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_i...tml#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.