HVAC wiring and breakers

   / HVAC wiring and breakers #1  

czechsonofagun

Elite Member
Joined
Jun 23, 2006
Messages
3,527
Location
Old Dominion
Tractor
Kubota B1750
I am reading up on my future project and here is a question on wires. This is what I can understand from resources I found:

Air handler - 240V, double breaker - provides power to the blower and circuit boards (2+1 romex, based on the current, #10 should be enough)

Emergency heat strip - 240V, double breaker - separate wire and breaker - provides power to the heating element (2+1 romex, sized by the heating element, #6 for 10KW)

Heat pump - 240 V, double breaker - provides power to the whole heat pump (2+1 romex #8)


The signal wiring (18gauge, 6 or more strand wire) goes from heat pump to air handler and from air handler to the thermostat.


Do I understand it correctly? Or is there a need for a 0 wire for the air handler? I have the space on my panel, but technically I could have a subpanel next to the air handler and distribute the power from there.
 
   / HVAC wiring and breakers
  • Thread Starter
#3  
Oops. that's czechism. We call minus wire 0 - say in electrical outlet you have the phase (+) and 0 (-). Sorry :)

Anyway, up here we distinguish 240V with and without negative - water heater is connected by 2+1 (two power wires and ground) but electrical stove has 3+1 (two power wires, negative and ground - since it needs 120V for the display and owen lights)
 
   / HVAC wiring and breakers #4  
Whats the amp draw?
 
   / HVAC wiring and breakers #5  
Normally if it says 240V, it's 2w+gnd. 240/120V is 3w+gnd. Put in what the manual for the AH says. The 3rd wire is neutral, not a negative.
 
 
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