SCS 770048 Owner's manual

TB-9112 Page 1 of 3 © 2021 DESCO INDUSTRIES INC
Employee Owned
June 2021
Description
The SCS Common Point Ground Monitor confirms the
integrity of the resistance path from the common ground
point to electrical ground. It is designed in accordance
with ESD TR 12-01 to “monitoring equipment ground
connections.”
When the Common Point Ground Monitor is plugged
into an electrical receptacle, its green LEDs illuminate
when both the power outlet's wiring is correct and
the path-to-equipment ground via the equipment
grounding conductor is intact. The monitor provides
12 verified ground points when in a PASS condition.
The monitor's red LEDs illuminate and audible buzzer
sounds when either the outlet’s wiring is incorrect or the
path-to-equipment ground is defective. Mounting tabs
make it suitable to install in workbench or equipment
settings.
The outlet ground line is tested by measuring voltage
between it and the neutral line. It is normal to have
a few volts of AC induced on the neutral line. If the
Common Point Ground Monitor measures only a few
volts, the ground line to neutral impedance is low and
the ground line would make a suitable ESD ground
point. If the monitor measures more than just a few volts
between ground and neutral, this indicates either that
they are not referenced to each other or that the outlet
and associated wiring should be checked for loose
connections. In this case, the Common Point Ground
Monitor will sound a warning alarm and display a red
FAIL indication and should not be used for an ESD
grounding point until corrected.
Use the Common Point Ground Monitor to fulfill the
ANSI/ESD S6.1 section 6.3.1 requirement. “The hot,
neutral and equipment grounding conductor shall
be verified to be in the proper wiring orientation in
accordance with the National Electric Code (NFPA
70®).”
The Common Point Ground Monitor is available as the
following item numbers:
Item Description
770048 Common Point Ground Monitor, with North
America Power Cord
770049 Common Point Ground Monitor, with UK
Power Cord
Packaging
1 Common Point Ground Monitor
6 Socket Head Screws, 10-32 x 1/4"
6 Split Washers, #10
2 Pan-Head Screws, #6 x 3/8"
1 Dual Lock Fastener Set, 2" Length
1 Hex Key, 5/32"
1 Power Cord, 6' Length
1 CerticateofCalibration
Common Point Ground Monitor
Installation, Operation and Maintenance Made in the
United States of America
USER GUIDE TB-9112
Figure 1. SCS Common Point Ground Monitor

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Employee Owned
A. Status LEDs: Illuminates green when the AC outlet
is properly wired and its path to equipment ground via
the equipment ground conductor is intact. Illuminates
red and audible alarm sounds when the AC outlet is not
properly wired and its path to equipment ground via the
equipment ground conductor is broken.
B. Ground Hub: Brass machined hex block with six
banana jacks and six screws for #8 ring terminals.
Provides grounding point for wrist straps, ground cords,
and tools.
C. Power Inlet: Connect the included power cord here.
Features and Components Installation
1. Remove the Common Point Ground Monitor and its
power cord from their carton.
2. Determine the mounting location of the Common
Point Ground Monitor. Its LEDs should be visible
to the operator. Secure the Common Point Ground
Monitor to a surface using its mounting tabs and the
included pan head screws or dual lock fasteners.
3. Connect the power cord to the power inlet located
on the right-side of the Common Point Ground
Monitor. Connect the opposite end to an appropriate
AC outlet.
4. The status LEDs will illuminate green if the AC
outlet is wired correctly and its path-to-equipment
ground via the equipment grounding conductor is
intact. The status LEDs will illuminate red, and the
audible buzzer will sound otherwise.
Figure 2. Common Point Ground Monitor features and
components
A
A
B
A
C
Figure 3. Installing the Common Point Ground Monitor at
the end of a row of workbenches

TB-9112 Page 3 of 3 © 2021 DESCO INDUSTRIES INC
Employee Owned
Calibration
Frequency of recalibration should be based on the
critical nature of those ESD sensitive items handled and
the risk of failure for the ESD protective equipment and
materials. In general, SCS recommends that calibration
be performed annually.
NOTE: The following procedure should only be done by
someone familiar with voltage hazards. This procedure
will work for 220 VAC as long as the neutral and ground
are referenced. 220 VAC produced with out-of-phase
110VAC-Ground-110VAC will produce a FAIL result.
1. Disconnect the power cord from the electrical outlet
and connect it to a 3-prong to 2-prong adapter to
isolate its ground pin.
2. Connect the 3-prong to 2-prong adapter to an
appropriate AC outlet to power the Common Point
Ground Monitor.
3. Connect a 5 kilohm resistor (5% tolerance) between
the supply ground and power cord's ground pin.
The status LEDs should illuminate green until the
resistor is removed. This test validates the PASS
point for the neutral-to-ground resistance.
4. Connect a 12.5 kilohm resistor (5% tolerance)
between the supply ground and power cord's
ground pin. The status LEDs should illuminate red
and audible buzzer should sound. This test validates
the FAIL point for the neutral-to-ground resistance.
Limited Warranty, Warranty Exclusions, Limit
of Liability and RMA Request Instructions
See the SCS Warranty -
StaticControl.com/Limited-Warranty.aspx
Operation
Use the banana jacks on the ground hub to connect
banana plugs to ground. Use the 6 included socket
head screws and split washers to secure ground wires
with ring terminals.
Figure 4. Using the Common Point Ground Monitor
Specifications
Input Voltage and
Frequency
Power Input:
100-240 VAC, 50/60 Hz
Power Cord Length:
6 ft. (1.8 m)
Operating Temperature 50 to 95° F (10 to 35° C)
Environmental
Requirements
Indoor use only at altitudes
less than 6500 ft. (2 km)
Maximum relative humidity
of 80% up to 85° F (30° C)
decreasing linearly to 50% @
85° F (30° C)
Dimensions 4.38" L x 2.47" W x 1.00" H
(111 mm x 63 mm x 25 mm)
Weight 0.35 lbs. (0.16 kg)
Equipment Ground
Conductor Resistance
Limit
10 kilohms (nominal)
Country of Origin United States of America