EMIT 50664 Installation, Operation And Maintenance Manual

TECHNICAL BULLETIN TB-6534
Overhead Zero Volt Ionizer
Installation, Operation and Maintenance
Figure 1. EMIT Overhead Zero Volt Ionizer, 2-Fan
Figure 2. EMIT Overhead Zero Volt Ionizer, 3-Fan

Description

The patented* EMIT Overhead Zero Volt Ionizer (ZVI) is
a steady-state DC auto-balancing ionizer with integrated
closed-loop feedback. It combines the effectiveness
of steady-state DC ionization with ease of adjustability,
communication capability and the flexibility of a
microcontroller-based design to produce a versatile and
stable ionization system. Its fans produce extended
ionization coverage and are ideal for areas where bench
space is limited.
The Overhead Zero Volt Ionizer utilizes Steady State DC
ionization. Steady State DC systems consist of separate
negative and positive ion emitters connected by a pair of
high-voltage cables to their respective high-voltage power
supplies. The spacing between emitters varies depending on
the design, and DC power is constantly applied to the emitter
points. The ionizer utilizes feedback from the internal sensor
grill to continuously adjust the output to maintain balance.
"Necessary non-conductors in the environment cannot lose
their electrostatic charge by attachment to ground.
Ionization systems provide neutralization of charges on
these necessary non-conductive items (circuit board
materials and some device packages are examples of
necessary non-conductors). Assessment of the ESD
hazard created by electrostatic charges on the necessary
TB-6534 Page 1 of 8 November 2012
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nonconductors in the work place is required to ensure that
appropriate actions are implemented, commensurate with
risk to ESDS [ESD sensitive] items". (ANSI/ESD S20.20-
2007 Foreword)
"In order to mitigate field-induced CDM [Charged Device
Model] damage, the ESD program shall include a plan for
the handling of process-required insulators. If the field
exceeds 2,000 volts/inch, steps shall be taken to either: A)
Separate the insulator from the ESD-sensitive device by a
distance of 30 cm (12 inches); or B) Use ionization or other
charge mitigating techniques to neutralize the charge."
(ANSI/ESD S20.20-2007 section 8.3)
"The primary method of static charge control is direct
connection to ground for conductors, static dissipative
materials, and personnel. A complete static control program
must also deal with isolated conductors that cannot be
grounded, insulating materials (e.g., most common plastics),
and moving personnel who cannot use wrist or heel straps
or ESD control flooring and footwear.
Air ionization is not a replacement for grounding methods.
It is one component of a complete static control program.
Ionizers are used when it is not possible to properly ground
everything and as backup to other static control methods.
In clean rooms, air ionization may be one of the few
methods of static control available." (ESD Handbook ESD
TR20.20 Ionization, section 5.3.6.1)
"All ionization devices will require periodic maintenance for
proper operation. Maintenance intervals for ionizers vary
widely depending on the type of ionization equipment and
use environment. Critical clean room uses will generally
require more frequent attention. It is important to set-up a
routine schedule for ionizer service. Routine service is
typically required to meet quality audit requirements." (ESD
Handbook ESD TR20.20 section 5.3.6.7 Maintenance /
Cleaning)
EMIT ionizers meet the ANSI/ESD S20.20 minimum
recommended technical requirement range of less than
+/- 50 volts offset voltage balance tested in accordance
with ANSI/ESD STM3.1. All EMIT Overhead Ionizers
greatly exceed the requirement providing ±5 to ±25 volt
auto-balancing.
The Overhead Zero Volt Ionizer is available in four models:
Item Fans Voltage
50664 2 120 VAC
50665 3 120 VAC
50671 2 220 VAC
50672 3 220 VAC
DescoEMIT.com
Made in the
United States of America
CSA
Approved Power Cord
Yes North America
Yes North America
No None
No None
*US Patent 6,205,408
© 2012 DESCO INDUSTRIES, INC.
Employee Owned