Pump disconnect

[Open Neutral]

So what little of the Code I know something about includes "in sight disconnects" meaning motors must have such right there. I think that is 430.102.

But it occurs to me that I have seen many residential well pumps, 30-600 ft down, and none had such. Why is that? Is there some exception that applies? I ask because that VFD I recently discussed is for one; the VFD will be inside and not in sight.

Will a lockable breaker feeding the VFD be sufficient?

 

[Dennis Alwon]

This is a widely overlooked code item. You can comply by installing a locking switch at the controller. I usually just use a dp switch with a lockable weatherproof cover install at the pressure switch. I think I am the only one in this area that does it.

 

[Open Neutral]

The controller logic/VFD/etc is all in a mech room in the basement. The well is outside, with not much visible.

So if I can padlock the breaker, that's a plus.

 

[ptonsparky]

I think it would be required if you could fit your skinny rear down there to work on it. Something about practicable is the exception. We use an a/c type disconnect next to the controller which most often for residential wells is the pressure switch.

 

[Open Neutral]

Even if I could fit, I could not shinny down 670 feet, much less back up again.

This "controller" is a 10,000 gal tank's level switch, with a flow switch, timer and other logic. But that is all LV.

 

[hurk27]

While this was brought up at several of the IAEI Western Sectional meetings, and it was discussed at length of it being a general accepted practice of using a double pole switch at the controller (pressure switch) location, it was pointed out that the 430.102(B)(1) exception(a) would be met as long as a lockable switch or cover was used.

The CMP panel at these meetings basically stated that a submersible type well pump met the wording of the exception as to the location of being impracticable to locate a disconnect within site of the motor.

 

[gndrod]

well...

well...

This is a widely overlooked code item. You can comply by installing a locking switch at the controller. I usually just use a dp switch with a lockable weatherproof cover install at the pressure switch. I think I am the only one in this area that does it.

Voila! I agree Dennis. The only code that comes close to a deep 3-wire submersible controller would be [409] industrial control panels. I have set pumps as far back as the early 1970's and have never had an inspector question what code was relevant.

 

[gndrod]

Well safety...

Well safety...

While this was brought up at several of the IAEI Western Sectional meetings, and it was discussed at length of it being a general accepted practice of using a double pole switch at the controller (pressure switch) location, it was pointed out that the 430.102(B)(1) exception(a) would be met as long as a lockable switch or cover was used.

The CMP panel at these meetings basically stated that a submersible type well pump met the wording of the exception as to the location of being impracticable to locate a disconnect within site of the motor.

Did any of the CMP ever set a well system? They should consider including a disconnect at the wellhead because the pressure switch is located at the pressure tank or storage tank locations. A remote well head may also just be a 3-wire controller that has a panel cover. When the cover is opened , the whole energized wiring is exposed. Yes the NEC keeps its distance from Safety in many ways.

 

[hurk27]

Did any of the CMP ever set a well system? They should consider including a disconnect at the wellhead because the pressure switch is located at the pressure tank or storage tank locations. A remote well head may also just be a 3-wire controller that has a panel cover. When the cover is opened , the whole energized wiring is exposed. Yes the NEC keeps its distance from Safety in many ways.

have you read 430.102? yes if the controller is at the well head then yes the disconnect is required to be located there, but what was brought up was the fact that most dwelling type submersible well pumps are at the most just a 4" - 6" white plastic pipe barely sticking out of the ground, and placing the disconnect at this pipe would still not meet the requirement of having the disconnect "within sight of the motor" required in 230.102 most pressure switch's are located remote in the dwelling at the pressure tank, and as long as the disconnect is capable of being locked in the open position it meets the exception I stated above.

Constant velocity (VFD) type submersible well pumps I have seen have the controller also located at the pressure tank around here?

 

[hurk27]

Just to point out that some submersible pumps including constant velocity type have the starting and run caps in a control panel that many times is located remotely most of the time at the pressure tank, without disconnecting all these conductors you would still have voltage on the motor, this is also in the exception of 430.102

also its not wise to disconnect a motor from a VFD while the VFD is energized, another reason to allow the disconnect before the VFD.

 

[Open Neutral]

In this case, there will be nothing at the wellhead save a box holding a splice from the well cable to the line to the mech room. ~60 feet the other way will be the tank barn with the float and flow switches.

My initial concern was someone pulling the disconnect while the pump was running; and thus toasting the VFD.

 

[hurk27]

On a VFD driven pump or what is called a constant velocity well pump, the pressure switch is not a switch, it is called a pressure sending unit, like a guage sending unit on a car, but it is nothing more then a 3-wire variable resistor pot that varies with pressure.

 

[hurk27]

In this case, there will be nothing at the wellhead save a box holding a splice from the well cable to the line to the mech room. ~60 feet the other way will be the tank barn with the float and flow switches.

My initial concern was someone pulling the disconnect while the pump was running; and thus toasting the VFD.

That is why I made that next post, the disconnect goes ahead of the VFD

 

[hurk27]

In this case, there will be nothing at the wellhead save a box holding a splice from the well cable to the line to the mech room. ~60 feet the other way will be the tank barn with the float and flow switches.

My initial concern was someone pulling the disconnect while the pump was running; and thus toasting the VFD.

Thats what is the normal around here, with start and run caps at the controller you will also have many conductors running out to the well head also.

It was also brought up about using a simple moldex type plug and receptacle at the well head for a remote disconnect but most agreed that the moisture content of the air in the well head cap would cause to high of a failure rate of this contact point, similar to the problem of installing a plug and receptacle in the top of a lift station for the ejector pump maybe not as corrosive but not a good design either way..

 

[ptonsparky]

Even if I could fit, I could not shinny down 670 feet, much less back up again.

This "controller" is a 10,000 gal tank's level switch, with a flow switch, timer and other logic. But that is all LV.

In your case the controller is the VFD, not the pressure switch, timer or any other logic device.

Constant Pressure systems vary. Franklins use a simple on/off pressure switch and not a transducer. I haven't taken the time to watch but my local pump installer says you can watch the pressure change ever so slightly as it cycles.

 

[gndrod]

wells...

wells...

Just to point out that some submersible pumps including constant velocity type have the starting and run caps in a control panel that many times is located remotely most of the time at the pressure tank, without disconnecting all these conductors you would still have voltage on the motor, this is also in the exception of 430.102

also its not wise to disconnect a motor from a VFD while the VFD is energized, another reason to allow the disconnect before the VFD.

Hi Wayne,
Normally I would agree with what you are pointing out, but 430.102 I believe is generally applicable to commercial-industrial installations using 3 ph, 600V+ and VFD's. ( Of the many domestic well systems I have set, only one was a 3ph configuration that would apply here.) All that I am familiar with were rural installations that utilized a 2-wire feed of a long distance from a well head to a barn or residence. Usually a captive pressure tank is located at the structure inside or at an attached shed. (re: water line friction and static level drop is less distance to outlets in the structure)

The two wire feed requires that the pressure switch be within 48" of the pressure tank to eliminate re-occurring surge cycling. In most cases a long distance 2-wire direct burial is fed to a remote wellhead that has a motor controller mounted to it for a 3-wire non-cap deep submersible that is of a higher hp rating. (re: usually 2.0 hp or larger)

Most residential using deep submersibles are 2-wire 240V, 1 ph feeds, and generally a 0.5 to 1.5 hp pump well supply unless agricultural use is of size significance from a single unit. (depending on the supply GPM and draw-down) I would sell the client on a small well house or in-ground sealed container (w/lock) for remote locations that kept livestock and farmers from running over an exposed head. In most cases, the lock gets lost and the enclosure becomes accessible. (i.e. In hunting season, poachers break-in for water refill access.)

Please understand, there are situations where safety can be improved for modern well systems exposure. If any proposal is to be made, I would include deep submersible well systems as an addition to Article 680 and 682 installation sections. (682.14 update?) I agree with Dennis that domestic well systems have been overlooked for wiring methods in rural and agricultural safety.

 

[hurk27]

Hi Wayne,
Normally I would agree with what you are pointing out, but 430.102 I believe is generally applicable to commercial-industrial installations using 3 ph, 600V+ and VFD's.

I would like to know where your reading that from?

Nowhere does it say article 430 is only for industrial installations, nowhere in 430.102 does it say only for industrial installation, and nowhere in section IX does it say for 600 volts + thats section XI 430.221 and above, areas of 430 does address industrial installs, like 430.102(B) exception (b) but (a) is for all installations, and was specifically referenced by the CPM panel at the meeting I posted in post 6 well knowing we were addressing a dwelling installation. I believe there was some proposals also addressing this which I will try and look up the ROP's for the 2005 code change.

Let me ask you this, with a submersible pump even 10' down a well how would you comply with the wording of the requirement of a disconnect as it is worded?

430.102(B)(1)

A disconnecting means
for the motor shall be located in sight from the motor location​

and the driven machinery location.

I would think it would be imposable to locate a disconnect "in sight" of the motor

Hence the exception:

(a) Where such a location of the disconnecting means​

for the motor is impracticable

 

[hurk27]

Please understand, there are situations where safety can be improved for modern well systems exposure. If any proposal is to be made, I would include deep submersible well systems as an addition to Article 680 and 682 installation sections. (682.14 update?) I agree with Dennis that domestic well systems have been overlooked for wiring methods in rural and agricultural safety.

I don't see where 680 or 682 would apply to a well pump motor or controller? its a motor driven appliance, that has to meet the requirements of article 430 which is for motors and their respective controllers?

Please read 90.3 as a understanding to how the NEC is laid out for ease of use(yea right) but thats the way I have to teach it.

 

[hurk27]

Here is one ROP from 2005:

Report on Proposals ? May 2004 NFPA 70​

11-65 Log #1122 NEC-P11
(430-102(B) Exception)​

Final Action: Accept in Principle in Part
Submitter:​

​

​

​

​

Grant Guymon, Comforce Technical Services​

Recommendation:​

Delete the following words in first sentence of Exception:
" ...to be in sight from the motor and the driven machinery location...".​

Substantiation:​

The present language suggests that the disconnect would still be required, even if the installation satisfied either (a) or (b) of the
Exception. I do not feel that was the intent of the panel. Otherwise a literal reading of the rule could end up requiring two disconnects,
with both possibly out of sight of the motor.​

Panel Meeting Action: Accept in Principle in Part​

Revise Section 430.102(B). Delete the words: "to be in sight from the motor and the driven machinery location" from the exception. In
FPN No. 1, replace "variable frequency" with "adjustable speed" and relocate the second sentence to follow FPN No. 2, to read as follows:
B) Motor. A disconnecting means shall be located in sight from the motor location and the driven machinery location. The
disconnecting means required in accordance with 430.102(A) shall be permitted to serve as the disconnecting means for the motor if it is
located in sight from the motor location and the driven machinery location.
Exception: The disconnecting means shall not be required to be in sight from the motor and the driven machinery location under either
condition (a) or (b), provided the 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 disconnecting means shall be permanently installed on or at the
switch or circuit breaker used as the disconnecting means.
(a) Where such a location of the disconnecting means 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 variable frequency drives, and motors located in
hazardous (classified) locations.
FPN No. 2:For information on lockout/tagout procedures, see NFPA 70E-2000, Standard for Electrical Safety Requirements for
Employee Workplaces.
The disconnecting means required in accordance with 430.102(A) shall be permitted to serve as the disconnecting means for the motor
if it is located in sight from the motor location and the driven machinery location.​

Panel Statement:​

The action taken by the panel clarifies correct application of the exception.​

Number Eligible to Vote: 14​

Ballot Results: Affirmative: 14

As you can see VFD's are covered in the exception as an added hazard to property if motor is disconnected from a live VFD, as is submersible pump motors, see FPN 1

And heres one arguing a reason to not allow the exception for a submersible well pump:

Report on Proposals ? May 2004 NFPA 70​

11-64 Log #3272 NEC-P11
(430-102(B) and Exception)​

Final Action: Reject
Submitter:​

​

​

​

​

Joseph A. Hertel, Safety and Buildings / Rep. Dept. of Commerce, State of Wisconsin​

Recommendation:​

Delete current language of 430.102(B) and the Exception, replace with:
430.102(B) Motor. A separate disconnecting means shall be located in sight from the motor location and the driven machinery
location.
Exception: A disconnecting means, in addition to the controller disconnecting means required in accordance with 430.102(A), shall
not be required for the motor where the disconnecting means for the controller is individually capable of being locked in the open
position. The provision for locking or adding a lock to the disconnecting means shall be permanently installed on or at the switch or
circuit breaker used as the disconnecting means.​

Substantiation:​

The change in the 2002 NEC to this section did not address current practice of a locking disconnect at the controller location. The FPN
implies that it may be impracticable or hazards increased when disconnects are added for submersible motors, and motors located in
hazardous locations among others. The addition of disconnects in hazardous locations can be accomplished with the appropriately
listed equipment. While this is expensive, it does not increase the hazard merely the cost of the installation since the equipment is
clearly evaluated for the use. A well pump is an example of a submersible motor and while it is impracticable to place a disconnect in the
casing so as to be insight less than 50 feet from the motor, it can be placed at the top of the casing. The use of locking disconnects at the
controller for motors has been in the NEC since the 1987 edition. Instead of adding additional requirements to the NEC, it may be more
appropriate to educate users as to why there are locking mechanisms on these already present disconnects.​

Panel Meeting Action: Reject
Panel Statement:​

The submitter has not provided any technical substantiation to warrant this revision. The proposed new exception is the exception as it
appeared in the 1999 NEC. The Panel reaffirms its position that where practicable and where the installation does not add increased or
additional hazards, the motor disconnecting means shall be located within sight from the motor and driven machinery. The Panel further
reaffirms its position on the effectiveness of lockout/tagout programs that were established during the 2002 Code cycle. The data
reviewed by the panel on the effectiveness of Lockout/Tagout programs shows a correlation between the type of the facility and the
effective implementation of the program. Part (b) of the exception currently provides that for industrial installations, with written safety
procedures, where conditions of maintenance and supervision ensure that only qualified persons service the equipment, the local
disconnecting means is not required. This provision should ensure that only those facilities that are most likely to have an effective
Lockout/Tagout program can utilize the exception.​

Number Eligible to Vote: 14​

Ballot Results: Affirmative: 14

 

[gndrod]

Regional Applications

Regional Applications

Just to point out that some submersible pumps including constant velocity type have the starting and run caps in a control panel that many times is located remotely most of the time at the pressure tank, without disconnecting all these conductors you would still have voltage on the motor, this is also in the exception of 430.102

also its not wise to disconnect a motor from a VFD while the VFD is energized, another reason to allow the disconnect before the VFD.

Wayne,
My apologies for quoting The National Well Driller. You might be familiar with this well trade subscription about the well pump installation variations that exist far out in the middle of agri fields that are a part of the water system industry. I can see why I am confused about what you are pointing out. Which NEC exception are you quoting or referring to in 430.102 Location? I admit, I am not on the same page of where you and your committee seem to be when it comes to actual experience in a different field.

First of all, if you followed my long post explaining what my experience is in well pump system setups for rural residential, I think you would understand the dis-associating with VFD's and controllers. The NEC 430 VIII is about Motor Control Centers that covers control of motors, lighting and power circuits that I do not equate with in domestic water well systems out in the field. Maybe in mine pumping systems I can agree but not in simple rural residential and farm setups that I support the driller and referring to.

If 430.102(A) Controller Exception No.1 does not give a clue about circuits over 600 Volts, I don't know what does. Experience in installing 2-wire systems 240V, 1 ph that are out of sight as far as 200- 300 feet is very common on the West Coast...maybe that is the difference. The setting up a simple system is very apparent that residential does not utilize 600V source well systems, especially in the high country. I would like to sit in on some of your group discussions so I can see where the experience is different...so I can learn something new. Where are these deep submersible well systems you are referring? Please explain. Tx.