Is Disconnect Switch required on this Electrical Control Panel?

[factoryrat]

We have an Electrical Control Panel that houses a PLC Processor, a couple of I/O Racks for PLC, and a couple motor starters for Conveyor Motors (480v, 3phase, 3 to 5 HP each). This, 6 foot tall, panel has no power disconnect on it. It is fed from another Control Panel that is located about 25 to 30 feet away. This other feeder Control Panel does have a Disconnect Switch on it that when shut ?OFF? kills power to Remote Control Panel.

Does this the Remote Electrical Panel need its own disconnect, or does the Feeder Panel?s disconnect switch fulfill the minimum code requirements?

If you could supply code reference it would be greatly appreciated.

 

[augie47]

Normally each motor controller is required to have it's own disconnect, but there are exceptions for multi-motor equipment. It would be best to look at 430.102 and the exceptions to see how your situation fits

 

[factoryrat]

I just looked at the Conveyor Drive Motors and there are actually 3 motors. The largest is 2 HP and the other two are 1 HP each. Each Conveyor Motor has a Disconnect Switch mounted within a couple feet of the individual motor. These Conveyor Motors are fed from the remote electrical Control Panel with no disconnect on it.

I guess I am looking at this from a Safety perspective. Here at work in our factory we have a couple good people that believe we need a disconnect on the, above mentioned, Electrical Control Panel. They may be right? I am not sure. But before we spend the time and money of adding a disconnect to this panel I want to know what is required by NEC. We want to be safe and smart.

We have Safety Placarding on Remote Electrical Control Panel (one with nof disconnect) that says before you do any work in this electrical enclosure be sure to turn off power from the disconnect on the Main Electrical Control Panel. Does this meet NEC requirements?

Appreciate any thoughts or suggestions on this concern.

 

[augie47]

Someone else may, but I don't know what more to tell you than I did above.
This is covered by 430.102 which, because of the exceptions, is a bit lengthy to post here for you to read.
Keep in mind, that section addresses disconnects for the motors AND the controllers. Since you are asking about the controller, I will post the basic rule:
430.102 Location.
(A) Controller. An individual disconnecting means shall be provided for each controller and shall disconnect the controller. The disconnecting means shall be located in sight from the controller location.

As noted, there are exceptions which might apply to your particular situation, so I again urge you to read 430.102

 

[petersonra]

there is no general requirement that a disconnect switch be part of an industrial control panel. it can be separate from it. it is typically included as part of an ICP as it is a convenient place to locate it.

 

[factoryrat]

Thanks augie47,

I am an old electrician by trade but my job has me doing a lot of non electrician stuff. I looked at NEC section you sugested. I looked at the definition of Controller:

Article 100 definitions
Controller. A device or group of devices that serves to govern, in some predetermined manner, the electric power delivered to the apparatus to which it is connected. A controller may be a remote-controlled magnetic contactor, switch, circuit breaker, or other device that is normally used to start and stop motors and other apparatus and, in the case of motors, is required by 110.9 and 430.82 to be capable of interrupting the stalled-rotor current of the motor. Stop-and-start stations and similar control circuit components that do not open the power conductors to the motor are not considered controllers.

I think that definition fits my electrical cabinet. Inside I got: fuses, motor starters, relays, PLC processor and it's I/O - all for controlling conveyors. The only thing I am missing is a disconnect switch mounted directly on outside, of previsiosly mentioned, panel.

I also found this wording; "Industrial facilities that comply with OSHA, 29 CFR 1910.147, The Control of Hazardous Energy (Lockout/Tagout), are permitted to have the disconnecting means located remotely. (DOES THIS APPLY TO ME?)Section 430.102 clearly requires that individual disconnect switches or circuit breakers must be capable of being locked in the open position. Disconnect switches or circuit breakers that are located only behind the locked door of a panelboard or within locked rooms do not comply with the requirements of 430.102. The provision for locking or attaching a lock to the disconnecting means must be part of the disconnect and a permanent component of the switch or circuit breaker."

I think I am Legal and safe based on what I read in 430.102 - what do you think??

 

[factoryrat]

Bob what does ICP stand for?

 

[augie47]

If, as the exception states, the controllers are "coordinated controllers that drive several parts of a single machine or piece of apparatus" then a single disconnect, in sight from the controllers, can suffice. If not, each controller would need a individual disconnect.

Does the Control Panel meet Art 409 ? Is it U.L. or other NRTL listed ?

 

[pfalcon]

Remote disconnect is permissable with the appropriate signage. At that point you will want to bolt the panel rather than provide a handle. Requiring a tool helps reinforce the lockout requirement and meet safety standards.

Using a second disconnect can create problems in that only part of the machine is naturally shut off when the downstream panel is pulled. Most disconnect vendors sell a pair of small gadgets that can be added to the two disconnects in question. They trip the Primary disconnect when the Secondary is pulled. Signage is still important due to restart issues.

Remember that for OSHA purposes that using a common tool, such as a screwdriver or pliers, as a handle or hand extension is considered "operating by hand" not using a tool. Example, the small quarter-turn bolt in the handle of many control panel doors that requires a screwdriver to turn - is HAND OPERATED.

 

[petersonra]

Bob what does ICP stand for?

industrial control panel

 

[factoryrat]

Augie47 Article 409 is a good code reference. Thanks.

I do not know if the panel is UL or other NRTL listed.

The Panel which is the topic of our discussion was a used Industrial Panel that some of our Trades modified to be used to control the operation of a couple Conveyor Systems we added in our Plant. It is definitely an Industrial grade Panel. It is made of a heavy gauge metal. I do not know if it is UL approved. How does one go about getting an UL approval? You guys are killing me. This is good though ? I appreciate the information.

 

[jmcdonald@irwinindustries]

Can you pull through a power panel to feed another panel?

Can you pull through a power panel to feed another panel?

I have a situation were an engineer has drawn one conduit with two feeder circuits going to one power panel. The second circuit will pull through this panel and go into another conduit and feed the next panel. I believe that this is a code violation but cant seem to locate it. Please let me know if you know what section it is in. Or if this is legal or not.

 

[roger]

I have a situation were an engineer has drawn one conduit with two feeder circuits going to one power panel. The second circuit will pull through this panel and go into another conduit and feed the next panel. I believe that this is a code violation but cant seem to locate it. Please let me know if you know what section it is in. Or if this is legal or not.

It's fine. See article section 312.8, be sure to read the whole section.

Roger