Desco 的 SPI-20686 规格书

规格书反馈/错误

-E$D SYSTEMScom

TB-5545 Page 1 of 4 Revision May 2009

Employee Owned

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

SPI Ground Gard 5 / 5.5

Operation, Installation, and Maintenance

TECHNICAL BULLETIN TB-20686

Made in the

United States of America

Figure 1. SPI Ground Gard items SPI-20686 and 94391.

Description

The SPI-20686 and 94391 are wrist strap and ground

monitoring devices for the electronics work station. It is

designed to constantly monitor two single wire wrist

straps using a Remote Operator Module for each user.

These units provide continuous monitoring of:

• One or two users wearing a wrist strap

• Ground (Verification between electrical and ESD

ground)

Leading companies use continuous monitors as a cost

effective component in satisfying the paragraph 6.1.3

Complicance Verification Plan requirements of ANSI/

ESD S20.20. The SPI-20686 and 94391 Continuous

Monitors provide continuous monitoring of two operators

and also functions to ensure connection to ground. If the

monitor, using capacitance technology, detects improper

grounding of the operator, the monitor will issue an

audible alarm along with an illuminated red LED to notify

the user of a problem.

Many customers are eliminating periodic testing and are

utilizing continuous monitoring to better ensure that their

products were manufactured in an ESD controlled

environment. Continuous monitoring is superior to

periodic testing. “While effective at the time of testing,

wrist strap checker use is periodic. The failure of a wrist

strap between checks may expose products to

damage from electrostatic charge. If the wrist strap

system is checked at the beginning of a shift and

subsequently fails, then an entire shift’s work could be

suspect.” (ESD TR 12-1 Section 1.0 Survey of Constant

Monitors for Wrist Straps)

Continuous Monitors eliminate the need for users to test

wrist straps and log the results; by their function, these

monitors satisfy the ISO 9000 and ANSI/ESD S20.20

Paragraph 6.2.2.2 test logging requirements. Per ESD-

S1.1 paragraph 6.1.3 Frequency of Functional Testing

“Daily (Wrist Strap) testing may be omitted if constant

monitoring is used.”

“Because wrist straps have a finite life, it is important to

develop a test frequency that will guarantee integrity of

the system. Typical test programs recommend that wrist

straps that are used daily should be tested daily.

However, if the products that are being produced are

of such value that knowledge of a continuous, reliable

ground is needed, and then continuous monitoring

should be considered or even required.” (ESD Handbook

TR 20.20 section 5.3.2.4.4)

The SPI-20686 and 94391 will alarm if preset values are

exceeded for capacitance, high resist and ground loss

conditions. The grounding system is redundant and will

still provide a limited grounding even if the utility ground

is lost and the system is in an alarm state.

Capacitance Type Continuous Monitors

“These types of monitors are used with a single wire

(single conductor) wrist strap. Monitors in this category

operate by “sensing” body capacitance. For capaci-

tance monitors, an AC voltage is applied to the wrist

strap through the single conductor ground cord. Due to

capacitive coupling of the person to ground based on the

surroundings, the monitor will indicate either good or bad

depending on the manual adjustment or preset

tolerance. Since a capacitor or capacitive network

responds like a resistor to an AC current, the single

conductor wrist strap monitor only provides an estimate

of the wrist strap wearer’s apparent resistance.”

(ESD Handbook TR 20.20 section 5.3.9.2 Types of

Continuous Monitors)

Packaging

Item SPI-20686

1 Ground Gard 5.5 Monitor

2 94340 Remote Operator Modules

2 10 Foot Phone Cords

1 12 Foot Ground Cord

1 Velcro® Set

4 Screws

1 Power Adapter - 3 Prong, 12 Volts

Item 94391

1 Groud Gard 5 Monitor

2 94340 Remote Operator Modules

1 Power Adapter - 2 Prong, 12 Volts

2 Remote Operator Cables

1 Black Ground Cord

1 Green ground Cord

2 Velcro® Strips

4 Screws

1 Certificate of Calibration

SPI-20686 94391

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

Employee Owned

TB-5545 Page 2 of 4 Revision May 2009

Employee Owned

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

Installation

1. SPI-20686 and 94391 Monitor Head:

The SPI-20686 and 94391 Monitors are designed to

maximize valuable work area and should be mounted at

eye level above the workstation, either on a post or shelf

support. A double-sided adhesive Velcro® attachment is

provided to hold the lightweight head in place.

2. GROUND CONNECTION:

The green wire extending from the monitor must be

attached to a facility ground.

Caution: The total amount of resistance through all

monitored parts should not exceed 10.0 megohms

total.

3. REMOTE OPERATOR MODULES:

The remote operator modules can be

mounted at the front of the work

surface, usually under the tabletop and

flush with the front edge. Two screws

for each unit are provided for mounting.

Connect each remote to the monitor unit using the

telephone cable with RJ11 connectors.

4. POWER UP TEST

After installing the Monitor , remote units, and making the

necessary connections without the wrist straps

connected, the unit should POWER UP with the wrist

strap LED’s OFF and the audible alarm SILENT. If you

have no response to power or a red LED, check AC

outlet for proper ground or refer to trouble shooting

section.

PARK SNAP

The audible alarm is designed to alert both operator and

supervisor. The Park Snap feature provides a means

for an operator to disconnect when normally leaving the

work area, without the audible alarm sounding, and it

provides a means of wrist cord storage. You may also

disconnect the coil cord by unplugging the banana plug

from the Remote Module. Both a 7mm and 4mm Park

Snap is provided on each module.

Remote Module Description

Inside both remote modules are infrared sensors that

react to the insertion of a wrist strap wire with a banana

plug. When the banana plug is inserted, the base unit is

activated for that remote module. The Monitor LED for

the left or right wrist strap will light showing the condition

of that strap. If correct, the LED should be GREEN.

Should the wrist strap fail, be worn incorrectly or

removed by the operator, the red indicator will flash,

calling attention to a problem. Should the ground

connection be lost, the red light and alarm will be

activated. The monitors are continuous and even a

momentary break will cause alarms. The remote

modules are set at the factory to allow for sensitivity of

the “average” human body model.

Calibration Procedure Using 94373

Tester

Testing the Remote Modules

Refer to Figure 2 to see the connection setup for the

94373 tester to the SPI-20686 and Figure 3 for the

94391 monitor. Make sure that the switch located on the

face of the tester is toggled to LEFT WS / RIGHT WS. If

connected properly, all three LEDs on the monitor should

be illuminated green.

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

Employee Owned

Figure 2. Connecting the SPI-20686 to the 94373 Tester.

SPI-20686

Remote Remote

94373

Figure 3. Connecting the 94391 to the 94373 Tester.

94391

Remote Remote

94373

TB-5545 Page 3 of 4 Revision May 2009

Employee Owned

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

To test the resistance of the left remote module, press

the black button labeled LEFT WS on the tester. If the

remote module is properly calibrated, the monitor’s

audible alarm will sound and the LEFT WRIST STRAP

LED will illuminate red. If the LED remains green, locate

the trim pot underneath the respective remote module.

Hold down the tester’s LEFT WS button and carefully

adjust the trim pot in a counter-clockwise direction until

the monitor indicates a FAIL condition. If properly

calibrated, the monitor should now indicate a FAIL

condition when the tester’s LEFT WS button is pressed.

To test the resistance of the right remote module, press

the black button labeled RIGHT WS on the tester. If

the remote module is properly calibrated, the monitor’s

audible alarm will sound and the RIGHT WRIST STRAP

LED will illuminate red. If the LED remains green, locate

the trim pot underneath the respective remote module.

Hold down the tester’s RIGHT WS button and carefully

adjust the trim pot in a counterclockwise direction until

the monitor indicates a FAIL condition. If properly cali-

brated, the monitor should now indicate a FAIL condition

when the tester’s RIGHT WS button is pressed.

Testing the Ground Monitor

Refer to Figure 2 to see the connection setup for the

94373 to the SPI-20686 and Figure 3 for the 94391.

Make sure that the switch located on the face of the

tester is toggled to LEFT WS / RIGHT WS. If connected

properly, all three LEDs on the SPI-20686 and 94391

should be illuminated green.

Disconnect the cords from the banana jacks on both

remote modules. Next, toggle the switch located on the

face of the tester to OPEN GND / HI RESIST. Press the

red button labeled OPEN GND on the tester, and if the

monitor is functioning properly, its audible alarm should

sound and the GROUND MONITOR LED should

illuminate red.

Press the red button labeled HI RESIST on the tester,

and the monitor’s audible alarm should sound and the

GROUND MONITOR LED should illuminate amber.

If any of these conditions are not met, contact the

manufacturer for repair.

Installation Adjustments

Should your system alarm without obvious cause, first

troubleshoot and verify all connections. If all the

connectionsare correct, the base unit should be adjusted

to compensate for a different HBM (human body model).

We preset the units at the factory at 100pF and your

operator might be out of the tolerance range caused

either by body chemistry, bulk capacitance or impedance

differences.

Follow these steps to adjust and personalize the base

unit:

Locate the small hole underneath the desired remote

module. Inside this hole is a trim pot device that is

adjustable by using a small flat-head screwdriver.

With the system set up and operating, and the operator’s

wrist strap connected to the remote module:

Turn the trim pot clockwise until the LED illuminates

green. Disconnect the wrist cord from the band. An

audible alarm will sound and the LED will illuminate red.

If not, carefully turn the trim pot counter-clockwise until

the LED illuminates red. Reconnect the cord to the wrist

band. The alarm should cease and the LED should

illuminate green.

Ground Monitor

The SPI-20686 and 94391 include a ground monitoring

system that assures a positive ground connection for the

workstation. The resistance range is preset at the factory

to monitor that the connection to ground is within the

resistance range of 0.01 to 10 megohms. A visual and/or

audio alarm will verify pass or fault conditions.

CONDITION INDICATOR

PASS - Properly Grounded - LED Green

with Resistance less - No Audible Alarm

than 10 Meg.

HI RESIST - Grounded, but - LED Oscillate Green to

Resistance exceeds 10 Meg. Amber or Flashing Red

- Audible Alarm

FAIL - Loss of 1 or both - LED Flashing Red

redundant grounds, failure - Audible Alarm

of monitor, worktop, mat, etc.

Safety Issues

With regards to the safety issue, it is hard to conceive of

a safer situation than exists with the Ground Gard 5.5 as

designed.

1. The SPI-20686 and 94391 have a built-in safety

resistance of no less than 500k ohms at each remote

unit.

2. The transformer is wound on a split bobbin with 1500

volt insulation to assure no possible line leakage.

3. The circuits are double insulated by virtue of the

insulated plastic boxes.

4. 500k ohms internal to the SPI-20686 and 94391 and

one megohm in the wrist strap isolate the operator.

This may be varified by using a miltimeter set on ohms.

Connect the telephone type wire to the monitor and to

the remote unit. Place one end of the probe into the

banana receptacle at the remote, and the other to the

collar (power supply jack) located at the monitor.

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

Employee Owned

Limited Warranty, Warranty Exclusions, Limit of

Liability and RMA Request Instructions

See ESDSystem.com’s Terms and Conditions -

http://esdsystems.descoindustries.com/TermsAndConditions.aspx

Desco 的 SPI-20686 规格书

信息

帮助

联系我们

关注我们