Original
General Order
95
Section
III
Requirements for All Lines
Table 2
Basic Minimum Allowable Clearance of Wires from Other Wires at Crossings
and at Supports
(Letter references Denote Modifications of Minimum Clearances Referred to
in Notes Following this Table)
All Clearances Are in Inches
|
Case No. |
Nature of Clearance and Class of Voltage of wire, cable or conductor concerned |
Other Wire, cable or conductor concerned |
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|
A |
B Trolley contact conductors0-750 volts |
C Communication conductors (including open wire, cables and service drops) Supply conductor (including supply cables) |
D |
Supply conductor (including supply cables) |
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|
E |
F 7,500 - 20,000 volts |
G 20,000 - 35,000 volts |
H |
I |
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Clearance between wires, cables, and conductors not supported on the same poles, vertically at crossings in spans, and radially where collinear or approaching crossing |
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|
1 |
Span wires, guys and messengers (b) |
18 (c) |
24 (e) |
24 (e) |
36 (f) |
36 |
72 |
72 |
72(g) |
|
|
2 |
Trolley contact conductors 0-750 volts |
------------- |
48 (d) |
48 |
72 |
96 |
96 |
96(g) |
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|
3 |
Communication conductors |
24 (e) |
48 (d) |
24 |
48 (i) |
48 (dd) |
72 |
96 |
96 |
96(g) |
|
4 |
Supply conductors, service drops and trolley feeders 0-750 volts |
24 (e) |
48 (i) |
24 |
48 |
48 |
96 |
96 |
96(g) |
|
|
5 |
Supply conductors, 750-7500 volts |
36 (f) |
48 |
48 (dd) |
48 |
48 (h) |
72 |
96 |
96 |
96(g) |
|
6 |
Supply conductors 7500-20,000 volts |
36 |
72 |
72 |
48 |
72 |
72 |
96 |
96 |
96(g) |
|
7 |
Supply conductors, more than 20,000 volts |
72 |
96 |
96 |
96 |
96 |
96 |
96 |
96 |
96(g) |
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Vertical separation between conductors and / or cables on separate crossarms or other supports at different levels (excepting on related line and buck arms on the same pole) |
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|
8 |
Communication conductors and service drops |
------------- |
------------- |
12 (j) |
48 (k) |
72(m) |
72 |
72 |
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|
9 |
Supply Conductors, service drops and trolley feeders 0-750 volts |
------------- |
------------- |
72(m) |
72 |
72 |
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|
10 |
Supply conductors, 750-7500 volts |
------------- |
------------- |
48 (k) |
48(q) |
48(q) |
60(q) |
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|
11 |
Supply conductors 7500-20,000 volts |
------------- |
------------- |
72 (m, n) |
48(q) |
48(q) |
60(q) |
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|
12 |
Supply conductors 20,000-68,000 volts |
------------- |
------------- |
72 (m) |
72 (m) |
60(q) |
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|
13 |
Supply conductors, more than 68,000 volts |
------------- |
------------- |
72 |
72 |
60 (q) |
60(q) |
60(q) |
60(q) |
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Vertical arms above or below conductors on related line arms and buck arms. |
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|
14 |
------------- |
------------- |
6 |
12 (u) |
18 (u) |
18 (u) |
24 |
36 |
48(g) |
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Horizontal separation of conductors on same crossarm |
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|
15 |
Pin spacings of longitudinal conductors, vertical conductors and service drops |
------------- |
------------- |
3(x) |
11 ½ (x) |
17 ½ (x) |
24 (x) |
36 |
48(g) |
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|
Radial separation of conductors on same crossarm, pole or structure Incidental pole wiring |
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16 |
Conductors, tap or lead wires of different circuits (v, y, z) |
------------- |
------------- |
3 (x) |
11 ½ (x) |
17 ½ (x) |
24 (x) |
36 |
48(g) |
|
|
17 |
------------- |
------------- |
3 |
3 |
6 |
6 |
12 |
18 |
24 |
|
|
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Radial separation between guys and conductors |
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18 |
Guys passing conductors supported on other poles, and guys approximately parallel to conductors supported on the same poles |
------------- |
------------- |
9 (bb) |
12 |
18 |
18 |
30 |
36 |
36 |
|
19 |
Guys and spans wires passing conductors supported on the same poles |
--------------- |
3 |
9 |
6 |
9 |
12 |
18 |
24 |
|
(a) The clearances in Column D are also applicable to
supply cables of any voltage under certain conditions 57.4
(b) Clearances for guys and span wires apply vertically
at crossings; see Case 18 for radial clearances from conductors.
1. Supply guys and span wires from conductors 56.4-C
2. Supply guys and span wires from guys and span wires 56.4-D1
3. Communication guys and span wires from conductors 86.4-C
4. Communication guys and span wires from guys and span wires 86.4-D1
(c) Not applicable between messengers or span wires of
the same system.
1. Supply messengers 57.4-E
2. Trolley span wires77.4-D
3. Communication messengers 87.4-G
(d) Protection required on guys, span wires, messengers,
and cables where within trolley throw
1. Supply Guys and Span wires 56.4-B2
2. Supply Messengers and Cables 57.4-B2
3. Communication guys and span wires 86.4-B2
4. Communication messengers 87.4-B2
(e) Not applicable to certain conductors supported on trolley
span wires.
1. Trolley contact and feeder conductors 74.4-G
2. Trolley feeder conductors78.1
3. Trolley system communication conductors 78.2
4. Foreign conductors 78.3
(f) Increased clearance required over trolley contact conductors
of 750-7500 volts 74.4-G2
(g) Shall be increased for conductors of more than 68,000
volts.
1. Conductors not supported on the same poles 54.4-C7a
2. Conductors supported on the same crossarm, pole or structure. 54.4-C7b
(h) May be reduced for certain conductors of Class T circuits
of the same system 74.4-C
(i) May be reduced for service drops under special conditions.
1. Supply service drops and communication line conductors 54.8-C1a
2. Supply service drops and communication service drops 54.8-C4
3. Communication service drops and supply line conductors 84.8-D1a
4. Communication service drops and supply service drops 84.8-D4
(j) May be reduced or shall be increased for certain communication
conductors or cables.
1. Open wire conductors, attached to poles, within 3
feet of topmost conductor 84.4-C1c
2. Line conductors of police or fire-alarm circuits and service drops
from other communication circuits. 84.8-D1b
3. Cables and messengers attached to poles 87.4-C3
(k) Special clearances for 0-750 volt conductors in rack
configuration and messengers and cables attached to poles.
1. Supply conductors of 0-750 volts in rack configuration 54.9
2. Supply cables and messengers attached to poles 57.4-F
3. Communication cables and messengers attached to poles 87.4-C3
4. On Jointly used poles 92.1
(l) May be reduced for service drops, and police or fire-alarm
conductors, under special conditions.
1. Supply service drops and communication line conductors 54.8-C1b
2. Supply service drops on clearance arms 54.8-C2
3. Supply service drops on pole-top extensions 54.8-C3
4. Supply service drops and communication service drops 54.8-C4
5. Communication service drops and police, fire-alarm or supply line conductors 84.8-D1b
6. Communication service drops on clearance arms 84.8-D2
7. Communication service drops on pole-top extensions 84.8-D3
8. Communication service drops and supply service drops 84.8-D4
9. Police or fire-alarm conductors 92.2
(m) May be reduced for lead wires
1. Supply lead wires above supply conductors 54.4-C6
2. Supply drip loops above communication conductors 92.1-F3
(n) May be reduced for supply conductors and private communication
conductors of the same ownership 89.2-B
(o) May be reduced or increased for triangular or vertical
configuration or for pole-top construction.
1. Triangular or vertical configuration on crossarms 54.4-C1c
2. Dead-ended on pole in vertical configuration 54.4-C4
3. Conductors of 0-7500 volts in triangular configuration at top of pole 54.4-D8a
4. Conductors of more than 7500 volts at top of pole 54.4-D8b
(p) May be reduced for supply service drops of 0-750 volts
54.8-C6
(q) Shall be increased between circuits where conductors
of more than 7500 volts are at pole top. 54.4-D8b
(r) May be reduced under special conditions
1. Supply conductors of 750-7500 volts 54.4-C1a
2. Supply conductors of 7500-20,000 volts 54.4-C1b
(s) Does not apply where conductors do not cross.
1. Supply conductors of different phase polarity 54.4-C2a
2. Communication conductors 84.4-C1a
(t) Shall not be applied consecutively both above and below
the same supply conductors 54.4-C2a
(u) Shall be increased where conductors of different classifications
are supported on the same crossarms.
1. Supply conductors of 0-750 volts and conductors of 7500-20,000 volts 32.4-A2
2. Supply conductors of 0-750 volts and conductors of 750-7500 volts 32.4-A3
(v) Not applicable to certain kinds of conductors.
1. Supply conductors of same phase or polarity 54.4-C3c
2. Insulated supply conductors in multiple-conductor cables 57.4-C
3. Communication insulated conductors or multiple-conductor cables 87.4-C1
(w) Shall apply radially to conductors on brackets attached
to crossarms.
1. Supply conductors 54.4-C3b
2. Communication conductors 84.4-C1b
(x) Shall be increased between conductors of different
classifications supported on the same crossarm.
1. Supply conductors of different voltage classification 32.4-A
2. Supply circuits of 0-750 volts and communication circuits 32.4-B
3. Supply circuits and private communication circuits. 89.2-A
(y) Special clearances for unprotected supply conductors
from one level to another level
(z) Not applicable to the following:
1. Clearances between conductors at different levels specified in Cases 8 to 13 inclusive.
2. Supply lateral conductors, suitably protected 54.6-C
3. Supply vertical runs, suitably protected 54.6-D
4. Supply risers, suitably protected 54.6-E
5. Communication Conductors 87.4-C1
(aa) Not applicable between cables and their supporting
messengers.
(bb) May be reduced for communication guys and communication
conductors supported on the same poles 86.4-C3
(cc) Clearance required between guys.
1. Supply guys, crossing 56.4-D2
2. Supply guys, approximately parallel 56.4-D3
3. Communication guys, crossing 86.4-D2
4. Communication guys, approximately parallel 86.4-D3
(dd) Shall be increased where within 6 feet of a pole
103.5