NFPA 79:2002 9.2.5.4.1.1(3) states "Reset of an emergency stop circuit shall not initiate a restart."
The question is what constitutes "initiating a restart".
It is ok for the PLC to control the re-energization of the power. But no power to the motors shold be restored...
To Alexit and Reddog:
The problem with the LCD panel (monitor) is that it has no UL ratings at all. None of them do apparently. Therefore UL considers the opening for the LCD panel to be a 14" square opening in the cabinet and requires a viewing window.
Hanginf the LCD panel on the...
UL508 sends me to UL508A which sends me to UL746C for the required test.
Loacting the LCD panel outside the electrical elclosure would require another enclosure (more bucks and assembly time).
So, I am about to do the 5 inch flame test to see if we have a snowball's chance. (Let's see: an...
Yes, he is a field engineer with UL.
UL 508A section 23 covers observtion windows. 23.3 says an observation window must be polycabonate, 1/8" thick minimum, and have a 5VA flammability rating.
We design our own cabinets and our entire machine is UL listed.
If we do not comply with the...
I do not know about the particular EN you are looking for, but there are a number of places I get European standards from. Try Global Engineering (global.ihs.com), www.nssn.org, and www.newapproach.org.
We are changing to LCD monitors in the machine tools we manufacture. UL is saying that the opening for the monitor must have a polycarbonate cover with a 5VA flammability rating.
1. Is he correct?
2. Any way to get around this?
3. Anyone have any experience with this.
Our plastics vendor...
