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Single Wire Multifunction Wrist Strap
Monitor Operation and Maintenance
Figure 1. Item 50513 Single Wire Multifunction Wrist Strap
Monitor
Description
The Desco EMIT 50513 contains all the monitoring
functions required to ensure that the wrist straps,
worksurface, and ground connections of a workstation are
fully functional at all times.
The 50513 continuously monitors:
1. The operator wrist strap for changes in load, or open
circuit
2. The worksurface for resistance
3. Electrical ground (or earth ground) for continuity and low
resistance
Installation
Fasten the 50513 with the supplied hook-and-loop self
adhesive strip. The 50513 requires only 4 connections to
work properly: 1) electrical ground, 2) worksurface, 3) single
wire wrist strap, and 4) electrical power.
GROUND
The electrical ground connection is made through the cord
of the three-wire US/CSA approved AC adapter. Per the
ESD Association ANSI/ESD S20.20, electrical ground is
preferred.
If you are using earth ground, make the connection by
attaching a wire to a water pipe clamp or use an 8" to 12"
copper ground stake. A large number of workstations can
be connected to a single heavy gauge ground wire. Attach
the ground wire to the pin jack adapter on the back of the
unit labeled “GND”. Solder the wire directly to the banana
plug-to-pin jack adapter or use a banana plug on the
ground wire. This pin jack is internally connected to the
banana jack on the front of the unit marked “WRIST
STRAP/GUEST”. This jack may be used as an auxiliary
electrical ground connection point for another piece of
equipment, or as a plug-in point for a wrist strap by persons
visiting the workstation.
Make the worksurface monitoring connection by attaching
two wires to the worksurface. Use “snap” connectors or a
CK-1 contact kit with the two contact points positioned
approximately 1" or less apart. Attach one wire to the pin
jack adapter on the back of the unit labeled “BENCH” and
the other wire to system ground.
Complete the installation by plugging the UL/CSA approved
AC adapter DIN plug into the DIN jack on the rear panel
marked “POWER”, and the adapter into a grounded outlet.
Proper installation is indicated by a red “STRAP” LED, a
green “BENCH” LED, a green “GND” LED, and an
approximately 3 second activation on the audible alarm.
(NOTE: All three LEDs must be green in order to reset
the audible alarm circuit after an alarm condition.)
Wear the single wire wrist strap and plug the cord into the
front panel “WRIST STRAP MONITOR” jack. Observe that
all three green LEDs are on.
Operation
Ground Monitor:
The green “GND” indicator will illuminate when the total
resistance to ground measures less than 100 ohms. Ground
loop resistance greater than 100 ohms will produce a red
“GND” indicator and an audible alarm for approximately 3
seconds.
Check for proper operation by disconnecting the ground
wire from the “GND” terminal or by floating the ground pin
on the power adapter by way of a two-prong to three-prong
adapter (readily available in hardware stores). The “GND”
indicator should illuminate red and the alarm should sound
for approximately 3 seconds when either ground is
interrupted.
DESCO EMIT WEST
- 3651 Walnut Avenue, Chino, CA 91710 • (909) 627-8178 • Fax (909) 627-7449
DESCO EMIT EAST
- 90 Hudson Road, Canton, MA 02021-1407 • (781) 821-8370 • Fax (781) 575-0172 • Web Site: http://www.descoemit.com
Made in America
TECHNICAL BULLETIN TB-6511
© 2004 DESCO INDUSTRIES INC.
Employee Owned
