| Author | Message | ||
     Ccryder |
Got a quick question. Does the NEC require in 480v panel (with a motor starter) that the disconnect have an external mechanical actuator? We have 20-30 year old equipment that someone changed out the disconnect with a different type that doesn't interface with the exterior door interlock. I have a Maint Mgr that claims there is no reason to have the door lock/ interconnect operate the disconnect inside. Being a dumb old ME gut feel tells me he's FOS but I don't know better. I do know that LOTO and ARC flash safety would be nonexistant w/o the external interlock. Please oh great Collective, tell me which path to follow..... TIA Neil S. | ||
| Kenm123t |
If it had it before he has modified the panel and voided its UL rating. Your probably in OSHA violation for using improperly repaired safety equipment | ||
| Eaton_corners |
Check NFPA 70E for arc flash protection standard. I think it needs to be changed. | ||
| Ccryder |
Thanks guys. That's what I thought that if it came from the Mfg. it had to be equal or better. W/O being able to de-energize the disconnect before opening the panel, the Technician has zero protection if it arcs. I have too many stories about this "mgr". I'll just put my foot down and tell him to get it back to original or better to be in compliance. Time4Sleep Neil S. | ||
| Dalton_gang |
So you are saying that the switch can be opened and closed with the door open? This doesn't sound right for 600v equipment. Keep in mind that with this voltage you should be using 600v rated equipment. Some equipment allows you to disable the door interlock with a screw driver so the door can be opened while the switch is closed but I don't think it will allow you to open and close the switch until the door is closed. Now if the installed equipment is 250v rated then this may be working properly but is the WRONG equipment for this application. Kenm123t is right. If the equipment has been altered in any way the UL listing is void and the equipment should PROBABLY be taken out of service. Be careful | ||
| Rwven |
Contact the authority having jurisdiction. They can answer your question to everyone's satisfaction. IMO as a licensed master electrician the externally mounted disconnect switch meets all the requirements of the NFPA as a motor controller disconnecting means. There is a lot of "grey" area in installations that are supervised by qualified personnel. Only qualified personnel should be in the motor control cabinet in the first place. | ||
| Ccryder |
The Mgr that was questioning my observations caved in when I showed him the following. He is getting quotes on getting these disconnects repaired/ replaced. Thanks all. NFPA79 standard Electrical disconnect switches must fully comply with the following requirements of the NFPA79 standard*: • Isolate the electrical equipment from the supply circuit and have one “OFF” (open) and one “ON” (closed) position only • Have an external operating means • Be provided with a permanent means permitting it to be locked in the “OFF” (open) position only independent of door position • Be operable, by qualified persons, independent of the door position without the use of accessory tools or devices NFPA 70E Article 120.2(E)(1). If the equipment has been altered after the manufacturing date it would need to follow the updated standard. NFPA 70E Article 110.8 (B)(4) Safety interlocks: Only a qualified person shall be permitted to by-pass or defeat an electrical safety interlock and then only temporarily while working on the equipment. When work is completed the electrical safety interlock must be returned to it’s original condition. | ||
| Ferris_von_bueller |
I would run it by someone in the Obama administration before doing anything | ||
| Ccryder |
FVB I think you are on to something...... Next we will ask them to help with health care, what an idea!!!!!!!! Anyway, I'm learning more about all sorts of stuff with the NFPA and NEC, great fun to put me asleep. Thx for the help. Gotta run. Neil S. |
