Page 12 - ABEBA OCCUPATIONAL AND SAFETY SHOES

ESD

Avoiding ESD means understanding ESD.

Highest quality and reliability are indispensable in this area. Accordingly, we use our expertise in the field of ESD to avoid the
dangerous effects of ESD, such as damage to electronic components in production.
Electrostatic discharge
We are continuously expanding our range of ESD safety footwear and are constantly addressing the following situations:
• What actually happens in the production of highly sensitive components? ESD (short for electrostatic discharge) refers to the equalisation of large potential dif-
ferences, which causes high voltage pulses. Under certain circumstances, this voltage
• Which static charges of the employees are still present despite extensive ESD measures?
pulse can damage or even destroy electronic components.
• Monitoring of employees in the workplace, measured in Volt.
Potential differences are often caused by friction or contact and separation of two ob-
jects. In the process, a human being can be charged to approx. 30,000 V. Only from a
strength of the electrostatic discharge of approx. 3,000 V is it perceptible to humans as
the feeling of an electric shock. Electrostatic sensitive components, on the other hand,
can sometimes only tolerate 5 - 30 V blocking voltages. Therefore, when working with
Information electrostatically sensitive components, measures must be taken to reliably reduce charg-
es and therefore also avoid rapid discharges.
Electrical contact resistance and protection against electrostatic phe-
nomena. Measures against static discharges are described in EN 61340-5-1. Effective personal
ESD shoe as primary measure in the person / shoe / floor system. earthing through the use of suitable ESD footwear serves to protect sensitive compo-
nents by continuously dissipating charges.
Ω
Insulating shoes In practice, the conductivity of ESD shoes is not only significantly influenced by the
EN 50321 prevailing climate (humidity and temperature), but also by factors such as soiling, floor
conditions, human body resistance. ESD officers in companies are therefore required to
10 9 regularly check whether the ESD products used still have the required effect. In areas
Anti-static shoes where ESD shoes are worn, the floor resistance should be such that the protective func-
EN ISO 20345, EN ISO 20347 tion provided by the shoe is not nullified. The performance of “walking tests” allows the
A human-shoe-floor system to be tested.
EN ISO 20344:2011
1 x 10 ≤ R ≤ 1 x 10 Ω (0.1 to 1000 MΩ) Warning advice: ESD shoes are not suitable for electricians or when working on
9
5
10 8
Electrostatic dissipative shoes sources of electrical stress.
EN 61340-4-3
1 x 10 ≤ R ≤ 1 x 10 Ω (0.1 to 100 MΩ) Wearing EN 61340-4-3 and EN 61340-5-1 certified footwear is highly recommended, not
8
5
only in the area of the chemical and electrical industries, when handling flammable liq-
System: Person / uids and gases, paints and varnishes, but also in traditional areas with intensive dust
shoe / floor exposure such as printing plants, mills, grain warehouses, or woodworking industries, as
EN 61340-5-1 ESD footwear can reduce the risk of ignition due to an electrostatic discharge.
R ≤ 3.5 x 10 Ω (0.1 up to 35 MΩ)
7
g
Technical rules for safety at work (TRBS 2153)
According to TRBS 2153 point 7.1, dissipative footwear with a contact resistance of less
than 100 MOhm must be used in potentially explosive atmospheres. Our shoes meet
10 5 this requirement according to EN 61340-4-3 (test with metal balls in the shoe on a metal
Conductive footwear
EN ISO 20345, EN ISO 20347 plate) and EN 61340-5-1 (test with human in the shoe on a metal plate).
C
EN ISO 20344:2011
R≤ 1 x 10 Ω (0,1 MΩ)
5

A and C: Additional requirements of electrical properties in occupational and safety shoes. R: electri-
cal resistance. R : Earth leakage resistance.
g
The use of test stations has become established for the daily functional
testing of the shoes. Here, the resistance of the person and the shoe is
measured. When performing the test, care should be taken to test both
feet separately.
12 13