I'm having my HVAC replaced and am moving the location of the 2 outside compressors in the process.

Is there a way to feed them from a single line and larger breaker, or do I need to run two separate #10/3 lines on 240v 30a breakers? Like a multi-unit disconnect?

Just thinking of the cost involved with the double lines, as the units will be on the opposite end of the house from my service panel(of course).

Good morning,

The installation instructions (Electrical Connections) will tell you that answer. I'm really surprised that the contractor doing the installation cannot answer this question

Things to consider, first, if the installation instructions calls for the use of dedicated circuits then you cannot place each A/C unit on one single circuit.

If there are no instructions on the connection then you would have to size the circuit to have the capacity you need. Then you have to order the proper breaker and make sure you main service panelboard or add-on panelboard can accommodate such a breaker.

Just for example, if you have a 200 amp service and you 175 amps to go to the new circuit, then your panelboard may not use that size breaker but some other company's panelboard might allow that breaker. By the way, I'm only using random number to illustrate a point.

I see no reason you couldn't run a heavier cable and use a rain tight sub panel for a disconnect. But the cost of material will probably be more than two individual lines.


Or do I need to run two separate #10/3 lines on 240v 30a breakers?

Why 10/3, does installation require 10/3 or 10/2?

AC compressors use 240 volts, so a 3 conductor cable is required.
Pricing out the exterior subpanels defeats the purpose as they are way more than the cost of the two cables.
I'll just run two individual lines with separate disconnects.

Red,

You are incorrect. 240 V only requires 2 conductors and a bare or insulated ground.

If either A/C unit needs to have a 120 V present, then you would need a 3 conductor cable with a bare or insulated ground.

Also, just as a heads up, you need to have a GFCI protected 120 V receptacle within 25' of both units for service and maintenance proposes. I normally use a 20 Amp circuit for this.

donf - you're right I didn't write clearly.

I had 10/3 on the brain as I was wiring in generator inlet panels this past weekend.