Bundling neutrals

[phankins1]

I have a situation where I have a drawing that tells me to connect three neutrals together from three seperately derived systems. What says the code? there is a 480V feed to a Boiler control panel and a control transformer is 480vto 120V for control. There are two boiler control panels and each is fed with a different 480V feed. the drawing shows to take the neutral from each boiler control panel to a lead/lag panel which is feed from another source. connect the three neutrals together to use as control for both boilers.

 

[iwire]

In my opinion that will be a direct violation of 250.24(A)(5)

 

[weressl]

I have a situation where I have a drawing that tells me to connect three neutrals together from three seperately derived systems. What says the code? there is a 480V feed to a Boiler control panel and a control transformer is 480vto 120V for control. There are two boiler control panels and each is fed with a different 480V feed. the drawing shows to take the neutral from each boiler control panel to a lead/lag panel which is feed from another source. connect the three neutrals together to use as control for both boilers.

The last time I heard about bundling was associated with the mortgages of the recent economic avalanche. Now THAT did not turn out to good, did it?

 

[zinc]

Are they grounded? It seems like they end up tied together anyway! I think the thing to be careful of is the 120 hots! If they are not phased together, any panel interconnection could cause fireworks.