Conduit or no?
#1
Member
Thread Starter
Join Date: Sep 2019
Posts: 9
Upvotes: 0
Received 0 Upvotes
on
0 Posts
Conduit or no?
I will be running 10/3 cable around 30 feet to a VFD for a CNC (30 amps). I usually run regular 120 volt cables in conduit but was told by someone that you shouldn't run 10/3 (240 volt) in conduit because of temperature issues.
Is this true and is it against code, or is it OK to run the 10/3 inside some conduit?
As a side note I usually use Carlon non-metallic conduit if it makes any difference.
https://www.amazon.com/Carlon-Electr.../dp/B00FY3MUUQ
Is this true and is it against code, or is it OK to run the 10/3 inside some conduit?
As a side note I usually use Carlon non-metallic conduit if it makes any difference.
https://www.amazon.com/Carlon-Electr.../dp/B00FY3MUUQ
#2
It is not against code to sleeve NM cable in conduit as longs as some rules are followed.
The conduit must be sized large enough for the installed cables. This doesn't mean that the cable fits in the conduit. The cable cannot take up more than 40% of the conduit fill with 3 or more wires. For flat cables, the diameter is measured by the largest size. All this is to prevent heat buildup.
The conduit, if metallic, is required to be bonded to the equipment ground. In most cases this is done using metal boxes that the conduit attaches to.
Besides the items above installing cable in conduit can be difficult. The conduit needs to be fully installed before installing the wires and the outside jacket of the cable may not be removed.
The conduit must be sized large enough for the installed cables. This doesn't mean that the cable fits in the conduit. The cable cannot take up more than 40% of the conduit fill with 3 or more wires. For flat cables, the diameter is measured by the largest size. All this is to prevent heat buildup.
The conduit, if metallic, is required to be bonded to the equipment ground. In most cases this is done using metal boxes that the conduit attaches to.
Besides the items above installing cable in conduit can be difficult. The conduit needs to be fully installed before installing the wires and the outside jacket of the cable may not be removed.
#3
Member
Thread Starter
Join Date: Sep 2019
Posts: 9
Upvotes: 0
Received 0 Upvotes
on
0 Posts
The conduit must be sized large enough for the installed cables. This doesn't mean that the cable fits in the conduit. The cable cannot take up more than 40% of the conduit fill with 3 or more wires. For flat cables, the diameter is measured by the largest size.
#5
The NEC says that one wire (or cable) can use 53% of the area.
That would mean that 3/4" conduit would be OK to use with 10/3, correct