NEC 430.52 (3) Exception No. 2 "permitted to be increase to the value marked on controller"

[MikeBlackwell]

How would we understand the "increase to the value marked on the controller" in the exception closing statement? What markings on controller is this referring to? In order to make sense to me it must mean the MCP in the listed controller can be increased. If the applications if technically lower in ratings and it is a listed controller it can be set to exceed the allowable 800% per that exception if not greater than 15A . Not finding much on this particular exception and the following is needing to be confirm.

Looking at using a UL listed controller with size 1 starter and 15A HMCP for a motor rated 1.5HP, 480V motor 3A FLC. The minimum setting is 45A on the magnetics of the 15A HMCP. The exception would seem to allow this but the statement to be increased to the value marked on the controller is confusing term. why not say breaker?

How would the FLA range for the HMCP 15A play into this exception which is 3.4-4.5A. it would seem NEC is taken exception to this factor in allowing for motors less then 8A?

Any insights to this exception and the meaning of that phrase would be much appreciated.

 

[tortuga]

Are you on the 2020 NEC? You are probably referring to 430.52(C)(3), which only applies to a Motor circuit Protector (MCP) for small motors 8A or less meeting the requirements of (C)(3)

How would we understand the "increase to the value marked on the controller" in the exception closing statement?

Where the full load current of the motor is 8A or less and the controller is 15A or less you can set the controller to max.

What markings on controller is this referring to?

The continuous current rating marked on the controller can be turned up to max if 15 amps or less.

 

[MikeBlackwell]

thank you for your reply! I may be getting lost in the weeds. the wording "the current rating of the controller" is suggesting something outside of the breaker adjustment but then there is nothing else that can be changed within the controller regarding branch protection other than the MCP dial setting within once you are at 15A rating. As we cannot modify a controller voltage or HP ratings as this is UL listed so we are talking the breaker within as the device being adjusted. What I have is a sz 1 controller that is UL listed and has within a 15A HMCP breaker. I want to use the controller for a 3A load and would set the magnetics on the breaker to "A" setting which is 45A. this is above the 1300% allowed per NEC for other than design B energy-efficient motors. Are we okay to still use based on that fact? I would like to assume the exception to go to a 15A breaker is allowing as well and would not be a violation of NEC 430:51 (C) (3) and (7) code as a result. thanks for taking the time to reply!!

 

[tortuga]

Well, I am no expert best thing would be for Jref to chime in.
But, yes 430.52 is just short circuit and ground fault protection.
How is the unit providing / sizing your overload protection in 430.32(1)?
Heaters?
Seems to me you'd need more like a NEMA Size 0.