v57
Mechanical
- Jul 6, 2006
- 2
We design and build packaging machinery and have an odd request from a customer. They wish to run a compressed air line and 120VAC power through our machine to power a secondary piece of equipment at the discharge of our machine. The twist is they want power and air to remain ON even if our machine is put into emergency stop mode. The power source for this would come from our main electrical cabinet upstream of our e-stop circuit and the air supply would come from upstream of our main air dump valve that opens during e-stop. They would not connect to any devices on our machinery, only to the downstream piece of equipment which resides outside our interlocked guard package.
Our question is, does this violate an emergency stop requirement such as NFPA 79 "Electrical Standards for Industrial Machinery" which contains statements such as :
9.2.5.4.2.2 Emergency switching off shall be accomplished by
disconnecting the incoming supply circuit of the machine effecting
a Category 0 stop. Where the machine cannot tolerate
the Category 0 stop, it shall be necessary to provide other protection
(e.g., against direct contact), so that emergency switching
off is not necessary.
Any help on this would be greatly appreciated.
Our question is, does this violate an emergency stop requirement such as NFPA 79 "Electrical Standards for Industrial Machinery" which contains statements such as :
9.2.5.4.2.2 Emergency switching off shall be accomplished by
disconnecting the incoming supply circuit of the machine effecting
a Category 0 stop. Where the machine cannot tolerate
the Category 0 stop, it shall be necessary to provide other protection
(e.g., against direct contact), so that emergency switching
off is not necessary.
Any help on this would be greatly appreciated.