Disconnect means Location (HVAC) 440.14

Status
Not open for further replies.

Mart_OB

Member
Sometimes, we provide unit with vestibule and with control panel inside the vestibule.
The Nec article 440.14 says that the disconnect means shall be located in sight. But it says it can be installed ON or WITHIN the unit.
The question is : Are we obligated to have a disconnect remote from the control box when the control box is inside a vestibule?
Is there an impact if the client can open a door that gives direct access to the motors (without using the vestibule)?

Up to now we provide a disconnect on the unit and one Inside the control box, but I would like to reduce the unit cost by removing the disconnect on the unit.


Thanks for your help
 

Attachments

  • HVAC-Disconnect.jpg
    HVAC-Disconnect.jpg
    76.9 KB · Views: 7
IMO, You are obligated to have a disconnect means within sight from the motor.
Note that 440.3 references Art 430 as a guide except as modified by Art 4440 and 430.102 would require the disconnect in sight from the motor.
 
I would believe that the exception to 430.102(B)(2) would allow what the OP wants if it can be locked open:

(B) Motor. A disconnecting means shall be provided for a
motor in accordance with (B)(1) or (B)(2).
(1) Separate Motor Disconnect. A disconnecting means
for the motor shall be located in sight from the motor location
and the driven machinery location.
(2) Controller Disconnect. The controller disconnecting
means required in accordance with 430.102(A) shall be permitted
to serve as the disconnecting means for the motor if it
is in sight from the motor location and the driven machinery
location.

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.
 
Wayne, you left out the rest of that.

(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

Do you think (a) or (b) applies to the OPs situation?
 
If this equipment is actually Article 440 equipment, there really isn't a "remote lockable disconnect" provision in 440.14. The exception may work for some refrigeration equipment, but would not work for most air conditioning equipment as the controller for AC equipment is most often part of the AC equipment and not remotely located like it often is for motors or some refrigeration equipment.
 
Wayne, you left out the rest of that.



Do you think (a) or (b) applies to the OPs situation?

Yep it was on the next page in my 2011 PDF, I would believe that as large as this unit is, I would expect that it would only be worked on by qualified persons IMHO

If this equipment is actually Article 440 equipment, there really isn't a "remote lockable disconnect" provision in 440.14. The exception may work for some refrigeration equipment, but would not work for most air conditioning equipment as the controller for AC equipment is most often part of the AC equipment and not remotely located like it often is for motors or some refrigeration equipment.

As Bob pointed out with this being a single piece of equipment most likely UL listed without any disconnecting means at each motor within the unit, I can't see any reason requiring multiple disconnects located inside of these units at each motor, how many other types of equipment we see that the motor is located inside of the equipment but yet we are only required to have one disconnect for the equipment as a whole, especially if this HVAC unit is UL listed as is, even field installing a disconnect inside of a UL listed piece of equipment can void the UL listing as you now have added to it, also if the unit is UL listed as a whole should an inspector be looking at the insides of the unit?

Should a furnace installed in my home require the disconnect be located close to the motor or motors? many times they are located within sight of the unit as a whole but in some of these cases if your down standing on your head working on the motor you can no longer see the disconnect, yes this is an extreme but fits the wording of requiring a disconnect within sight of the motor.

I think the OP should address this to the listing agency to see what they think, even a moldex plug at each motor can solve this problem because it could be considered a disconnect, many appliance's use moldex plugs on the motors and maybe this is the reason, but it has been done for years so I don't think it has anything to do with the NEC requirements but more of making it easier to replace the motor.
 
Yep it was on the next page in my 2011 PDF, I would believe that as large as this unit is, I would expect that it would only be worked on by qualified persons IMHO

That is not the only part of the requirement.

I service units like this often, you find them on the roofs of large stores and office buildings. Not industrial, no written policies etc.
 
Status
Not open for further replies.
Top