Need additional 220v line?

[spoonman]

Hi gang

I’m looking to add a heat pump to my existing in ground pool but need to figure out how to get power to the unit. For context, the pool equipment is on the opposite side of a 2-story house from the meter.

Is there a way I can tell if I have sufficient service at the pool equipment for the heat pump? I believe my pool pump is running 220v but I’d guess I’d need a second line due to the massive load of a HP.

Is it likely at all the Pb ran double lines for this type of situation? Or possible to fish a 220v line through existing buried conduit? Wishful thinking I know.

 

[PoolGate]

You should have a breaker at the main panel that goes to the pool panel. What size is that breaker? Is there a second breaker labeled to the pool? Heat pumps need around 50 amps.

 

[spoonman]

Just went to the panel. Looks like 2 30amp fuses for the line to the pool. Also found a paper in the fuse box which seems to indicate that they ran 1-240v and 2-110v runs to the pool. Does this make sense? Also, the conduit looks to be only 1/2” (assume this is internal diameter).

 

[spoonman]

Ok, one other thing... I noticed a line for 2-40 amp fuses that run to my cooktop which are locked to “off”. I have a gas cooktop which I plan to stay with meaning this circuit is unused. Coincidentally the cooktop is right next to where the heat pump would go outside.

Can I repurpose the line for the cooktop? How can I tell if this is 240v?

 

[spoonman]

Anyone here have feedback on repurposing a 60 amp circuit for a heat pump?

The circuit was installed by my home builder for an electric kitchen cooktop that was never used.

 

[PoolGate]

Anyone here have feedback on repurposing a 60 amp circuit for a heat pump?

The circuit was installed by my home builder for an electric kitchen cooktop that was never used.

Yes you could re-purpose that line. Keep in mind it is against code to have any hidden junction boxes in case you are needing to extend the cable to outside the house from wherever it is terminated now (the cooktop). 60 amps should be enough for most heat pumps of course just make sure. 220 volt breakers are double pole so it would be double thick and possibly have 2 on/off switches bridged together. Post a pic here of it.

 

[spoonman]

Thanks for the help PoolGate. Here is a picture of the circuit panel and the circuit (actually 80 amps) that I'm hoping to repurpose.

Without violating any code, would I presumably just place a junction box on the outside of the wall with the cooktop outlet so that the box is not hidden? From there it is only 5-10ft max to where the heat pump will be.

 

[PoolGate]

I believe you can put a junction box under your counter where the cooktop resides. I don't think that is considered "hidden". Hidden usually refers to putting it behind drywall.

As far as that circuit, it is a 40 amp 220 volt breaker. 40 amp is the bare minimum for most heat pumps. If you can get a look at the wire and find out what size the wire is, it is possible you could swap out the breaker for a 50 or 60 amp breaker. But that is 100% dependent on the existing wire size. A circuit breaker protects the electrical wire, nothing more, and needs to be sized appropriately for whatever wire you have run. Hopefully someone electrical savvy will chime in but I think you need 8 or 6 gauge wire to be able to handle more than 40 amps.

I didn't look at all heat pumps but you probably could find one that requires a smaller breaker.

@ajw22 any thoughts?

 

[avspin]

If the cooktop is on the same wall I would put a junction box on the exterior wall at the cooktop terminal if there isn't one now. Then pop a hole though the wall (from inside the junction box) to install a sub-panel outside. Nice and clean. But make sure the wires can support the load.

 

[spoonman]

Looks like the 2 models of heat pump I'm looking at require either a min/max breaker size of either 40/60 or 50/60 depending on the unit. Sounds like I could get away with using a 40amp breaker if I go with the smaller pump. Of course I would like to larger so it sounds like I have to research the wire size.

 

[ajw22]

You likely have 6 or 8 gauge wire for the existing 40 amp circuit. As @PoolGate said you need 4 gauge for 60 amps. You might as well run a new line directly from the CB to the HP. Exactly what you need depends on the length of the wire run.

 

[spoonman]

Hi ajw22 - I didn't see anyone reference 4 gauge previously or maybe I missed it. Do you think that is what is needed? Looking around around online it seems the common rule of thumb is 8 gauge at 40 amps, 6 gauge at 50 amps, and 4 gauge at 60 amps. Just want to understand this correctly.

 

[ajw22]

Hi ajw22 - I didn't see anyone reference 4 gauge previously or maybe I missed it. Do you think that is what is needed? Looking around around online it seems the common rule of thumb is 8 gauge at 40 amps, 6 gauge at 50 amps, and 4 gauge at 60 amps. Just want to understand this correctly.

Make sure you are looking at copper wire versus aluminum. And solid versus stranded wire makes a difference. As does length of run.

I am doubtful an electrician used wire on a 40 amp circuit that can be reused on a 60 amp circuit.

 

[swamprat69]

Amperage that a wire can carry also depends on the temperature rating of the wire i.e. 60C vs 75C vs 90C. and the length of the wire rrun. Refer to NEC wire size amperage chart and look for labeling designation on your wire such as thhn or thwn etc. to use in chart.

 

[spoonman]

Thanks for the help everyone. I'm pretty sure I'd like to install the heat pump but have decided to wait until the winter/spring to do the install. Hard to want to spend the money now when my water is 90 degrees and the financial damage of COVID continues to ravage the company where I work.