Wisconsin AHJ: Fan Disconnects

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ptonsparky

ptonsparky

Tom
Location
NE (9.06 miles @5.9 Degrees from Winged Horses)
Occupation
EC - retired
I am trying to get some Manual Motor starters installed ahead of fans in a dairy. The new manager tells me the fans they had installed in a Wisconsin dairy never had them. How did they get by with it? For me, one contactor will start a section of fans. In this case 28 - 1.5 HP fans for each of three groups.

Am I missing something that would allow no SC and OC protection for these motors?
 
ptonsparky said:
I am trying to get some Manual Motor starters installed ahead of fans in a dairy. The new manager tells me the fans they had installed in a Wisconsin dairy never had them. How did they get by with it? For me, one contactor will start a section of fans. In this case 28 - 1.5 HP fans for each of three groups.

Am I missing something that would allow no SC and OC protection for these motors?
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Farms are not required to be inspected (yet) in Wisconsin so it just could have been that. Could they have been single phase fans?
 
ptonsparky said:
Three phase, but no inspection would account for it. I thought Wisconsin was a step ahead of us.
Click to expand...

We are still on the 2011 NEC for one and two family dwellings until 1/1/20. 2017 for everything else.
Farm electrical inspections will be required starting 1/1/20.
 
Short circuit protection always. There is no way around this.

I have seen some group protection schemes where you have one MCP covering multiple motors on one machine but it still needs multiple overload protection somehow which with MMS being so cheap is not really economical.

Overcurrent is not required in some minor cases. Among others I remember motors with integral thermal protection and fire pumps, but fire pumps have additional rules where everything is sized to allow it to stall without burning up the wiring. So overcurrent relays aren’t required because it is not needed.



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