en_US English
en_US English es_MX Spanish
My Account
Brainfiller.com Logo Horizontal
Facebook Linkedin Youtube

Technical Articles

Arc Flash Forum Update

Arc Flash Label Updating – How Many Times?

November 14, 2016

NFPA 70E requires that an Arc Flash Risk Assessment be updated when a major modification or renovation takes place. It shall be reviewed periodically, at intervals not to exceed 5 years, to account for changes in the electrical distribution system that could affect the results of the arc flash risk assessment. Countries outside of the US that do not use NFPA 70E may have a similar label review/updating requirement. NFPA 70E further states that where the review of the arc

Read More »

Maximum Short Circuit Current

November 9, 2016

The intensity of an arc flash is dependent on the magnitude of short circuit current. Lower voltage systems (less than 600 volts) tend to have the highest short circuit currents. Here is this weeks question: What is the maximum short circuit current that you have seen? less than 50 kA greater than 50 kA greater than 100 kA greater than 150 kA ANSWER

Read More »

Using gloves with a stick

November 7, 2016

1910.269 requires arc flash protection for hands with exceptions when wearing leather protectors over rubber gloves, and when wearing heavy duty work gloves. The workers state that sticks should be used bare handed, and that work gloves will contaminate the stick. Any advice on this topic? Leather gloves aren’t going to contaminate a hot stick unless for instance they get saturated in creosote or other materials. Granted there are tons of nasty, sticky materials in the utility work site and

Read More »

DC Arc Flash Boundary

November 5, 2016

Could i use the (DB) empirically derived model equation of IEEE Std 1584-2002 to calculate the Flash-protection boundary (for box configurations) and the Lee (DB) equation (for open air configurations)? I can´t find a equation for DC Arc flash boundary. READ MORE.

Read More »

100A panel with 200A “gutter mounted” main. WTF??

November 2, 2016

Came across this today while surveying. The original drawing shows this panel with a 100A branch mounted main. Well, someone needed that breaker for another panel and removed it and installed this instead. Not in the photo: 4/0 feeder spliced inside an adjacent panel with #2. #2 goes through wireway to this 200A “gutter mounted” MCB which had been removed from the adjacent panel. Adjacent panel was re-fed from a different source. Sheesh! Oh, and the 4/0 feeder (and the

Read More »

Maintenance of LV components inside HV cabinet

October 26, 2016

Good Morning All, I am from the Safety Office and our organization prohibits working on electrical components/systems above 600V. I have a situation that I need advice on. Here is the background: There is a group of Electronics Technicians/Engineers who believes they are responsible of an electrical system just because it resides in their occupied building. Inside this building is an 15kV CB which disconnects a transformer bank 11.5kV:570V, 540V and an 8.32kV harmonic filter (in a cabinet) from the

Read More »

RELT or ARM Arc Flash Labels

October 25, 2016

It always seems as if we are kicking the dead horse on arc flash labels but I was just interested in your opinion of how to label a piece of equipment which is fed from a circuit breaker with an Arc Flash Reduction Switch (ARMS) or Reduced Energy Let-thru (RELT) switch. We are currently performing a project with several new circuit breakers using the RELT switch. Install two labels on the equipment? One with ARMS and one without? To avoid

Read More »

Maximum distance where arc flash label is still readable

October 24, 2016

This week’s question is very subjective and is based on all kinds of variables such as lighting, eye sight etc. For an average person under normal conditions: What is the MAXIMUM distance where the typical arc flash label details are still readable? Less than 4 ft. (1.2 M) Between 4 and 8 ft. (1.2 to 2.4 M) Between 8 and 12 ft. (2.4 to 3.7 M) Something greater than 12 ft. (3.7 M) It depends ANSWER QUESTION

Read More »

I wonder what the withstand rating is on these?

October 19, 2016

I’ve known about these switches in this old house for at least 15 years but never took any pics. I was over there today and thought I would share to see if they are common in other parts of the country. Out east maybe? I’ve only seen these switches in this one house here in Indiana. The house was built in 1931. I assume these are original to the building but don’t know for sure. Yes, they are manufactured by

Read More »

Recent Posts

Categories

Categories