HVAC Wiring

[charp]

The HVAC unit (LP gas furnace) is made by Bryant around 1990 and was wired with a flat, black insulated wire with two 8 gauge conductors and a small ground. Shouldn't it be wired with 8/3 with ground? I have to remove some decking to access the disconnect box mounted on the wall by the unit to see what kind of wire runs between the unit and the disconnect box. Yes, some bright person actually built a deck right over the unit and covered the shutoff box! I should post a picture of the original Zinsco subpanel to really scare y'all.

[Chad Schloss]

if you are talking about an a/c unit that is run off of 220v, all you need is two wire w/ground since the neutral is not used.

[charp]

It's an all in one unit, AC/gas furnace/fan, installed outside the house. I have some 8/3 that I can use to reach the new subpanel, I just won't use the neutral. Thanks

[jadnashua]

The installation manual would indicate if it needs a neutral (which would allow some internal 120vac circuits/devices), but it probably doesn't need it.