Is 6 gauge wire big enough for a 60 amp upgrade?

[ummgood]

So I was having my NEMA 14-50 installed for my model 3 last week. The electrician (who is a master level in Texas) told me that the 6 gauge wire that he was installing was big enough for increasing my breaker to 60A. I'll only do this if I buy a Tesla Wall Charger so I could set it at 48Amp continuous. I have about 30 feet of wire going to my attic in a conduit outside which are individual wires. Then in the attic in a junction box the 30 feet is connected to about 95 feet of romex going to my garage. So about 125 feet total.

I just want to make darn sure that if I change the breaker out that it will handle the extra current.

 

[ABC2D]

Based on Paige Irrigation & Lighting Division you need 3 AWG

 

[PJFW8]

Based on Paige Irrigation & Lighting Division you need 3 AWG

View attachment 277123

You show 120 volts. What is it at 240? Is this for "Romex" or wires in conduit?

 

[Haxster]

Looks marginal.

A nice calculator at: Wire Size Calculator

Power loss calculator at: www.cirris.com/learning-center/calculators/133-wire-resistance-calculator-table

You can use the formula (Current squared times Resistance) to see how much power (by wire heating) is lost in the wiring.

 

[GWord]

Gauge isn't the only design consideration but assuming that all your wire is 90degC rated and you have no unusual circumstances like wet installation, high temp de-rates or full conduits, it could support 60amp or more. If you are not qualified to uprate the branch or are unsure, consult a professional obviously.

 

[azdryheat]

For 240V 3 phase it shows 4 AWG copper 3AWG aluminum. I have a NEMA 14-50 (50 amp) with about 85 foot run. Used 4 AWG copper. Also, I think mine is only rated to 50A. Possible there is a 60 amp version, but I would check.

 

[ummgood]

Below the calculator it says the draw of the device so in this case it would be 48Amp correct? With that and 240 single phase and a 3Volt drop it says it can be done on 6 gauge copper.

I am comfortable changing out breakers so that isn't a big deal and I did ask the guy who is a licensed professional. I just wanted people's input on it. I can check the wiring to see what the temp rating is on it.

 

[BerTX]

I'm not an electrician and you need to consult one.

The wire in the conduit is fine, The Romex is not. If the entire run was in conduit, you'd be fine.

 

[mongo]

Your electrician is correct. 6 AWG NM-B is rated 55 Amp @ 60 degree C (most conservative). 55 not being a common breaker allows increase to 60A. Actual load is 48 Amps.

From the Paige page:

 

[ummgood]

Thanks! That is what I plugged in. I just wanted to double make sure. The guy seemed to know what he was talking about.

I think I'll probably be buying a mobile connector then. This allows me the fastest charge I can get if I need it for some occasion.

 

[MorrisonHiker]

Thanks! That is what I plugged in. I just wanted to double make sure. The guy seemed to know what he was talking about.

I think I'll probably be buying a mobile connector then. This allows me the fastest charge I can get if I need it for some occasion.

I think you mean wall connector, not mobile connector. You had it right in the original post.

Another benefit of the wall connector is that you can install multiple wall connectors and link them all together and they will balance the load, allowing you to charge multiple cars at once. We currently have two 14-50 outlets but will be adding 2 or 3 wall connectors this year, once we receive them from the referral program.

 

[ummgood]

I think you mean wall connector, not mobile connector. You had it right in the original post.

Another benefit of the wall connector is that you can install multiple wall connectors and link them all together and they will balance the load, allowing you to charge multiple cars at once. We currently have two 14-50 outlets but will be adding 2 or 3 wall connectors this year, once we receive them from the referral program.

Thanks for correcting me. You are right. I just realized that the Model 3 LR can only charge at 40A. So I don't need to upgrade my breaker currently. Maybe if I get another Tesla in the future I'll get another wall connector and then upgrade the circuit at that point.

 

[MorrisonHiker]

Thanks for correcting me. You are right. I just realized that the Model 3 LR can only charge at 40A. So I don't need to upgrade my breaker currently. Maybe if I get another Tesla in the future I'll get another wall connector and then upgrade the circuit at that point.

Hmm. I thought the Model 3 SR was limited to 32 amps but that the Model 3 LR has 48 amp charging. It is only limited to 40 amps on a 14-50 outlet since that's the max a mobile connector provides. The wall connector should allow 48 amp charging.

 

[ummgood]

Hmm. I thought the Model 3 SR was limited to 32 amps but that the Model 3 LR has 48 amp charging. It is only limited to 40 amps on a 14-50 outlet since that's the max a mobile connector provides. The wall connector should allow 48 amp charging.

Oh ok I was reading the presskit which states that the LR model has this:

Long Range Battery - $9,000

• Range: 310 miles
• Supercharging rate: 170 miles of range per 30 minutes
• Home charging rate: 37 miles of range per hour (240V outlet, 40A)
• 0-60 mph: 5.1 seconds
• Top speed: 140 mph
• Deliveries begin: July 2017

 

[MorrisonHiker]

Oh ok I was reading the presskit which states that the LR model has this:

Long Range Battery - $9,000

• Range: 310 miles
• Supercharging rate: 170 miles of range per 30 minutes
• Home charging rate: 37 miles of range per hour (240V outlet, 40A)
• 0-60 mph: 5.1 seconds
• Top speed: 140 mph
• Deliveries begin: July 2017

Yeah. With a "240v outlet" (meaning NEMA 14-50), it is limited to 40 amps. If you have a hard-wired WC then it could handle 48 amps.

Notice how it shows 48 amps on the screen:

 

[Robotpedlr]

@ummgood your initial post states you are using a 14-50 plug. That is only rated to 50 amps...so you probably dont want to use a 60amp breaker with that plug. The breaker should not be higher than the plug (or wire) rating. The breaker should be the weakest link (so it trips before something fries).

 

[brkaus]

My understanding -
NEMA 14-50 with now included Gen 2 UMC - 32A
NEMA 14-50 with old Gen 1 UMC - 40A
HPWC (set at 60A or more) - 48A

 

[LCR1]

You show 120 volts. What is it at 240? Is this for "Romex" or wires in conduit?

Amps don't care about volts. 100 amps @120 requires the same wire size as 100amps @ 240v


#6 If using romex(nm) wire you're limited to 55amp draw. If using THHN 75* type wire you'll get 65amps 75 amps from 90* thhn-2

 

[mongo]

@ummgood your initial post states you are using a 14-50 plug. That is only rated to 50 amps...so you probably dont want to use a 60amp breaker with that plug. The breaker should not be higher than the plug (or wire) rating. The breaker should be the weakest link (so it trips before something fries).

They know

I'll only do this if I buy a Tesla Wall Charger so I could set it at 48Amp continuous.

 

[mongo]

Amps don't care about volts. 100 amps @120 requires the same wire size as 100amps @ 240v


#6 If using romex(nm) wire you're limited to 55amp draw. If using THHN 75* type wire you'll get 65amps 75 amps from 90* thhn-2

If you are looking at total power loss or heating that is true (max current capacity of a wire). When based on percentage voltage drop, 240V has twice the allowable drop as 120V. So you can use a smaller gauge rated for the current, and meet code and voltage specs.

Edit: temperature rating is to handle environmental conditions (higher temp locations/ lamp fixtures can require higher rated wire insulation). Most terminals are only rated to the 60 or 75 C values..