibrates the ionizer when the key
switch is in the SET position. It also outputs ionizer
status signals that can be useful for remote
monitoring.
•
IEC INPUT CONNECTOR
based on the
International IEC 60320 Standard, allows the power
to be disconnected at the ionizer and provides a
fuse drawer for a 5mmx20mm fuse. The fuse drawer
may be opened when the cordset is removed. In
addition, an IEC Outlet on the opposite end of the
ionizer can supply power for a charged plate
analyzer, or for daisy-chaining a second unit.
Front Panel Display and
Controls
See figure 3.
System Status
is the information center on the front of
the ionizer. From it, the operator can easily check the
operational status of the ionizer.
•
PWR
- this indicator will normally be green when the
ionizer is operating correctly. When the autobalance
circuit can no longer adjust for dirty emitter pins, this
indicator will turn red and begin to flash. It is normal
for it to flash for a few seconds each time the ionizer
is turned on. This indicator will be on when the key
switch is either in the "SET" or "LOCK" position.
•
LOCK
- when the key switch on the end of the
ionizer is set to lock, this indicator will display a
distinctive blue light. This makes it readily apparent
that the ionizer has its settings locked, preventing
unauthorized adjustment.
•
AIRFLOW
- this display indicates relative airflow
output from the fans. If the key switch is in the
"SET" position and the "+" or "-" button are pressed
and held, the fan speed will increase or decrease
with a corresponding change in the AIRFLOW
display. As fan speed is increased, the display will
move to the right.
• MINOR ADJUSTMENTS ACCESS
(see figure 4).
Each fan zone may be balanced separately. The
adjustments are designed for minor corrections to
balance one fan to another. Overall balance
adjustments should be done with the "BAL" switches
on the end panel.
•
VR6, VR5, VR2, and VR1
- are the zone balance
adjustments for the zones 1 through 4 respectively.
Zone 1 is closest to the right end. 24" models will
only have VR6 and VR5 adjustments. These
adjustments are covered in the section titled
"Calibration Instructions".
Figure 3. Front panel display and controls
DESCO WEST
- 3651 Walnut Avenue, Chino, CA 91710 • (909) 627-8178 • Fax (909) 627-7449
DESCO EAST
- 90 Hudson Road, Canton, MA 02021 • (781) 821-8370 • Fax (781) 575-0172 • Web Site: http://www.desco.com
TB-2087
Page 4 of 8
•
VR3 and VR4
- are adjustments to center the alarm
and to change the alarm sensitivity. These
adjustments are covered in the section titled
"Calibration Instructions".
•
ALARM SWITCH
- this switch provides an audible
alarm to supplement the flashing red PWR light
when the unit needs cleaning.
Maintenance
"As with all ionizers, periodic maintenance will be
needed to provide optimum performance." (Reference:
IEC 61340-5-2:1paragraph 5.2.9).
The frequency of monitoring ionizers really depends on
how and where they are used. Since the majority of
them use a fan to transport the ions to the working
area, the cleanliness of the air directly affects their
performance over time and how often the emitters
should be cleaned.
EIA-625 recommends checking ionizers every 6
months, but this may not be suitable for many
programs particularly since an out-of-balance may
exist for months before it is checked again. ANSI/ESD
S20.20 paragraph 6.1.3.1 Compliance Verification Plan
Requirement states: "Test equipment shall be selected
to make measurements of appropriate properties of the
technical requirements that are incorporated into the
ESD program plan." And paragraph 6.1.3.2.
Compliance Verification Plan Guidance states: "In
addition to internal audits, external audits
(Organization and supplier of ESDS items) should be
performed to ensure compliance with planned
requirements. Verifications should include routine
checks of the Technical Requirements in the Plan.
The frequency of verification checks should be based
on the control item usage, its durability and associated
risk of failure."
Under normal conditions the ionizer will attract dirt and
dust (especially on the emitter and fan guards). To
maintain optimum performance, cleaning must be done
on a regular basis. The electrodes should be cleaned
at least every 6 months. However, more frequent
cleaning may be required if used in environments with
more contaminants.
This was a major factor in the design process of the
C/E ionizer. The Replacement Emitter Cassette can
be removed to another area, and the emitters are then
very accessible. Although we could not eliminate the
maintenance, we have made it far easier and to clean
than ever before.
• Turn the key switch to the OFF position.
• Grasp the Replaceable Emitter Cassette ejector
levers at the center and pivot outward about 90
degrees.
• Grasping the right and left corners, pull the
Replaceable Emitter Cassette straight out of the
ionizer.
Operation
After the unit is mounted securely and connected to a
properly wired outlet, turn the key switch to the set
position. The performance of the ionizer is directly
related to the airflow on the area to be protected.
Generally, try to use the highest setting possible
without disturbing the operator or the work in process.
After allowing the unit to run for several minutes, a
charged plate analyzer can be used to check the
balance and performance. We recommend doing this
at the time of the initial installation, so that data can be
collected and saved for future reference. Place the
charged plate monitor directly under each fan and
record the float (balance) voltage. If all fans are offset
slightly in the same direction, the (+) or (-) BAL
buttons can be used to correct the offset. If the
balance varies from a positive offset to a negative
offset between fans, the individual fan zone controls
can be touched up slightly as required.
It is not uncommon to find differences between ionizers
from bench to bench or even between fans on ionizers
during initial setup. This is often caused by the
presence of objects on or around the bench. Large
metal objects nearby or machines or equipment on the
bench will often cause a shift in the offset voltage at
that area. The individual zone controls of the C/E
ionizers allow this to be compensated for during initial
setup.
After balance offsets have been checked, the decay
performance of each fan should be measured and
recorded. This information will be useful to establish a
maintenance schedule. When decay times begin to
increase significantly, or if the red PWR light begins to
flash, emitter cleaning is usually indicated. By
recording the time intervals between the first few
cleanings, a maintenance schedule can be developed.
After initial setup and testing has been done, the key
switch can be set to the LOCK position and normal
workstation use resumed.
If the ionizer is used in a manner not specified by
the manufacturer, the protection provided by the
ionizer may be impaired.
DESCO WEST
- 3651 Walnut Avenue, Chino, CA 91710 • (909) 627-8178 • Fax (909) 627-7449
DESCO EAST
- 90 Hudson Road, Canton, MA 02021 • (781) 821-8370 • Fax (781) 575-0172 • Web Site: http://www.desco.com
TB-2087
Page 5 of 8
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