Disconnecting means for medium voltage motors

[Red Wiggler]

We are working on an estimate for a water treatment plant, and the bid documents show some meduim voltage motors (4160 volts) for pumps that are being fed from gear located in another room (not with in sight). My problem is that the Bid Documents do not show any disconnecting means in the pump room for these motors.

I have looked at NEC 430-102 B (1) exception for guidance and it appears that you wouldn't need a disconnecting means to be located in the same room if situation meets the requirements of the exception.

If this is the case, then the MCC that is serving the motors (which is located in the other room) would need to be permantely capable of being locked-out in the "open" position. Would this satisfy the requirement.

The main thing is that if I included disconnecting means for the motors in the pump room, (which would be required to have a 316 steel enclosure) in my estimate, I will probably be un-successful in the bidding process. Since we are working off of bid documents, and not construction documents I feel that I should "estimate" only what is show on the drawings.

Is this a bad practice?

 

[iwire]

I have looked at NEC 430-102 B (1) exception for guidance and it appears that you wouldn't need a disconnecting means to be located in the same room if situation meets the requirements of the exception.

In my opinion the NEC use of the word "impracticable" is equal to imposable, not inconvenient, difficult or costly. It is not interchangeable with "impractical"

An example of impracticable would be trying to require a disconnecting means within sight of a submersible pump at the bottom of a well.

It does not sound like it would be impracticable to place the disconnects within site of these motors.

 

[weressl]

We are working on an estimate for a water treatment plant, and the bid documents show some meduim voltage motors (4160 volts) for pumps that are being fed from gear located in another room (not with in sight). My problem is that the Bid Documents do not show any disconnecting means in the pump room for these motors.

I have looked at NEC 430-102 B (1) exception for guidance and it appears that you wouldn't need a disconnecting means to be located in the same room if situation meets the requirements of the exception.

If this is the case, then the MCC that is serving the motors (which is located in the other room) would need to be permantely capable of being locked-out in the "open" position. Would this satisfy the requirement.

The main thing is that if I included disconnecting means for the motors in the pump room, (which would be required to have a 316 steel enclosure) in my estimate, I will probably be un-successful in the bidding process. Since we are working off of bid documents, and not construction documents I feel that I should "estimate" only what is show on the drawings.

Is this a bad practice?

All individual starters in MV Motor starters are equipped with a lockable disconnect. It would be perfectly aceptable to have that as the single mean of disconnect and lock-out provision in your case.

The additional gear would greatly reduce the reliability of the system. SS enclosures are great lookin' but you would probably pay more for it that the starter and they do not stop the tratment chemicals to rot out the electrical parts inside. Useless IMO.

The exception is in the mode of service and utilization of starters.

 

[iwire]

All individual starters in MV Motor starters are equipped with a lockable disconnect. It would be perfectly acceptable to have that as the single mean of disconnect and lock-out provision in your case..

Not to the NEC unless those controllers are in sight of the motors.

 

[mkgrady]

Any time you think including something in a bid that may make you non-competitive you should first seek a written pre-bid clarification. The answer will distributed to all bidders (make sure that is the case). This puts all bidders on a level playing field.

 

[weressl]

Not to the NEC unless those controllers are in sight of the motors.

Exception to (1) and (2): The disconnecting means for the
motor shall not be required under either condition (a) or
condition (b), provided the controller disconnecting means
required in accordance with 430.102(A) is individually capable
of being locked in the open position. The provision
for locking or adding a lock to the controller disconnecting
means shall be installed on or at the switch or circuit
breaker used as the disconnecting means and shall remain
in place with or without the lock installed.
(a) Where such a location of the disconnecting means
for the motor is impracticable or introduces additional or
increased hazards to persons or property
(b) In industrial installations, with written safety procedures,
where conditions of maintenance and supervision
ensure that only qualified persons service the equipment​

FPN No. 1: Some examples of increased or additional hazards
include, but are not limited to, motors rated in excess
of 100 hp, multimotor equipment, submersible motors, motors
associated with adjustable speed drives, and motors
located in hazardous (classified) locations.
FPN No. 2: For information on lockout/tagout procedures,
see NFPA 70E-2004,​

​

​

​

Standard for Electrical Safety in the​

Workplace

It seems to me that according to the OP, BOTH of those conditions exist.

 

[iwire]

Exception to (1) and (2): The disconnecting means for the
motor shall not be required under either condition (a) or
condition (b), provided the controller disconnecting means
required in accordance with 430.102(A) is individually capable
of being locked in the open position. The provision
for locking or adding a lock to the controller disconnecting
means shall be installed on or at the switch or circuit
breaker used as the disconnecting means and shall remain
in place with or without the lock installed.
(a) Where such a location of the disconnecting means
for the motor is impracticable or introduces additional or
increased hazards to persons or property
(b) In industrial installations, with written safety procedures,
where conditions of maintenance and supervision
ensure that only qualified persons service the equipment​

FPN No. 1: Some examples of increased or additional hazards
include, but are not limited to, motors rated in excess
of 100 hp, multimotor equipment, submersible motors, motors
associated with adjustable speed drives, and motors
located in hazardous (classified) locations.
FPN No. 2: For information on lockout/tagout procedures,
see NFPA 70E-2004,​

​

​

​

Standard for Electrical Safety in the​

Workplace

It seems to me that according to the OP, BOTH of those conditions exist.

We already went over the impracticable part of this, from the limited info we can not tell if it is truly imposable (impracticable) to locate the disconnects near the motors.

As far as increased hazard, I doubt that as well.

He may well fit into (B) but we just do not know, that is an AHJ call.

The NFPA wants to protect workers from injury buy requiring that motors almost always have a disconnecting means in sight. Pretty straight forward concept.:smile:

 

[weressl]

We already went over the impracticable part of this, from the limited info we can not tell if it is truly imposable (impracticable) to locate the disconnects near the motors.

As far as increased hazard, I doubt that as well.

He may well fit into (B) but we just do not know, that is an AHJ call.

The NFPA wants to protect workers from injury buy requiring that motors almost always have a disconnecting means in sight. Pretty straight forward concept.:smile:

Let me requote:

"FPN No. 1: Some examples of increased or additional hazards
include, but are not limited to, motors rated in excess
of 100 hp,"

So you are implying that this MV(4160V)motor is less than 100HP?

Or that the water treatment plant is NOT an "industrial environment", which in accordance with OSHA requiress LOTO procedures?

Or just trying to be funny?:roll:

 

[iwire]

Let me requote:

"FPN No. 1: Some examples of increased or additional hazards
include, but are not limited to, motors rated in excess
of 100 hp,"

So you are implying that this MV(4160V)motor is less than 100HP?

Or that the water treatment plant is NOT an "industrial environment", which in accordance with OSHA requiress LOTO procedures?

Or just trying to be funny?:roll:

No I am saying that just because a motor may be well above 100 HP does not automatically mean having a disconnecting in sight of it increases the hazard.

Of course you know FPNs are informational only, not code.

As far as the industrial question, there is more to it then if it's industrial or not.

 

[weressl]

No I am saying that just because a motor may be well above 100 HP does not automatically mean having a disconnecting in sight of it increases the hazard.

Of course you know FPNs are informational only, not code.

As far as the industrial question, there is more to it then if it's industrial or not.

Yep, you ARE hilarious.......

 

[iwire]

Yep, you ARE hilarious.......

No need to be an ass.

The NEC section in question is posted so members can make their own decisions.

 

[augie47]

I'm not sure how hilarious this all might be when it came to an accident lawsuit.
Mr. Weress, serious question (since you appear to have familiarity). How does the motor being in excess of 100 HP increase the hazard ?

Secondly, and just my thought; as an inspector I'd hate to hang my hat on "an industrial facility" alone. I'd certainly want to see some documentation of how they assured "only qualified personnel serviced the equipment". I've seem some awfully unsafe acts at a local sewage treatment facility.

 

[jim dungar]

Does this topic need a cooling off period?

Lazlo has validly pointed out that the NEC has published exceptions to the requirement that a disconnect be provided in sight of a motor. He has stated arguments that he would present to an AHJ, and he has acknowledged it is up to the AHJ to make the decision.

If you do not agree with the validity of allowing these published exceptions take it up in the 2014 code process.

Those that want to discuss their criteria for accepting these published exceptions, should keep the content "civil".

 

[iwire]

Does this topic need a cooling off period?

Lazlo has validly pointed out that the NEC has published exceptions to the requirement that a disconnect be provided in sight of a motor. He has stated arguments that he would present to an AHJ, and he has acknowledged it is up to the AHJ to make the decision.

If you do not agree with the validity of allowing these published exceptions take it up in the 2014 code process.

Those that want to discuss their criteria for accepting these published exceptions, should keep the content "civil".

Jim, I have no problem accepting validity of the exceptions.

What I do have a problem with is the assertion that an AHJ has to automatically accept that just because a location is industrial that the exception can be used.

Like Gus I have seen industrial locations that do not have "written safety procedures," or "conditions of maintenance and supervision ensure that only qualified persons service the equipment"

I also have a problem with the assertion that just because a motor is over 100 HP the AHJ has to allow the use of the exception.

And finally I have a problem with the assertion that I am 'hilarious' because I do not see things in the same light as others.

That was uncalled for and I make no appoligiy for pointing it out.

 

[weressl]

I'm not sure how hilarious this all might be when it came to an accident lawsuit.
Mr. Weress, serious question (since you appear to have familiarity). How does the motor being in excess of 100 HP increase the hazard ?

Why don't you ask somebody from the CMP? Those were the ones who included that as FPN as an EXAMPLE.

Secondly, and just my thought; as an inspector I'd hate to hang my hat on "an industrial facility" alone. I'd certainly want to see some documentation of how they assured "only qualified personnel serviced the equipment". I've seem some awfully unsafe acts at a local sewage treatment facility.

As an inspector it is outside your realm how the facility is operated. It is an over-reach. As a municipa facility it is clearly under the OSHA rules AND required to operate and maintain it's electrical system according to Subpart S among others and subject to the LOTO rules. Those rules are LAWFUL on Federal level while NFPA is a local REGULATION if it is even that much. So a higher than local authority already imposes rules that are only supportive of local rules, if any.

 

[iwire]

As an inspector it is outside your realm how the facility is operated. It is an over-reach.

No, it is not an 'over-reach' it is direct part of the exception

In industrial installations, with written safety procedures,
where conditions of maintenance and supervision ensure that only qualified persons service the equipment

An inspector must consider all three points to allow the exception, it is not 'meet one' and your good to go.

1. industrial installations
   
2. written safety procedures
   
3. supervision ensure that only qualified persons service the equipment

Now if the owners of the facility can demonstrate that all three conditions will be fulfilled at that point the AHJ would have to allow the exception.

 

[weressl]

Jim, I have no problem accepting validity of the exceptions.

What I do have a problem with is the assertion that an AHJ has to automatically accept that just because a location is industrial that the exception can be used.

Like Gus I have seen industrial locations that do not have "written safety procedures," or "conditions of maintenance and supervision ensure that only qualified persons service the equipment"

I also have a problem with the assertion that just because a motor is over 100 HP the AHJ has to allow the use of the exception.

And finally I have a problem with the assertion that I am 'hilarious' because I do not see things in the same light as others.

That was uncalled for and I make no appoligiy for pointing it out.

Except the OP was not asking for what the AHJ 'may' rule, but what the NEC allows the installation to be.

In my other reply to Mivey, I also explained why the AHJ may not be the authority in this case HOW a facility is operated. (Even though it is in the NEC.) Just like a local police is not authorized to enforce Federal Laws, it is not the AHJ's role to do that either. (Y'all need to take some civic courses.)

BTW hilarious and ass are two different categories of insults. I really found it humorous that you were attacking me - when I only quoted the NEC - while at other times you're the one who bash me over the head with the BOOK when I try to provide technical evaluation and not necessarily disputing Code compliance. Fragile ego and all that.......

But hey, maybe Obama will invite us for a beer.....

 

[iwire]

Except the OP was not asking for what the AHJ 'may' rule, but what the NEC allows the installation to be.

And I offered more info then they asked for, a common occurrence here at the forum.

In my other reply to Mivey, I also explained why the AHJ may not be the authority in this case HOW a facility is operated. (Even though it is in the NEC.) Just like a local police is not authorized to enforce Federal Laws, it is not the AHJ's role to do that either. (Y'all need to take some civic courses.)

The NEC can not 'control how the facility is operated' never said it could but it can and does consider how the facility will be operated when writing the sections and the exceptions.

BTW hilarious and ass are two different categories of insults.

I guess I missed the handout describing the categories of insults. :roll:

I really found it humorous that you were attacking me -

Please point out my 'attack' previous to your hilarious comment. Because all I did was present an opposing view.

 

[weressl]

And I offered more info then they asked for, a common occurrence here at the forum.





The NEC can not 'control how the facility is operated' never said it could but it can and does consider how the facility will be operated when writing the sections and the exceptions.



I guess I missed the handout describing the categories of insults. :roll:



Please point out my 'attack' previous to your hilarious comment. Because all I did was present an opposing view.

Now I understand why you called me an ass.

 

[augie47]

Why don't you ask somebody from the CMP? Those were the ones who included that as FPN as an EXAMPLE..

given the opportunity, I will. I was in hopes that your knowledge and experience might shed some light on the FPN.

As an inspector it is outside your realm how the facility is operated. It is an over-reach. As a municipal facility it is clearly under the OSHA rules AND required to operate and maintain it's electrical system according to Subpart S among others and subject to the LOTO rules. Those rules are LAWFUL on Federal level while NFPA is a local REGULATION if it is even that much. So a higher than local authority already imposes rules that are only supportive of local rules, if any.

I agree that facility operation is well outside my realm, but compliance with the NEC is not. Exception (b) sets forth some stipulations beyond the location being "industrial". If one wishes to take advantage of a Code "exception", I feel it is their obligation to show they meet the criteria set forth in the exception. Other than being a "treatment plant" I did not notice if the OP mentioned "municipal" or not and I have no idea what Subpart regulations they might be required to operate under. That is where I was leading with my comment. IMHO, some documentation would be in order before an inspector should sign off on any exception.