Industrial establishment, multiple buildings, emergency power coming from another building but there is only an emergency push button to serve as local disconnect for the emergency power source. Is this legal?
Where does the incomming generator power conductors land? Where is that termination in relation to the utility feed? I don't think generator disconnects are required in the same fashion as a service. What is it that bothers you regarding the installation?
[This message has been edited by Ron (edited 03-18-2002).]
Re: Remote Em. Gen./ no local disc.#80207 03/18/0204:29 PM03/18/0204:29 PM
Sparky, don't know what 02 changes in 430 you are referring to. Don, you seem to have pinpointed the right part of the code. I guess my question has to do with two issues. Does a mushroom push button for remote control of a generator magnetic disconnect suffice for a "disconnect" when there is no visible means to immediately confirm that power was indeed shut off? And, secondarily, where can one find out exactly what is required to comply with exception #1 of 225.32? Seems to me that not being able to positively know if power has been fully shut down would not be "safe switching procedure".
[This message has been edited by Elzappr (edited 03-20-2002).]
Re: Remote Em. Gen./ no local disc.#80210 03/21/0209:45 PM03/21/0209:45 PM
Elzappr The exception to 430.102(B) was revised for the 2002 Code. I read it as requiring a disco by the controller and the motor. Not to hijack your thread, it's a similar concern.......
handbook commentary......... 430.103 Operation. The disconnecting means shall open all ungrounded supply conductors and shall be designed so that no pole can be operated independently. The disconnecting means shall be permitted in the same enclosure with the controller. FPN:See 430.113 for equipment receiving energy from more than one source. The Code requires that a switch, circuit breaker, or other device serve as a disconnecting means for both the controller and the motor, thereby providing safety during maintenance and inspection shutdown periods. The disconnecting means also disconnects the controller; therefore, it cannot be a part of the controller. However, separate disconnects and controllers may be mounted on the same panel or be contained in the same enclosure, such as combination fused-switch, magnetic-starter units. Depending on the size of the motor and other conditions, the type of disconnecting means required may be a motor circuit switch, a circuit breaker, a general-use switch, an isolating switch, an attachment plug and receptacle, or a branch-circuit short-circuit and ground-fault protective device, as specified in 430.109. If a motor is stalled or under heavy overload and the motor controller fails to properly open the circuit, the disconnecting means, which must be rated to interrupt locked-rotor current, can be used to open the circuit. For motors larger than 100 hp ac or 40 hp dc, the disconnecting means is, in accordance with 430.109(E), permitted to be a general-use or an isolating switch where plainly marked “Do not operate under load.”
wellll...an E-stop will do that right???
Re: Remote Em. Gen./ no local disc.#80211 03/21/0211:47 PM03/21/0211:47 PM
Yeah, I can see where they are similar. Additionally, in 430.104, the D has to plainly indicate whether it is in the open or closed position. I have been under the impression that that provision fits into the scheme of "safe switching procedures" that was mentioned within the context of the emergency generator feeder disconnect..but I have no way to verify that. So, I guess my query centers around the intended content for so-called "safe switching procedures".