Desco EMIT 50680 Service manual

Operation
Set the fan speed switch on the rear of the unit to the LOW,
MED, or HI position. Higher airflow will result in faster
neutralization rates. Position the unit so that the maximum
airflow is directed at the items or area to be neutralized.
Turn the unit ON.
When the unit is first turned on, it conducts a self-test. The
audible alarm will sound and then the LED will cycle through
RED, YELLOW, and then GREEN. The LED will remain
GREEN during normal operation.
Balance Adjustment
The 50680/50681 is an auto-balancing unit. However,
tuning or manual adjustment can be accomplished by
inserting a small screwdriver or trimmer adjustment tool into
the balance adjustment hole located on the front of the unit.
To increase the output in a positive direction, turn the
potentiometer in a clockwise direction. Conversely, to
increase the output in a negative direction, turn the
potentiometer in a counter clockwise direction. Once the
desired balance point has been achieved, the alarm reset
button must be pressed to set the balance point.
Maintenance / Alarms
It the supply voltage drops from 110 Volts to below 85 Volts
or from 220 Volts to below 170 Volts, the unit will shut down,
the audible alarm will beep, and the LED will blink RED.
The unit will automatically reset when the minimum voltage
is restored.
Under normal conditions, the ionizer will attract dirt and dust
(especially on the emitter electrodes). To maintain optimum
neutralization efficiency and operation, cleaning should be
performed on a regular basis.
If the performance of the ionizer were to degrade because
of dirty or corroded points, the unit will enter a maintenance
condition. When the ionizer is in a maintenance condition,
the LED on the front of the unit will blink alternately
YELLOW and RED; the audible alarm will sound. If the
performance continues to degrade, the unit will enter
shutdown mode.
When the unit enters shutdown mode, ionization will be
stopped, the LED on the front of the unit will change to a
steady RED, and the audible alarm will sound continuously.
If the ionizer enters shutdown mode, it must be turned OFF
and then back ON to reset the unit.
Figure 1. Desco Emit Overhead Ionizer
Description
The Model 50680/50681 is a three fan, dual steady state
DC auto-balancing overhead ionizer. The unit is normally
hung from the ceiling above the area to be neutralized. The
ionizer's neutralization time will be best approximately 24" to
48" directly above the work surface and will increase as the
distance from the unit increases.
Installation
Remove the ionizer from the carton and inspect for
damage. Included with the unit should be:
1. Hanging kit
2. Power cord
3. Emitter point cleaner
The input voltage should be set to your specification prior to
shipping. It can be verified or reset by removing the top of
the case by disengaging the 4 screws. NOTE: The AC
power cord MUST always be disconnected before the unit
is disassembled.
Input voltage is selected with the two internal jumpers on
JH1. For 110 volt jumper setting, a jumper must be in place
shorting pin 1 to 2 and another shorting pin 3 to 4. For 220
volt jumper setting, a single jumper must be in place
shorting pin 2 to 3 only.
Before installing the unit, verify that the AC outlet is properly
connected to earth ground. The unit must have a good
earth ground to maintain proper balance. Install the unit in
the desired location, making sure that the airflow will not be
restricted. Be sure the ON/OFF switch, located on the rear
of the unit, is in the "OFF" position. Plug the power cord
into the unit and then into the appropriate AC power source.
Status of the unit can be monitored remotely via the RS485
data ports. Please contact the factory for the necessary
polling utility.
TB-6545 11//05 Page 1 of 5
Overhead Ionizer
Installation, Operation, and Maintenance Made in America
TECHNICAL BULLETIN TB-6545
© 2005 DESCO INDUSTRIES INC.
Employee Owned
DESCO EMIT WEST - 3651 Walnut Avenue, Chino, CA 91710 • [phone] • Fax [phone]
DESCO EMIT EAST - 90 Hudson Road, Canton, MA 02021-1407 • [phone] • Fax [phone] • DescoEMIT.com

TB-6545 Page 2 of 2
NOTE: The AC power cord MUST be disconnected before
the unit is disassembled for maintenance. The emitter
electrodes should be cleaned using the alcohol cleaners
included or a swab wet with Isopropyl alcohol. First, turn
the unit OFF and unplug the power cord. Then remove the
back cover by disengaging the 4 screws on back. After
cleaning the emitter electrodes, reattach the back cover
using the 4 screws. Plug in the power cord and turn the
unit back ON.
The emitter electrodes should not require replacement
during the life of the unit with normal handling.
Replacement emitter electrodes can be ordered if
necessary.
Best practice would be to verify the balance of the unit with
a charge plate monitor after cleaning.
Neutralization (Decay) Times
The comparative efficiency of benchtop ionizers is
determined by a standard test published by the ESD
Association: Standard S3.1. Typical positive and negative
decay times (from 1000 volts to 100 volts) measured using
this standard are shown below. The performance of the
ionizer was measured with the unit positioned as shown,
with the fan speed on high, and without a filter.
Figure 2. Neutralization (Decay) Times
Note: Reference ESD STM 3.1-2000. The distance from
the 50680/50681 to the charge plate is 18". (Readings are
typical and taken at maximum fan speed.)
Specifications
Air Flow
Three speed fans (125fpm -250fpm; 50-100cfm).
Balance
±10 volt, typical; ±20 volts maximum.
(Temperature range: 65°F to 80°F, R.H.: 15% to 65%)
Chassis
White powder coated steel housing.
Dimensions
3.5" height x 6.5" width x 37" length.
Emitter Points
.050" diameter pure tungsten for improved mechanical
strength and ionization stability.
Fuse
400mA slow blow.
High Voltage Power Supply
5.5 KV DC nominal.
Input Power
AC line power, internally selectable for 110/115 VAC-
50/60Hz or 220/230 VAC-50/60Hz.
Ion Emission
Steady state DC with sense feedback.
Mounting
Hanging apparatus attached to ceiling.
Ozone
Less than 0.05ppm
Weight
10 pounds
NOTE: Unauthorized servicing or modifications to your
ionizer will void the product warranty and may create
dangerous conditions. Servicing should be performed only
at the factory, or by a Desco EMIT approved technician.
© 2005 DESCO INDUSTRIES INC.
Employee Owned
DESCO EMIT WEST - 3651 Walnut Avenue, Chino, CA 91710 • [phone] • Fax [phone]
DESCO EMIT EAST - 90 Hudson Road, Canton, MA 02021-1407 • [phone] • Fax [phone] • DescoEMIT.com
Limited Warranty
Desco EMIT expressly warrants that for a period of one (1) year
from the date of purchase, Desco Emit Overhead Ionizers will be
free of defects in material (parts) and workmanship (labor). Within
the warranty period, a unit will be tested, repaired, or replaced at
our option, free of charge. Call our Customer Service Department
at 909-627-8178 (Chino, CA) or 781- 821-8370 (Canton, MA) for a
Return Material Authorization (RMA) and proper shipping instructions
and address. Include a copy of your original packing slip, invoice,
or other proof of purchase date. Any unit under warranty should be
shipped prepaid to the Desco EMIT factory. Warranty repairs will
take approximately two weeks.
If your unit is out of warranty, call our Customer Service
Department at 909-627-8178 (Chino, CA) or 01892 665313
(Crowborough, U.K.) for a Return Material Authorization (RMA) and
proper shipping instructions and address. Desco EMIT will quote
repair charges necessary to bring your unit up to factory standards.
Warranty Exclusions
THE FOREGOING EXPRESS WARRANTY IS MADE IN LIEU OF
ALL OTHER PRODUCT WARRANTIES, EXPRESSED AND
IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR A
PARTICULAR PURPOSE WHICH ARE SPECIFICALLY
DISCLAIMED. The express warranty will not apply to defects or
damage due to accidents, neglect, misuse, alterations, operator
error, or failure to properly maintain, clean or repair products.
Limit of Liability
In no event will Desco EMIT or any seller be responsible or liable
for any injury, loss or damage, direct or consequential, arising out
of the use of or the inability to use the product. Before using,
users shall determine the suitability of the product for their intended
use, and users assume all risk and liability whatsoever in
connection therewith.