ESD SYSTEMS SPI Ground Gard 3 Plus, Technical Bulletin

TB-5545 Page 3 of 4      

                  Revision May 2009

                                               © 2009 DESCO INDUSTRIES INC.

                       Employee Owned

ESD Systems.com • 432 Northboro Road Central • Marlboro, MA 01752 • (508) 485-7390 • Fax (508) 480-0257 • Website: 

ESDSystems.com

Installation

Remove the monitor from its packaging and inspect for 
any shipping damage.  Confi rm that the work surface is 1 
x 10E7 ohms or less and has a conductive layer such as 
Dual Layer Rubber, Dissipative 3-Layer Vinyl, or Mica-
stat® Dissipative Laminate with conductive buried layers.  
Included with each Multi-Mount Continuous Monitor 
should be:

2 

Mat Monitor Cords (black and green)

2 

Push and Clinch Snaps

 2 

Mounting 

screws

 1 

Velcro® 

Set

1 

120 VAC Power Adapter (

94338

 only)

 1 

Certifi cate of Calibration

I.   The Ground Gard 3 Plus may be mounted to a 
     convenient location using the included mounting
     screws or Velcro® set.  See Figure 3 for installation
     set-up.

II.  Install the Push and Clinch snaps 12-72 inches apart
     from each other on the work surface mat.  Make sure
     that they pierce and clinch the bottom side of the mat.

III. Snap both ground cords to the push and clinch snaps
     installed to the work surface mat.

IV. Route the black ground cord to the monitor’s green
     terminal block labeled MAT.

V.  Route the green ground cord to the monitor’s green
     terminal block labeled GND.

VI. Connect the power adapter to the monitor’s power
      jack labeled “24VAC” and the other end to a proper
     voltage source.

Figure 3.  Installation of the Ground Gard 3 Plus

Operation

When the Multi-Mount Continuous Monitor is installed to 
an ESD protective work surface and grounded via a pow-
er cord, the green WORKSURFACE GROUND LED and 
red OPERATOR GROUND LED should be illuminated.

• The work surface resistance is measured between the   
two snaps installed to the mat worksurface (See Figure 3).

TO USE THE CONTINUOUS MONITOR:

1. Plug a wrist strap cord, not attached to the wristband, 
into the monitored banana jack labeled OPR on the side 
of the unit (See Figure 2). This automatically activates 
the selected operator channel.  The red operator LED 
should illuminate. The monitor takes 6 seconds to acti-
vate its alarm circuitry when it is fi rst plugged in.

2. Remove the charges from your body by making con-
tact with a properly grounded ESD worksurface.  Snap 
the cord to the wristband, and fi t it snugly onto your 
wrist.  This should silence the audible alarm and cause 
the OPERATOR GROUND LED to switch from red to 
green. If this does not happen, examine the wrist cord for 
continuity or damage and your wrist band to ensure that 
it is securely fi t.  If you have dry skin, apply an approved 
dissipative hand lotion.  When leaving the area, the user 
can take the wrist cord along or attach it to the monitor 
parking snap. The audible alarm will shut off in approxi-
mately 6-8 seconds when operator wrist cord is removed 
from unit and will instantly shut off when the cord is at-
tached to the parking snap.

PARKING SNAP

The audible alarm is designed to alert both the operator 
and supervisor.  The parking snap feature allows the op-
erator to disconnect when leaving the work area without 
sounding the audible alarm.  It also provides a means 
for wrist cord storage (red OPERATOR GROUND LED 
will illuminate).  When the operator touches the parking 
snap, the audible alarm will disable for 6 seconds. The 
user can then disconnect the wrist cord from the wrist 
band and attach it to the parking snap for storage.  If the 
operator removes the wrist cord plug from the OPR ba-
nana jack, the audible alarm will sound for 6-8 seconds.

WORK SURFACE CHANNEL

The Ground Gard 3 Plus monitoring circuitry is suffi cient-
ly sensitive to detect extremely low current when used 
with a worksurface with a conductive layer.

Specifi cations: 

Test range of monitored circuit  500K - 10M ohms†
Operating Voltage
    

94338

                                      120 VAC, 50/60 Hz

94339

                                      220 VAC, 50/60 Hz

Work Surface Range                  10 Megohms (see Note)
Wrist strap open circuit voltage  1.2 volts peak to peak @
                                                   1-2 MicroAmps
Mat test open circuit voltage      5 to 7.5 volts
Response time to alarm             <50 ms
Operating Temperature              0 - 40°C
Size                                            3.86”L x 2.10”W x .910”H

† This cannot be verifi ed with standard DC test 
equipment. The continuous monitor is an impedance 
sensing device and the limits are determined by the 
magnitude and angle of the impedance.