Six key symbols for Electrical Safety
Electrical Safety is well standardized, in the sense that there are may technical documents written on the Subject, normally by the International Electrotechnical Commission, or IEC.
Electrical Safety and Arc Flash Mitigation
Contactors used in Safety Applications
There are three types of contactors used in Safety-related control Systems:
Electrical Safety and Arc Flash Mitigation
ISO 13849-1
It is one of the two standards used in machinery and, at least in Europe, it is the most used of the two, the other being IEC 62061. It is divided in two parts:
Functional Safety
Direct Opening Action
The electrical output of an interlocking device has two types of technologies
Machinery Safety
IEC 62061
This is the second standard applicable to machinery and, so far, the least used for the reasons explained in the book. However, there is confidence that, with the publication of the 2021 edition, there will be more and more machinery manufacturers wh...
Functional Safety
Fault Considerations and Fault exclusion.
A Safety system has to be reliable; but how many faults should be taken into consideration? A redundant system can be designed with two sensors and two redundant final elements but, in case of two faults, we are in trouble! In general, the following ...
Functional Safety
A brief history of Functional Safety standards
In machinery, one of the first safety standards was BS 5304 “Code of Practice for Safety of Machinery”, first published in 1975
Functional Safety
Functional Safety in USA and Canada: the Concept of “Control Reliable”
In Europe, in the 90’s, the reference standard for Functional Safety of Machinery was EN 954-1. At that time, Safety-related Control Systems were classified in 5 Categories: from Category B to Category 4.
UL and CSA Conformity
Short-circuit aspects: NEC vs IEC
There are several differences between the North American and International electrical standards (published by IEC).
One of those differences is the way...
UL and CSA Conformity
The three legs of North America product Safety
THE DOUBT: is the knowledge of the NEC, or NFPA 70, important when assessing the electrical conformity of my machinery for export to USA?
CONSIDERATION 1: When...
UL and CSA Conformity
Safety Contactors and their usage
THE DOUBT: What is a safety contactor and is their usage compulsory in a Safety related control circuit?
CONSIDERATION 1: There are 2 main types of contac...
Functional Safety
Well-tried components
THE DOUBT
Why are well-tried components important in Machinery Safety?
CONSIDERATIONS
The concept is defined in both ISO 13849-1 and IEC 62061. Those...
Functional Safety
