NM cable temperature installation.

[nizak]

I’m looking to bid 2 new homes that will be in the rough in stage in January.

It’s not uncommon to have 0 degree nights and highs for daytime only in the low teens where I’m at.
Sites will have some form of temp heat but there will be no insulation in place at time of rough in to contain it.

I would like to include wording in the proposals that states work may need to cease due to the cold temps.

What temperature does it become dangerous to install NM cable ?

Seems that 15 degrees is a number I recall but can’t find anything to support that.

Thanks

 

[augie47]

Per Southwire:
Southwire's Romex® SIMpull ® NMD90 cables may be used for both exposed work in dry locations or concealed work in dry or damp locations. The maximum allowable conductor temperature is 90°C. The minimum recommended installation temperature is -25°C for two-conductor cables and -10°C for three-conductor cables (with suitable handling procedures). Material should be properly stored above 0°C for 24 hours prior to installation. The maximum voltage rating for all intended applications is 300 volts. Consult the Canadian Electrical Code1 for further information related to applications.

 

[James L]

Per Southwire:
Southwire's Romex® SIMpull ® NMD90 cables may be used for both exposed work in dry locations or concealed work in dry or damp locations. The maximum allowable conductor temperature is 90°C. The minimum recommended installation temperature is -25°C for two-conductor cables and -10°C for three-conductor cables (with suitable handling procedures). Material should be properly stored above 0°C for 24 hours prior to installation. The maximum voltage rating for all intended applications is 300 volts. Consult the Canadian Electrical Code1 for further information related to applications.

Wow, that's low
-25C is -13F

I've tried to install NM at -12F and it was breaking the sheath.

One thing to consider is not only pulling it, but stripping and making up after it's been in the walls for days.

I won't install it if temp is under 10F

 

[letgomywago]

Don't leave the wire overnight

Get a diesel torpedo heater

Increase rough in time

Put in a clause that if the weather is bellow X they'll either need to delay or provide heat or pay extra so you can do the above.

 

[Dennis Alwon]

I can tell you from experience that temps in the low 20's and teens are no fun to work with nm cable. I remember installing cat 3 cable and when I used a staple gun the entire outer jacket would shatter. This didn't happen with NM but it was difficult to work in those temps.

 

[retirede]

Isn’t NMD90 exclusively Canadian wire? Our NM may be different.

 

[CoolWill]

Isn’t NMD90 exclusively Canadian wire? Our NM may be different.

I think the only real difference is that Canadian NM doesn't have the cardboard inside. It may only be 300 volt rated as well

 

[retirede]

I think the only real difference is that Canadian NM doesn't have the cardboard inside. It may only be 300 volt rated as well

That’s what I’ve always thought, too. Until this thread. Now I wonder about low-temp performance. Why would the Southwire note above mention only the Canadian type?

 

[Fred B]

the colder it is the worse it is to try to manipulate a cable or wire not to mention issues with fingers getting cold as some work is really difficult even with light weight gloves let alone heavy insulated cold weather gloves.
Had to install a repair to a service and splicing and bending a 250mil at 20 below was a bear, took waaay longer than it would otherwise.
So I would say bidding for cold weather work add an adjustment to time for that. Or include the cost of portable heat to be piped into the building. Milwaukee makes a portable propane salamander heater works off a M18 battery, it will definitely get even an uninsulated space more comfortable to work in.