Transformer disconnect

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yankeeman411

Member
Location
nj
Quick question guys, i have a 208/120 feed to a step up transformer to 277/480. The 480 is needed for a elevator controler locator in a machine room 5 floors up. The print calls for a disconnect in the machine room near the controller room. Do i also need to put a disconnect near the transformer on the secondary side. The panel feeding the transformer is 15 ft away, do i need a disconnect on the primary or is the panel sufficient?
 

augie47

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Staff member
Location
Tennessee
Occupation
State Electrical Inspector (Retired)
As far as the primary, 450.14 accepts an "in sight from" disconnect.
As far as the secondary, see 240.21(C). With a 480/277 secondary, you will need to comply with the 240.21(C) secondary rules. Most commonly the 25ft rule is applicable.

(sorry ron..typing at the same time)
 
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