r/electricians • u/bhokolatebhipbookies • 7d ago

Code question

I’m currently doing my advanced level schooling and I got a code hw question that says “…a 480-240 XFMR has 90°c rated termination, the primary side is fed with RW90XLPE (unjacketed) and the secondary is fed with tw75…”.
If terminations are rated for 90° how can you use a 75 degree insulated conductor?

EDIT: this is based off the CEC

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u/[deleted] 7d ago

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u/bhokolatebhipbookies 7d ago

Thank you, so I would size tw75 using the 75° column and the rw90 using the 90° column in table 2?

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u/danner_tanner 7d ago

Use the 75 degree column. Since the wire is rated for 75 degrees. Another good example you havent thought of is marrettes, they are usually 105-110 degree termination temperature. If termination temp is given consider it. But the wire must match it aswell