NEC Question - Maintenance Disconnect

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Cinic

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Jul 24, 2015
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Tempe, AZ
I was doing some reading on the NEC prompted by another thread here in the pumping station. Feel free to move this post if it is better placed elsewhere.

NEC 680.12 requires a means of disconnecting power to equipment for maintenance. I cannot find what is considered 'means'. For this example, let's consider a 240 V pump motor wired in with a T104R mechanical timer. I have some questions:
  • Is the manual switch inside a timer box considered adequate? I'd think not as it could activate itself.
  • Is a properly rated and installed DPST switch wired in either before or after the timer adequate?
  • Is a pull out disconnect (like would be used on a residential heat pump) adequate? Overkill?
  • Is the timer itself considered pool equipment that should have a disconnect?
  • If the timer does require a disconnect, can it use the same disconnect as for the motor it's controlling?

Below is my current setup that I'm having reworked to make more adequate and add in another timer for my water feature pump.



The three boxes below the timer each have a switch. I don't know if they're SPST or DPST. I do know that either of the bottom two switches will turn off the water feature pump. My guess is that each switch is a SPST switch on one of the hots.

The top switch will turn off the main pump. This could be a DPST switch on both the hots or just a SPST cutting one of them. If it's just a SPST, there is currently no means of disconnecting both legs w/o flipping the breaker.

I don't plan on doing this work myself, but want to understand the code and what an electrician may do.

While digging around, I did find this post which seems to answer quite a bit. http://www.inspectionnews.net/home_...-timer-switch-pool-disconnect.html#post187284

In addition, the sub-panel supplying this area does not have GFCI breakers for the pump motors. I don't believe this was required at the time of install back in the 90s. But it is now.

Thanks for any input - happy to answer any questions.
 
Well, I'm not an electrician, don't play one on TV and didn't sleep at a Holiday Inn Express last night...... Take my comments for what you paid.

Most electricians. unless they do pool/spa work regularly have no idea of Art 680 of the NEC. Just your asking questions here and doing a little research is going to put you ahead of them.

As ot means, a switch or the ability to trip a breaker at that spot will usually suffice as the "means".

Is the manual switch inside a timer box considered adequate? I'd think not as it could activate itself. I agree with you , no.
Is a properly rated and installed DPST switch wired in either before or after the timer adequate? Yes, but AI would select after the timer so you don't have to reset the time
Is a pull out disconnect (like would be used on a residential heat pump) adequate? Overkill? Overkill
Is the timer itself considered pool equipment that should have a disconnect? I don't think so
If the timer does require a disconnect, can it use the same disconnect as for the motor it's controlling? N/A

My go to guy for pool electric is Mike Holt who teaches classes about the NEC. Here is his answer to this question Stumped By the Code? Requirements for Installing Maintenance Disconnect at a Pool, Acceptable Wiring Methods for Class I Locations, and More
 
I generally agree with Tim's responses above.

But where are the breakers for all of this? Most pool pads that I see have a subpanel within sight of the equipment and it has six or less breakers so the subpanel acts as the disconnect. If your subpanel (I'm assuming here) is within view of the equipment and has six or less breakers then it is the disconnect.

From a safety standpoint what you have is confusing at best. If you want to spend some time and money here I would install a subpanel (if there is not one already) to act as the disconnect and run all of this from the subpanel. Then if something happens or someone else needs to do maintenance its clear what the disconnect is.

If you just add a switch all you are doing is making the situation more confusing. Even labeling only marginally improves the situation.
 
Comments inserted below.

Cinic said:
NEC 680.12 requires a means of disconnecting power to equipment for maintenance. I cannot find what is considered 'means'. For this example, let's consider a 240 V pump motor wired in with a T104R mechanical timer. I have some questions:

  • Is the manual switch inside a timer box considered adequate? I'd think not as it could activate itself. The fact that it normally only breaks one leg would preclude if from being the means of disconnect.


  • Is a properly rated and installed DPST switch wired in either before or after the timer adequate? Technically yes. Wire it before the timer.


  • Is a pull out disconnect (like would be used on a residential heat pump) adequate? Overkill? I'll differ from the previous posts here. I think a pull out disconnect (or lockable switch) is a great means of meeting the code. While a switch technically meets code, using a pull-out or lockable switch ensures that if you're performing maintenance on the equipment you can positively disconnect power from the equipment. With the pull-out you can just stick the cartridge in your pocket and that ensures no-one can re-energize the power.


  • Is the timer itself considered pool equipment that should have a disconnect? If you take the code literally, the disconnect should be before the timer. It states that pretty much everything except lighting should have a means of disconnect.


  • If the timer does require a disconnect, can it use the same disconnect as for the motor it's controlling? It can if the power supplying the timer is the same power supplying the motor.

...

The three boxes below the timer each have a switch. I don't know if they're SPST or DPST. I do know that either of the bottom two switches will turn off the water feature pump. My guess is that each switch is a SPST switch on one of the hots. Those switches were most likely installed in an attempt to meet the disconnect code, and technically they do as long as they break both hot legs.
Click to expand...
 
gwegan said:
I generally agree with Tim's responses above.

But where are the breakers for all of this? Most pool pads that I see have a subpanel within sight of the equipment and it has six or less breakers so the subpanel acts as the disconnect. If your subpanel (I'm assuming here) is within view of the equipment and has six or less breakers then it is the disconnect.

From a safety standpoint what you have is confusing at best. If you want to spend some time and money here I would install a subpanel (if there is not one already) to act as the disconnect and run all of this from the subpanel. Then if something happens or someone else needs to do maintenance its clear what the disconnect is.

If you just add a switch all you are doing is making the situation more confusing. Even labeling only marginally improves the situation.
Click to expand...

There is a pool sub-panel mounted to the house about 20' behind from where the photo was taken. There is also a 4' screen wall between the equipment and the panels. If you're standing everything is within sight. If you're kneeling and working at the equipment you can't see the breaker panel. The conductors run underground in conduit to where you see them emerge from the earth. I don't know if that panel can act as the disconnect as currently setup.

Each motor is run on separate breakers and there's another breaker for the pool light. I also believe the GFCI outlet by the equipment is on the same circuit as the pool light. Not sure if that meets code or not.

I did some digging around the wiring last night. Each of the switches is a DPST switch that breaks both conductors. So there are two controlling the water feature pump. There is an old X10 switch (don't have a remote) controlling the pool light. My guess is that there was also an X10 switch for the water feature that went bad and was replaced with a redundant DPST switch. I think removing the redundant switch (and making that box a simple j-box) would greatly simplify the area. I'd have two switches, each before the timer controlling the motor in question.

My short term goal here was to get the water feature pump on a timer to automate chlorinated water flow. Right now it's on me to flip the switch(es) daily...and that But I wanted to be sure that I understood code requirements and didn't have anything new done incorrectly and at the same time fix anything that was blatantly wrong.

Thanks for the insight guys. Additional comments welcome if you have any.
 
A timer would not be considered to be a disconnecting means.

The breaker in sub panel 20' away should be sufficient. Since you would disconnect power before kneeling down at the pump I don't see any concern about the wall

From NEC:

In Sight From (Within Sight From, Within Sight).
Where this Code specifies that one equipment shall be “in
sight from,” “within sight from,” or “within sight of,” and so
forth, another equipment, the specified equipment is to be visible
and not more than 15 m (50 ft) distant from the other
 
If one is installing a hot tub serviced with 220vac thru a local GFCI (Square d spa pack for instance) is the GFCI breaker being turned off a maintenance disconnect? It’s seperation requirements from the water surface are same as for a “disconnect”. The GFCI interrupts both the red and black legs of the 220.
 

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Does it meet the requirements for the disconnect?
1. Readily accessible.
2. Within sight of the equipment. [“Within sight” means it's visible and not more than 50 ft from one to the other.]
3. At least 5' from the water unless separated by a barrier.

If it meets all those requirements, then it meets the NEC requirements of a disconnect.

Having said that. I prefer a pull-out or lockable disconnect. That way you know someone isn't going to come by and turn it on when you're not looking.
 
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