Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.

Jayson A

macrumors 68030
Original poster
Sep 16, 2014
2,671
1,935
My cat chewed my Mac Pro 5,1 power cord and I wanna put a new one on. Does anyone know what gauge the current cord is? There's no writing on the cable itself, so I have no idea what to use. People say you can use any cord with the same connector, but I'm just trying to be safe.
 
12 AWG is probably enough. 14 AWG is usually rated for 15A at 125V and up to 1500 Watts. Anything beyond that you're pushing the limits and heat comes into play. Some local building codes require not exceeding 1/2 the max rating (when factoring wattage) under typical load.
 
Edit: Isn't the lower the number, the thicker the cord is?

Yes. Just make sure you're buying reputable. There is a difference between the straight and twisted styles when you get to anything more than 14AWG and really need to look at ratings.

Personally rarely find a need for anything more than 14AWG for standard computers on 15A circuits when connected to a properly rated battery backup. Some engineers feel differently.
 
buy a whole new power cord is the best advice.

any gage will work. try 18 gage.

Soft flexible consumer cables are often wire foil wound around a cotton core and you can not repair this stuff. If you must DIY / fix the existing damaged power cord solder the connection. Use thermal shrink tubing, a few layers actually. finally look long hard at the mechanical stability of the fix vs application. short term fix = ok. situation where the mended area is always visible ?= 0k.
 
12 Gauge is definitely over kill, most house wiring for branch circuits are12 gauge. Most table lamps and small appliances are 18 gauge. 16 would be a safe choice.
 
buy a whole new power cord is the best advice.

any gage will work. try 18 gage.

Soft flexible consumer cables are often wire foil wound around a cotton core and you can not repair this stuff. If you must DIY / fix the existing damaged power cord solder the connection. Use thermal shrink tubing, a few layers actually. finally look long hard at the mechanical stability of the fix vs application. short term fix = ok. situation where the mended area is always visible ?= 0k.

He didn't chew right through it but there are bite marks on it. I don't think the cable is damaged internally, but I'm a paranoid person. I figured I could at least get a comparable cable and just replace it easily enough, but I don't know what gauge is currently on there.

One more question. If I find a power cable, how do I know if it's at least a 16AW gauge?
 
If I find a power cable, how do I know if it's at least a 16AW gauge?

Unless it's clearly labeled, measuring thickness with a caliper measurement is the only method. Even that can be "off" depending on the insulation/wrapping around the interior wires.

Depending on who you ask, some electricians say power cables are only "good" for a certain period of time anyway and should be replaced eventually. Some say after 5 years, but most go at least 10 years. Outlets themselves should be replaced after 10-15 years, unless there is premature signs of an issue. Most people do not follow that guidance and it's very cautionary, but that is the general recommendation.
 
?question?
if wire size gets smaller as the gage # increases what is the next largest gage size for 1 gage
 
Nobody actually knows what gauge the current wire is without ripping it open and measuring it? It's not chewed through, it just has bite marks and dents on it. Friggin' dumb cat.
 
My cat chewed my Mac Pro 5,1 power cord and I wanna put a new one on. ...

Replacement cats are readily available at any local animal shelter.

Replacement cords: any properly made cable using the same plugs should be perfectly safe. Any well made cable using 14 guage wire will handle the maximum current load possible out of a standard 15amp wall outlet. Personal computers don't pull enough current to tax 16 guage or even 18 guage for that matter.
 
https://support.apple.com/kb/sp652?locale=en_US

Electrical and operating requirements
  • Line voltage: 100-120V AC or 200-240V AC (wide-range power supply input voltage)
  • Frequency: 50Hz to 60Hz single phase
  • Current: Maximum of 12A (low-voltage range) or 5A (high-voltage range)
  • Operating temperature: 50° to 95° F (10° to 35° C)
  • Storage temperature: -40° to 116° F (-40° to 47° C)
  • Relative humidity: 5% to 95% noncondensing
  • Maximum operating altitude: 10,000 feet
My MP5,1 mid 2012 has Apple A4 13A 125V written on the cable. Believe this cable is 16AWG OEM.
 
I would agree that you should be able to use any standard AC power cord that fits. You can buy these cables at Best Buy or any hardware store. If you really want the OEM cable, though, you can find it here.
 
Nobody actually knows what gauge the current wire is without ripping it open and measuring it? It's not chewed through, it just has bite marks and dents on it. Friggin' dumb cat.

I am no expert so please correct me if wrong but --- wouldn't just wrapping it in a ton of electrical tape be good enough?
 
If the wire shielding has been compromised doesn't that run the risk of a short?
I would show the cat the cord close up.

If the cat is terrified and runs away, its teeth probably touched copper and it got a big surprise - so replace the cord.

If the cat is curious - the insulation is most likely OK.

ps: Power cords are insulated, not shielded (except for a few rare EMF sensitive situations). 50 Hz doesn't need shielding (60 Hz for the colonials).

Shielding is used for high frequency cables.
 
https://support.apple.com/kb/sp652?locale=en_US

Electrical and operating requirements
  • Line voltage: 100-120V AC or 200-240V AC (wide-range power supply input voltage)
  • Frequency: 50Hz to 60Hz single phase
  • Current: Maximum of 12A (low-voltage range) or 5A (high-voltage range)
  • Operating temperature: 50° to 95° F (10° to 35° C)
  • Storage temperature: -40° to 116° F (-40° to 47° C)
  • Relative humidity: 5% to 95% noncondensing
  • Maximum operating altitude: 10,000 feet
My MP5,1 mid 2012 has Apple A4 13A 125V written on the cable. Believe this cable is 16AWG OEM.

Mine says A4 10A 125V on the cable, weird.
 
Mine says A4 10A 125V on the cable, weird.
What year was your machine issued, and is it the OEM cable?
The disparity may be due to measuring peak vs. sustained load.

10 amps at 120 v is about 1200 watts, which has plenty of headroom for the 980w power supplies in the newer cMPs.

If you see 12 amps mentioned, it's likely referring to the peak draw during power-on, which lasts for fractions of a second as capacitors charge. The 12A peak is meaningless for the power cord - since only sustained load will heat up the wires in the cord.

It's entirely reasonable for Apple to say that it needs 12A, and ship it with a 10A cable.
 
The disparity may be due to measuring peak vs. sustained load.

10 amps at 120 v is about 1200 watts, which has plenty of headroom for the 980w power supplies in the newer cMPs.

If you see 12 amps mentioned, it's likely referring to the peak draw during power-on, which lasts for fractions of a second as capacitors charge. The 12A peak is meaningless for the power cord - since only sustained load will heat up the wires in the cord.

It's entirely reasonable for Apple to say that it needs 12A, and ship it with a 10A cable.

Interesting. It’s a mid 2012 model and it’s the original cord. So would a standard 18 gauge work fine then?
 
My MP5,1 mid 2012 has Apple A4 13A 125V written on the cable. Believe this cable is 16AWG OEM.

Mine says A4 10A 125V on the cable, weird.

These are both OEM cables. Apple obviously changed the spec and/or design for some reason at some point, or they needed to meet new UL style codes and compliance.

Here's 14AWG cables that are only $10-$12:
https://www.amazon.com/dp/B005WKJQ4E
https://www.amazon.com/dp/B0012EI6KE

This is basically $4 more than thinner 18AWG, covers all your bases and rated at 15A. Seriously cannot believe this is a full page of discussion now...
 
As an Amazon Associate, MacRumors earns a commission from qualifying purchases made through links in this post.
  • Like
Reactions: koreda
you guys don't need to know the power cord wire gage. There is sooo little current flowing the wire gage is not an issue.

4example:
say you have a large one hp electric motor under rated but heavy load. Its a residential swimming pool pump motor and it will be running over night. The wire gage on the motor stator is quite thin and there is only moderate attention to heat dissipation inside the motor housing. There are millions of motors actively spinning away on the planet why is the OP concerned about wire gage for a wall wort MB charger.

Just to to Amazon and buy anything. Have it over night and move on.
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.