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@@ -53,111 +53,78 @@ Conductor application and insulation shall comply with Table 311.10(A).
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##### Table 311.10(A) Conductor Application and Insulation Rated 2001 Volts and Higher
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| Trade Name | Type Letter | Maximum Operating Temperature | Application Provision | Insulation | Outer Covering |
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| ------------------------------- |:----------------:|:-----------------------------:| --------------------- | ------------------------------ | ------------------------ |
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| Medium voltage solid dielectric | MV-90<br>MV-105* | 90°C<br>105°C | Dry or wet locations | Thermoplastic or thermosetting | Jacket, sheath, or armor |
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| Trade Name | Type Letter | Maximum Operating Temperature | Application Provision | Insulation | Outer Covering |
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|:-------------------------------:|:-------------------:|:-----------------------------:|:---------------------:|:------------------------------:|:------------------------:|
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| Medium voltage solid dielectric | MV-90 | 90°C | Dry or wet locations | Thermoplastic or thermosetting | Jacket, sheath, or armor |
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| | MV-105<sup>\*</sup> | 105°C | | | |
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\*Where design conditions require maximum conductor temperatures above 90°C.
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<sup>\*</sup>Where design conditions require maximum conductor temperatures above 90°C.
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#### 311.10(B) Thickness of Insulation and Jacket for Nonshielded Insulated Conductors.
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Thickness of insulation and jacket for nonshielded solid dielectric insulated conductors rated 2001 volts to 5000 volts shall comply with Table 311.10(B).
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Thickness of insulation and jacket for nonshielded solid dielectric insulated conductors rated 2001 volts to 5000 volts
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shall comply with Table 311.10(B).
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##### Table 311.10(B) Thickness of Insulation and Jacket for Nonshielded Solid Dielectric Insulated Conductors
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##### Table 311.10(B) Thickness of Insulation and Jacket for Nonshielded Solid Dielectric Insulated Conductors Rated 2001 Volts to 5000 Volts
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Rated 2001 Volts to 5000 Volts
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Overall Insulation Jacket
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Dry Locations Single Conductor Without Jacket 8 2.79mm (110mils)
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Dry Locations Single Conductor Without Jacket 6 2.79mm (110mils)
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Dry Locations Single Conductor Without Jacket 4–2 2.79mm (110mils)
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Dry Locations Single Conductor Without Jacket 1–2/0 2.79mm (110mils)
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Dry Locations Single Conductor Without Jacket 3/0–4/0 2.79mm (110mils)
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Dry Locations Single Conductor Without Jacket 213–500 3.05mm (120mils)
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Dry Locations Single Conductor Without Jacket 501–750 3.30mm (130mils)
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Dry Locations Single Conductor Without Jacket 751–1000 3.30mm (130mils)
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Dry Locations Single Conductor Without Jacket 1001–1250 3.56mm (140mils)
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Dry Locations Single Conductor Without Jacket 1251–1500 3.56mm (140mils)
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Dry Locations Single Conductor Without Jacket 1501–2000 3.56mm (140mils)
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Dry Locations Single Conductor 8 2.29mm (90mils) 0.76mm (30mils)
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Dry Locations Single Conductor 6 2.29mm (90mils) 0.76mm (30mils)
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Dry Locations Single Conductor 4–2 2.29mm (90mils) 1.14mm (45mils)
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Dry Locations Single Conductor 1–2/0 2.29mm (90mils) 1.14mm (45mils)
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Dry Locations Single Conductor 3/0–4/0 2.29mm (90mils) 1.65mm (65mils)
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Dry Locations Single Conductor 213–500 2.29mm (90mils) 1.65mm (65mils)
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Dry Locations Single Conductor 501–750 2.29mm (90mils) 1.65mm (65mils)
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Dry Locations Single Conductor 751–1000 2.29mm (90mils) 1.65mm (65mils)
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Dry Locations Single Conductor 1001–1250 2.92mm (115mils) 1.65mm (65mils)
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Dry Locations Single Conductor 1251–1500 2.92mm (115mils) 2.03mm (80mils)
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Dry Locations Single Conductor 1501–2000 2.92mm (115mils) 2.03mm (80mils)
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Wet or Dry Locations Single Conductor 8 3.18mm (125mils) 2.03mm (80mils)
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Wet or Dry Locations Single Conductor 6 3.18mm (125mils) 2.03mm (80mils)
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Wet or Dry Locations Single Conductor 4–2 3.18mm (125mils) 2.03mm (80mils)
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Wet or Dry Locations Single Conductor 1–2/0 3.18mm (125mils) 2.03mm (80mils)
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Wet or Dry Locations Single Conductor 3/0–4/0 3.18mm (125mils) 2.41mm (95mils)
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Wet or Dry Locations Single Conductor 213–500 3.56mm (140mils) 2.79mm (110mils)
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Wet or Dry Locations Single Conductor 501–750 3.94mm (155mils) 3.18mm (125mils)
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Wet or Dry Locations Single Conductor 751–1000 3.94mm (155mils) 3.18mm (125mils)
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Wet or Dry Locations Single Conductor 1001–1250 4.32mm (170mils) 3.56mm (140mils)
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Wet or Dry Locations Single Conductor 1251–1500 4.32mm (170mils) 3.56mm (140mils)
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Wet or Dry Locations Single Conductor 1501–2000 4.32mm (170mils) 3.94mm (155mils)
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Wet or Dry Locations Multiconductor Insulation* 8 2.29mm (90mils)
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Wet or Dry Locations Multiconductor Insulation* 6 2.29mm (90mils)
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Wet or Dry Locations Multiconductor Insulation* 4–2 2.29mm (90mils)
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Wet or Dry Locations Multiconductor Insulation* 1–2/0 2.29mm (90mils)
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Wet or Dry Locations Multiconductor Insulation* 3/0–4/0 2.29mm (90mils)
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Wet or Dry Locations Multiconductor Insulation* 213–500 2.29mm (90mils)
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Wet or Dry Locations Multiconductor Insulation* 501–750 2.29mm (90mils)
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Wet or Dry Locations Multiconductor Insulation* 751–1000 2.29mm (90mils)
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Wet or Dry Locations Multiconductor Insulation* 1001–1250 2.92mm (115mils)
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Wet or Dry Locations Multiconductor Insulation* 1251–1500 2.92mm (115mils)
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Wet or Dry Locations Multiconductor Insulation* 1501–2000 3.56mm (140mils)
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Conductor
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Size
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(AWG or kcmil)
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Dry Locations, Single Conductor Wet or Dry Locations
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Without Jacket
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Insulation
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With Jacket Single Conductor Multiconductor
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Insulation*
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Insulation Jacket Insulation Jacket mm mils mm mils mm mils mm mils mm mils mm mils
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8 2.79 110 2.29 90 0.76 30 3.18 125 2.03 80 2.29 90
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6 2.79 110 2.29 90 0.76 30 3.18 125 2.03 80 2.29 90
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4–2 2.79 110 2.29 90 1.14 45 3.18 125 2.03 80 2.29 90
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Conductor
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Size
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(AWG or kcmil)
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Dry Locations, Single Conductor Wet or Dry Locations
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Without Jacket
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Insulation
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With Jacket Single Conductor Multiconductor
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Insulation*
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Insulation Jacket Insulation Jacket mm mils mm mils mm mils mm mils mm mils mm mils
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1–2/0 2.79 110 2.29 90 1.14 45 3.18 125 2.03 80 2.29 90
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3/0–4/0 2.79 110 2.29 90 1.65 65 3.18 125 2.41 95 2.29 90
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213–500 3.05 120 2.29 90 1.65 65 3.56 140 2.79 110 2.29 90
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501–750 3.30 130 2.29 90 1.65 65 3.94 155 3.18 125 2.29 90
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751–1000 3.30 130 2.29 90 1.65 65 3.94 155 3.18 125 2.29 90
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1001–1250 3.56 140 2.92 115 1.65 65 4.32 170 3.56 140 2.92 115
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1251–1500 3.56 140 2.92 115 2.03 80 4.32 170 3.56 140 2.92 115
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1501–2000 3.56 140 2.92 115 2.03 80 4.32 170 3.94 155 3.56 140
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*Under a common overall covering such as a jacket, sheath, or armor.
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Conductor
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Size
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(AWG or kcmil)
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Conductor Size (AWG or kcmil)
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25,001–28,000 Volts 28,001–35,000 Volts
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100
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Percent
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Insulation
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Level
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133
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Percent
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Insulation
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Level
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173
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Percent
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Insulation
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Level
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100
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Percent
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Insulation
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Level
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133
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Percent
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Insulation
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Level
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173
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Percent
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Insulation
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100 Percent Insulation Level
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133 Percent Insulation Level
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173 Percent Insulation Level
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100 Percent Insulation Level
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133 Percent Insulation Level
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173 Percent Insulation
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Level mm mils mm mils mm mils mm mils mm mils mm mils
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1 7.11 280 8.76 345 11.30 445 — — — — — —
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@@ -169,11 +136,22 @@ Thickness of insulation for shielded solid dielectric insulated conductors rated
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##### 311.10(C)(1) 100 Percent Insulation Level.
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Cables shall be permitted to be applied where the system is provided with relay protection such that ground faults will be cleared as rapidly as possible but, in any case, within 1 minute. These cables are applicable to cable installations that are on grounded systems and shall be permitted to be used on other systems provided the above clearing requirements are met in completely de-energizing the faulted section.
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Cables shall be permitted to be applied
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where the system is provided with relay protection
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such that ground faults will be cleared as rapidly as possible but, in any case, within 1 minute.
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These cables are applicable to cable installations that are on grounded systems
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and shall be permitted to be used on other systems
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provided the above clearing requirements are met
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in completely de-energizing the faulted section.
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##### 311.10(C)(2) 133 Percent Insulation Level.
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Cables shall be permitted to be applied in situations where the clearing time requirements of the 100 percent level category cannot be met and the faulted section will be de-energized in a time not exceeding 1 hour. Cable shall be permitted to be used in 100 percent insulation level applications where the installation requires additional insulation.
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Cables shall be permitted to be applied
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in situations where the clearing time requirements
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of the 100 percent level category cannot be met
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and the faulted section will be de-energized in a time not exceeding 1 hour.
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Cable shall be permitted to be used in 100 percent insulation level applications
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where the installation requires additional insulation.
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##### 311.10(C)(3) 173 Percent Insulation Level.
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@@ -310,8 +288,7 @@ One or more of the methods in 311.16(B)(1) through (B)(4) shall be used for mark
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##### 311.16(B)(1) Surface Marking.
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Cables shall be durably marked on the surface. The AWG size or circular mil area shall be repeated at intervals not exceeding 610 mm
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(24 in.). All other markings shall be repeated at intervals not exceeding 1.0 m (40 in.).
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Cables shall be durably marked on the surface. The AWG size or circular mil area shall be repeated at intervals not exceeding 610 mm (24 in.). All other markings shall be repeated at intervals not exceeding 1.0 m (40 in.).
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##### 311.16(B)(2) Marker Tape.
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@@ -450,24 +427,21 @@ Under engineering supervision, conductor ampacities shall be permitted to be cal
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##### Equation 311.60(B)
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%% TODO %%
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T =
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T =
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ΔT =
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R =
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Y =
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R =
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$$
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I = \sqrt{ \frac{ T_{c} - ( T_{a} + \Delta T_{d} ) }{R_{dc} ( 1 + Y_{c}) R_{ca}} } \times 10^3~\text{amperes}
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$$
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where:
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conductor temperature (°C) ambient temperature (°C) dielectric loss temperature rise dc resistance of conductor at temperature, T component ac resistance resulting from skin effect and proximity effect effective thermal resistance between conductor and surrounding ambient c a d dc c c ca
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* $T_{c}$ conductor temperature (°C)
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* $T_{a}$ ambient temperature (°C)
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* $\Delta T_{d}$ dielectric loss temperature rise
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* $R_{dc}$ dc resistance of conductor at temperature, $T_{c}$
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* $Y_{c}$ component ac resistance resulting from skin effect and proximity effect
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* $R_{ca}$ effective thermal resistance between conductor and surrounding ambient
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> [!info] Informational Note:
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> The dielectric loss temperature rise (ΔT ) is negligible for single circuit extruded dielectric cables rated below 46 kilovolts.
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> The dielectric loss temperature rise ($\Delta T_{d}$)
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> is negligible for single circuit extruded dielectric cables rated below 46 kilovolts.
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#### 311.60(C) Tables.
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@@ -518,8 +492,7 @@ MV-105
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750 750 835 730 820
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1000 880 980 850 950
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Note: Refer to 311.60(E) for the basis of ampacities, 311.10(A) for conductor maximum operating temperature and application, and
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311.60(D)(4) for the ampacity correction factors where the ambient air temperature is other than 40°C (104°F).
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Note: Refer to 311.60(E) for the basis of ampacities, 311.10(A) for conductor maximum operating temperature and application, and 311.60(D)(4) for the ampacity correction factors where the ambient air temperature is other than 40°C (104°F).
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##### Table 311.60(C)(68) Ampacities of Insulated Single Aluminum Conductor Cables Triplexed in Air
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@@ -577,8 +550,7 @@ MV-105
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750 600 665 590 660
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1000 715 800 700 780
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Note: Refer to 311.60(E) for basis of ampacities, 311.10(A) for conductor maximum operating temperature and application, and
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311.60(D)(4) for the ampacity correction factors where the ambient air temperature is other than 40°C (104°F).
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Note: Refer to 311.60(E) for basis of ampacities, 311.10(A) for conductor maximum operating temperature and application, and 311.60(D)(4) for the ampacity correction factors where the ambient air temperature is other than 40°C (104°F).
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##### Table 311.60(C)(69) Ampacities of Insulated Single Copper Conductor Isolated in Air
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@@ -629,8 +601,7 @@ Type MV-105
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1750 1495 1665 1470 1640 1430 1595
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2000 1605 1790 1575 1755 1535 1710
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Note: Refer to 311.60(E) for the basis of ampacities, 311.10(A) for conductor maximum operating temperature and application, and
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311.60(D)(4) for the ampacity correction factors where the ambient air temperature is other than 40°C (104°F).
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Note: Refer to 311.60(E) for the basis of ampacities, 311.10(A) for conductor maximum operating temperature and application, and 311.60(D)(4) for the ampacity correction factors where the ambient air temperature is other than 40°C (104°F).
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##### Table 311.60(C)(70) Ampacities of Insulated Single Aluminum Conductor Isolated in Air
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@@ -739,8 +710,7 @@ MV-105
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750 615 685 670 745
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1000 705 790 770 860
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Note: Refer to 311.60(E) for the basis of ampacities, 311.10(A) for conductor maximum operating temperature and application, and
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311.60(D)(4) for the ampacity correction factors where the ambient air temperature is other than 40°C (104°F).
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Note: Refer to 311.60(E) for the basis of ampacities, 311.10(A) for conductor maximum operating temperature and application, and 311.60(D)(4) for the ampacity correction factors where the ambient air temperature is other than 40°C (104°F).
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##### Table 311.60(C)(72) Ampacities of an Insulated Three-Conductor Aluminum Cable Isolated in Air
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@@ -778,8 +748,7 @@ MV-105
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750 495 550 540 600
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1000 585 650 635 705
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Note: Refer to 311.60(E) for the basis of ampacities, 311.10(A) for conductor maximum operating temperature and application, and
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311.60(D)(4) for the ampacity correction factors where the ambient air temperature is other than 40°C (104°F).
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Note: Refer to 311.60(E) for the basis of ampacities, 311.10(A) for conductor maximum operating temperature and application, and 311.60(D)(4) for the ampacity correction factors where the ambient air temperature is other than 40°C (104°F).
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##### Table 311.60(C)(73) Ampacities of an Insulated Triplexed or Three Single-Conductor Copper Cables in Isolated Conduit in Air
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@@ -837,8 +806,7 @@ MV-105
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750 600 665 585 655
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1000 690 770 675 755
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Note: Refer to 311.60(E) for the basis of ampacities, 311.10(A) for conductor maximum operating temperature and application, and
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311.60(D)(4) for the ampacity correction factors where the ambient air temperature is other than 40°C (104°F).
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Note: Refer to 311.60(E) for the basis of ampacities, 311.10(A) for conductor maximum operating temperature and application, and 311.60(D)(4) for the ampacity correction factors where the ambient air temperature is other than 40°C (104°F).
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##### Table 311.60(C)(74) Ampacities of an Insulated Triplexed or Three Single-Conductor Aluminum Cables in Isolated Conduit in Air
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@@ -873,8 +841,7 @@ MV-105
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750 490 545 485 540
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1000 580 645 565 640
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Note: Refer to 311.60(E) for the basis of ampacities, 311.10(A) for conductor maximum operating temperature and application, and
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311.60(D)(4) for the ampacity correction factors where the ambient air temperature is other than 40°C (104°F).
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Note: Refer to 311.60(E) for the basis of ampacities, 311.10(A) for conductor maximum operating temperature and application, and 311.60(D)(4) for the ampacity correction factors where the ambient air temperature is other than 40°C (104°F).
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##### Table 311.60(C)(75) Ampacities of an Insulated Three-Conductor Copper Cable in Isolated Conduit in Air
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@@ -930,8 +897,7 @@ MV-105
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750 525 585 570 635
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1000 590 660 650 725
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Note: Refer to 311.60(E) for the basis of ampacities, 311.10(A) for conductor maximum operating temperature and application, and
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311.60(D)(4) for the ampacity correction factors where the ambient air temperature is other than 40°C (104°F).
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Note: Refer to 311.60(E) for the basis of ampacities, 311.10(A) for conductor maximum operating temperature and application, and 311.60(D)(4) for the ampacity correction factors where the ambient air temperature is other than 40°C (104°F).
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##### Table 311.60(C)(76) Ampacities of an Insulated Three-Conductor Aluminum Cable in Isolated Conduit in Air
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@@ -991,9 +957,8 @@ MV-90
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MV-105
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One Circuit \[See Figure 311.60(D)(3),
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One Circuit \[See Figure 311.60(D)(3), Detail 1.\]
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Detail 1.\]
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8 64 69 — —
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6 85 92 90 97
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4 110 120 115 125
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@@ -1009,9 +974,8 @@ Detail 1.\]
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750 585 630 565 610
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1000 670 720 640 690
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Three Circuits \[See Figure 311.60(D)(3),
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Three Circuits \[See Figure 311.60(D)(3), Detail 2.\]
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Detail 2.\]
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8 56 60 — —
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6 73 79 77 83
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4 95 100 99 105
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@@ -1027,9 +991,7 @@ Detail 2.\]
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750 460 495 440 475
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1000 525 565 495 535
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Six Circuits \[See Figure 311.60(D)(3),
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Detail 3.\]
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Six Circuits \[See Figure 311.60(D)(3), Detail 3.\]
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Conductor
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@@ -1085,9 +1047,7 @@ MV-90
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MV-105
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One Circuit \[See Figure 311.60(D)(3),
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|
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Detail 1.\]
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One Circuit \[See Figure 311.60(D)(3), Detail 1.\]
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8 50 54 — —
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6 66 71 70 75
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4 86 93 91 98
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@@ -1121,9 +1081,7 @@ MV-90
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MV-105
|
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|
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Three Circuits \[See Figure 311.60(D)(3),
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|
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Detail 2.\]
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Three Circuits \[See Figure 311.60(D)(3), Detail 2.\]
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8 44 47 — —
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6 57 61 60 65
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4 74 80 77 83
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@@ -1139,9 +1097,7 @@ Detail 2.\]
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750 370 395 355 385
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1000 425 460 405 440
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|
||||
Six Circuits \[See Figure 311.60(D)(3),
|
||||
|
||||
Detail 3.\]
|
||||
Six Circuits \[See Figure 311.60(D)(3), Detail 3.\]
|
||||
8 38 41 — —
|
||||
6 48 52 50 54
|
||||
4 62 67 64 69
|
||||
@@ -1197,9 +1153,7 @@ MV-90
|
||||
|
||||
MV-105
|
||||
|
||||
One Circuit \[See Figure 311.60(D)(3),
|
||||
|
||||
Detail 1.\]
|
||||
One Circuit \[See Figure 311.60(D)(3), Detail 1.\]
|
||||
8 59 64 — —
|
||||
6 78 84 88 95
|
||||
4 100 110 115 125
|
||||
@@ -1215,9 +1169,7 @@ Detail 1.\]
|
||||
750 530 570 545 585
|
||||
1000 600 645 615 660
|
||||
|
||||
Three Circuits \[See Figure 311.60(D)(3),
|
||||
|
||||
Detail 2.\]
|
||||
Three Circuits \[See Figure 311.60(D)(3), Detail 2.\]
|
||||
8 53 57 — —
|
||||
6 69 74 75 81
|
||||
4 89 96 97 105
|
||||
@@ -1233,31 +1185,11 @@ Detail 2.\]
|
||||
750 430 465 430 465
|
||||
1000 485 520 485 515
|
||||
|
||||
Six Circuits \[See Figure 311.60(D)(3),
|
||||
|
||||
Detail 3.\]
|
||||
Six Circuits \[See Figure 311.60(D)(3), Detail 3.\]
|
||||
8 46 50 — —
|
||||
6 60 65 63 68
|
||||
4 77 83 81 87
|
||||
2 98 105 105 110
|
||||
|
||||
Conductor
|
||||
|
||||
Size
|
||||
(AWG or kcmil)
|
||||
|
||||
Temperature Rating of Conductor
|
||||
2001–5000 Volts Ampacity 5001–35,000 Volts Ampacity
|
||||
90°C (194°F) Type MV90105°C
|
||||
(221°F) Type
|
||||
|
||||
MV-105
|
||||
90°C (194°F) Type
|
||||
|
||||
MV-90
|
||||
105°C (221°F) Type
|
||||
|
||||
MV-105
|
||||
1 110 120 115 125
|
||||
1/0 125 135 130 145
|
||||
2/0 145 155 150 160
|
||||
@@ -1309,28 +1241,8 @@ Detail 1.\]
|
||||
750 425 460 440 475
|
||||
1000 495 535 510 545
|
||||
|
||||
Three Circuits \[See Figure 311.60(D)(3),
|
||||
|
||||
Detail 2.\]
|
||||
Three Circuits \[See Figure 311.60(D)(3), Detail 2.\]
|
||||
8 41 44 — —
|
||||
|
||||
Conductor
|
||||
|
||||
Size
|
||||
(AWG or kcmil)
|
||||
|
||||
Temperature Rating of Conductor
|
||||
2001–5000 Volts Ampacity 5001–35,000 Volts Ampacity
|
||||
90°C (194°F) Type MV90105°C
|
||||
(221°F) Type
|
||||
|
||||
MV-105
|
||||
90°C (194°F) Type
|
||||
|
||||
MV-90
|
||||
105°C (221°F) Type
|
||||
|
||||
MV-105
|
||||
6 54 58 59 64
|
||||
4 70 75 75 81
|
||||
2 90 97 100 105
|
||||
@@ -1385,8 +1297,7 @@ MV-90
|
||||
|
||||
MV-105
|
||||
|
||||
One Circuit, Three Conductors \[See Figure
|
||||
311.60(D)(3), Detail 9.\]
|
||||
One Circuit, Three Conductors \[See Figure 311.60(D)(3), Detail 9.\]
|
||||
|
||||
Conductor
|
||||
|
||||
@@ -1420,8 +1331,7 @@ MV-105
|
||||
750 845 910 805 865
|
||||
1000 980 1055 930 1005
|
||||
|
||||
Two Circuits, Six Conductors \[See Figure
|
||||
311.60(D)(3), Detail 10.\]
|
||||
Two Circuits, Six Conductors \[See Figure 311.60(D)(3), Detail 10.\]
|
||||
8 100 110 — —
|
||||
6 130 140 120 130
|
||||
4 165 180 160 170
|
||||
@@ -1477,8 +1387,7 @@ MV-90
|
||||
|
||||
MV-105
|
||||
|
||||
One Circuit, Three Conductors \[See Figure
|
||||
311.60(D)(3), Detail 9.\]
|
||||
One Circuit, Three Conductors \[See Figure 311.60(D)(3), Detail 9.\]
|
||||
8 85 90 — —
|
||||
6 110 115 100 110
|
||||
4 140 150 130 140
|
||||
@@ -1494,8 +1403,7 @@ One Circuit, Three Conductors \[See Figure
|
||||
750 665 720 635 680
|
||||
1000 780 840 740 795
|
||||
|
||||
Two Circuits, Six Conductors \[See Figure
|
||||
311.60(D)(3), Detail 10.\]
|
||||
Two Circuits, Six Conductors \[See Figure 311.60(D)(3), Detail 10.\]
|
||||
8 80 85 — —
|
||||
6 100 110 95 100
|
||||
4 130 140 125 130
|
||||
@@ -1555,9 +1463,7 @@ MV-90
|
||||
|
||||
MV-105
|
||||
|
||||
One Circuit \[See Figure 311.60(D)(3),
|
||||
|
||||
Detail 5.\]
|
||||
One Circuit \[See Figure 311.60(D)(3), Detail 5.\]
|
||||
8 85 89 — —
|
||||
6 105 115 115 120
|
||||
4 135 150 145 155
|
||||
@@ -1573,9 +1479,7 @@ Detail 5.\]
|
||||
750 650 700 665 720
|
||||
1000 730 785 750 810
|
||||
|
||||
Two Circuits \[See Figure 311.60(D)(3),
|
||||
|
||||
Detail 6.\]
|
||||
Two Circuits \[See Figure 311.60(D)(3), Detail 6.\]
|
||||
8 80 84 — —
|
||||
6 100 105 105 115
|
||||
4 130 140 135 145
|
||||
@@ -1633,9 +1537,7 @@ MV-90
|
||||
|
||||
MV-105
|
||||
|
||||
One Circuit \[See Figure 311.60(D)(3),
|
||||
|
||||
Detail 5.\]
|
||||
One Circuit \[See Figure 311.60(D)(3), Detail 5.\]
|
||||
8 65 70 — —
|
||||
6 80 88 90 95
|
||||
4 105 115 115 125
|
||||
@@ -1651,9 +1553,7 @@ Detail 5.\]
|
||||
750 520 560 540 580
|
||||
1000 600 650 620 665
|
||||
|
||||
Two Circuits \[See Figure 311.60(D)(3),
|
||||
|
||||
Detail 6.\]
|
||||
Two Circuits \[See Figure 311.60(D)(3), Detail 6.\]
|
||||
8 60 66 — —
|
||||
6 75 83 80 95
|
||||
4 100 110 105 115
|
||||
@@ -1708,8 +1608,7 @@ MV-90
|
||||
|
||||
MV-105
|
||||
|
||||
One Circuit, Three Conductors \[See Figure
|
||||
311.60(D)(3), Detail 7.\]
|
||||
One Circuit, Three Conductors \[See Figure 311.60(D)(3), Detail 7.\]
|
||||
8 90 95 — —
|
||||
6 120 130 115 120
|
||||
4 150 165 150 160
|
||||
@@ -1725,8 +1624,7 @@ One Circuit, Three Conductors \[See Figure
|
||||
750 725 780 685 740
|
||||
1000 825 885 770 830
|
||||
|
||||
Two Circuits, Six Conductors \[See Figure
|
||||
311.60(D)(3), Detail 8.\]
|
||||
Two Circuits, Six Conductors \[See Figure 311.60(D)(3), Detail 8.\]
|
||||
8 85 90 — —
|
||||
6 110 115 105 115
|
||||
4 140 150 140 150
|
||||
@@ -1840,82 +1738,55 @@ Where the burial depth of direct burial or electrical duct bank circuits is modi
|
||||
|
||||
##### 311.60(D)(3) Electrical Ducts Entering Equipment Enclosures.
|
||||
|
||||
At locations where electrical ducts enter equipment enclosures from underground, spacing between such ducts, as shown in Figure
|
||||
311.60(D)(3), shall be permitted to be reduced without requiring the ampacity of conductors therein to be reduced.
|
||||
At locations where electrical ducts enter equipment enclosures from underground, spacing between such ducts, as shown in Figure 311.60(D)(3), shall be permitted to be reduced without requiring the ampacity of conductors therein to be reduced.
|
||||
|
||||
Figure 311.60(D)(3) Cable Installation Dimensions for Use with Table 311.60(C)(77) Through Table
|
||||
311.60(C)(86).
|
||||
|
||||
##### 311.60(D)(4) Ambient Temperature Correction.
|
||||
|
||||
Ampacities for ambient temperatures other than those specified in the ampacity tables shall be corrected in accordance with Table
|
||||
311.60(D)(4) or shall be permitted to be calculated using the following equation:
|
||||
|
||||
###### Equation 311.60(D)(4)
|
||||
###### Figure 311.60(D)(3) Cable Installation Dimensions for Use with Table 311.60(C)(77) Through Table 311.60(C)(86).
|
||||
|
||||
%% TODO %%
|
||||
|
||||
I' =
|
||||
##### 311.60(D)(4) Ambient Temperature Correction.
|
||||
|
||||
I =
|
||||
Ampacities for ambient temperatures other than those specified in the ampacity tables shall be corrected in accordance with Table 311.60(D)(4) or shall be permitted to be calculated using the following equation:
|
||||
|
||||
T =
|
||||
###### Equation 311.60(D)(4)
|
||||
|
||||
T ' =
|
||||
$$
|
||||
I^{\prime} = I \sqrt{\frac{ T_{c} -T_{a}^{\prime} }{ T_{c} - T_a }}
|
||||
$$
|
||||
|
||||
T = where: ampacity corrected for ambient temperature ampacity shown in the table for T and T temperature rating of conductor (°C) new ambient temperature (°C) ambient temperature used in the table (°C)
|
||||
where:
|
||||
|
||||
* $I\prime$ = ampacity corrected for ambient temperature
|
||||
* $I$ = ampacity shown in the tables
|
||||
* $T_{c}$ = temperature rating of conductor (°C)
|
||||
* $T_{a}^{\prime}$ = new ambient temperature (°C)
|
||||
* $T_a$ = ambient temperature used in the table (°C)
|
||||
|
||||
###### Table 311.60(D)(4) Ambient Temperature Correction Factors
|
||||
|
||||
For ambient temperatures other than 40°C (104°F), multiply the allowable ampacities specified in the ampacity tables by the appropriate factor shown below.
|
||||
|
||||
Ambient
|
||||
|
||||
Temperature
|
||||
(°C)
|
||||
|
||||
Temperature Rating of Conductor Ambient
|
||||
|
||||
Temperature
|
||||
(°F)
|
||||
90°C 105°C
|
||||
10 or less 1.26 1.21 50 or less
|
||||
11–15 1.22 1.18 51–59
|
||||
16–20 1.18 1.14 60–68
|
||||
21–25 1.14 1.11 69–77
|
||||
26–30 1.10 1.07 78–86
|
||||
31–35 1.05 1.04 87–95
|
||||
36–40 1.00 1.00 96–104
|
||||
41–45 0.95 0.96 105–113
|
||||
46–50 0.89 0.92 114–122
|
||||
51–55 0.84 0.88 123–131
|
||||
56–60 0.77 0.83 132–140
|
||||
61–65 0.71 0.78 141–149
|
||||
66–70 0.63 0.73 150–158
|
||||
71–75 0.55 0.68 159–167
|
||||
76–80 0.45 0.62 168–176
|
||||
81–85 0.32 0.55 177–185
|
||||
86–90 — 0.48 186–194
|
||||
91–95 — 0.39 195–203
|
||||
96–100 — 0.28 204–212 c a c a a
|
||||
|
||||
Ampacities for conductors and cables in underground electrical ducts and direct buried in earth shall be as specified in Table 311.60(C)
|
||||
|
||||
* (77) through Table 311.60(C)(86). Ampacities shall be based on the following:
|
||||
|
||||
* (1) Ambient earth temperature of 20°C (68°F)
|
||||
|
||||
* (2) Arrangement in accordance with Figure 311.60(D)(3)
|
||||
|
||||
* (3) 100 percent load factor
|
||||
|
||||
* (4) Thermal resistance (Rho) of 90
|
||||
|
||||
* (5) Conductor temperatures 90°C (194°F) and 105°C (221°F)
|
||||
|
||||
* (6) Minimum burial depths to the top electrical ducts or cables shall be in accordance with 300.50.
|
||||
|
||||
* (7) Maximum depth to the top of electrical duct banks shall be 750 mm (30 in.), and maximum depth to the top of direct-buried cables shall be 900 mm (36 in.).
|
||||
| Ambient Temperature °C (°F) | 90°C | 105°C |
|
||||
| --------------------------- | ---- | ----- |
|
||||
| 10 or less (50 or less) | 1.26 | 1.21 |
|
||||
| 11–15 (51–59) | 1.22 | 1.18 |
|
||||
| 16–20 (60–68) | 1.18 | 1.14 |
|
||||
| 21–25 (69–77) | 1.14 | 1.11 |
|
||||
| 26–30 (78–86) | 1.10 | 1.07 |
|
||||
| 31–35 (87–95) | 1.05 | 1.04 |
|
||||
| 36–40 (96–104) | 1.00 | 1.00 |
|
||||
| 41–45 (105–113) | 0.95 | 0.96 |
|
||||
| 46–50 (114–122) | 0.89 | 0.92 |
|
||||
| 51–55 (123–131) | 0.84 | 0.88 |
|
||||
| 56–60 (132–140) | 0.77 | 0.83 |
|
||||
| 61–65 (141–149) | 0.71 | 0.78 |
|
||||
| 66–70 (150–158) | 0.63 | 0.73 |
|
||||
| 71–75 (159–167) | 0.55 | 0.68 |
|
||||
| 76–80 (168–176) | 0.45 | 0.62 |
|
||||
| 81–85 (177–185) | 0.32 | 0.55 |
|
||||
| 86–90 (186–194) | — | 0.48 |
|
||||
| 91–95 (195–203) | — | 0.39 |
|
||||
| 96–100 (204–212) | — | 0.28 |
|
||||
|
||||
#### 311.60(E) Ampacity in Air.
|
||||
|
||||
@@ -1930,3 +1801,23 @@ Ampacities for conductors and cables in air shall be as specified in Table 311.6
|
||||
|
||||
#### 311.60(F) Ampacity in Underground Electrical Ducts and Direct Buried in Earth.
|
||||
|
||||
Ampacities for conductors and cables
|
||||
in underground electrical ducts and direct buried in earth
|
||||
shall be as specified in Table 311.60(C)(77) through Table 311.60(C)(86).
|
||||
Ampacities shall be based on the following:
|
||||
|
||||
* (1) Ambient earth temperature of 20°C (68°F)
|
||||
|
||||
* (2) Arrangement in accordance with Figure 311.60(D)(3)
|
||||
|
||||
* (3) 100 percent load factor
|
||||
|
||||
* (4) Thermal resistance (Rho) of 90
|
||||
|
||||
* (5) Conductor temperatures 90°C (194°F) and 105°C (221°F)
|
||||
|
||||
* (6) Minimum burial depths to the top electrical ducts or cables
|
||||
shall be in accordance with 300.50.
|
||||
|
||||
* (7) Maximum depth to the top of electrical duct banks shall be 750 mm (30 in.),
|
||||
and maximum depth to the top of direct-buried cables shall be 900 mm (36 in.).
|
||||
|
||||
Reference in New Issue
Block a user