Original Version
Table 1
Basic Minimum Allowable Vertical Clearance of Wire Above Railroads, Thoroughfares and Ground; Also clearances from Poles, Buildings, Structures or Other Objects(nn)
(Letter References Denote Modifications of Minimum Clearances as Referred to in Note Following this Table)
|
Case No |
Nature of Clearance |
Wire or Conductor Concerned |
||||||
|
A |
B |
C |
D |
E |
F Supply Conductors and supply cables 22.5 – 300 kV |
G (mm)Supply Conductors and supply cables more 300 - 550 kV |
||
|
1 |
Crossing above tracks of railroads which transport or propose to transport freight cars (max height 15 ft 1in) where not operated by overhead contact wires (a) (b) (c) (d) |
25 ft |
25 ft |
22 ft |
25 ft |
28 ft |
34 ft |
34 ft |
|
2 |
Crossing or paralleling above tracks of railroads operated by overhead trolleys (b) (c) (d) |
26 ft (e) |
26 ft (e) (f) (g) |
19 ft (h) (i) |
27 ft (e) (g) |
30 ft (g) |
34 ft (g) |
34 ft (g) (kk) |
|
3 |
Crossing or along thoroughfares in Urban districts or crossings thoroughfares in rural districts (c) (d) |
18 ft (j) (k) (ii) |
18 ft (j) (l) (m) (ii) |
19 ft (hh) |
20 ft (ii) |
25 ft (n) (o) (ii) |
30 ft (o) (ii) |
30 ft (o) (ii) (kk) |
|
4 |
Above ground along thoroughfares in rural districts or across other areas capable of being transversed by vehicles or agricultural equipment. |
15 ft (k) |
15 ft (m) (n) (p) |
19 ft |
16 ft |
25 ft (n) (o) |
30 ft (o) (p) |
30 ft. (o) (kk) |
|
5 |
Vertical ground in areas accessible to pedestrians only. |
7 ft |
10 ft (m) (q) |
19 ft |
12 ft |
17 ft |
25 ft (o) |
25 ft. (o) (kk) |
|
6 |
Vertical clearance above buildings and bridges (or other structures which do not ordinarily support conductors and on which men can walk) whether attached or unattached. |
8 ft (r) |
8 ft (r) |
8 ft |
8 ft |
12 ft |
12 ft |
20 ft (ll) |
|
7 |
Horizontal clearance of conductor from buildings (except generating and substations), bridges or other structures (upon which men may work) where such conductor is not attached thereto. (a) (t) |
-------------- |
3 ft (u) |
3 ft |
3 ft (u) (v) |
6 ft (v) |
6 ft (v) |
15 ft (v) |
|
8 |
Distance of conductor from center line of pole, wheter attached or unattached (w) (x) (y) |
-------------- |
15 in (a) (aa) |
15 in (aa) (bb) (cc) |
15 in (aa) (o) (dd) |
15 or 18 in (o) (dd) (ee) (jj) |
18 in (dd) (ee) (jj) |
Not Applicable |
|
9 |
Distance of conductor from surface of pole, crossarm or other overhead line structure upon which it is supported, providing it complies with Case 8 above (x) (ee) |
-------------- |
3 in (aa) (ff) |
3 in (aa) (cc) (gg) |
3 in (aa) (dd) (gg) |
3 in (dd) (gg) |
¼ pin spacing shown in Table 2 Case 15 (dd) |
½ pin spacing shown in Table 2 Case 15 (dd) |
|
10 |
Radial centerline clearance of conductor or cable (unattached) from non-climbable street lighting or traffic signal poles or standards, including mastarms, brackets and lighting fixtures. |
------------- |
1 ft (oo) (u) (rr) (ss) |
15 in. (bb) (cc |
3 ft (oo) |
6 ft (pp) |
10 ft (qq) |
10 ft (ll) |
(a) Shall not be reduced more than 5% because
of temperature or loading
37
1. Supply Lines 54.4-B1
2. Communication Lines 84.4-B1
(b) Shall be increased for supply conductors
on Suspension insulators, under certain conditions
37
(c) Special clearances are provided for traffic
signal equipment
58.1-C
(d) Special clearances are provided for street
lighting equipment
58.2-B
(e) Based on trolley pole throw of 26 feet.
May be reduced where suitably protected.
1. Supply Guys 56.4-B2
2. Supply cables and messengers 57.4-B2
3. Communication Guys 86.4-B2
4. Communication cables and messengers 87.4-B2
(f) May be reduced depending on height of trolley
contact conductors.
1. Supply Service Drop 54.8-C5
2. Communication service drops 84.8-D5
(g) May be reduced and shall be increased depending
on trolley throw
1. Supply conductors (except service drops) 54.4-B2
2. Communication conductors (except service drops) 84.4-B2
(h) Shall be increase where freight cars are
transported.
1. Trolley contact and feeder conductors 74.4-B1
2. Trolley span wires 77.4-A
(i) May be reduced for trolley contact and span
wires in subways, tunnels and under bridges
1. Trolley contact conductors 74.4-E
2. Trolley span wires 77.4-A
(j) May be reduced at crossings over private
thoroughfares and entrances to private property and over private property.
1. Supply Service drops 54.8-B2
2. Supply Guys 56.4-A
3. Communication service drops 84.8-C2
4. Communication guys 86.4-A
(k) May be reduced along thoroughfares where
not normally accessible to vehicles.
1. Supply Guys 56.4-A1
2. Communication Guys 86.4-A1
(l) May be reduced where within 12 feet of curb
line of public thoroughfares
1. Supply Service drops 54.8-B1
2. Communication service drops 84.8-C1
(m) May be reduced for railways signal cables
under special conditions
84.4-A4
(n) May be reduced in rural districts
1. Supply conductors, 750-20,000 volts, crossing roads or driveways 54.4-A2a
2. Supply conductors, 750-20,000 volts, above agricultural areas and along roads 54.4-A2b
3. Communication conductors along roads 84.4-A2
(o) May be reduced for transformer, regulator
or capacitor leads.
1. Transformer Leads 58.3-B
2. Regulator or Capacitor Leads 58.4-B
(p) May be reduced across arid or mountainous
areas
1. Supply Conductors of more than 22, 500 Volts 54.4-A1
2. Communication conductors 84.4-A1
(q) Shall be increased or may be reduced under
special conditions.
1. Increased for supply service drops on industrial or commercial premises 54.8-B3a
2. Supply service drops on residential premises 54.8-B3b
3. Communication conductors 84.4-A3
4. Increased for Communication service drops on industrial or commercial premises 84.8-C3a
5. Communication service drops on residential premises 84.8-C3b
(r) May be reduced above roofs of buildings
under special conditions
1. Supply overhead guys 56.4-G
2. Supply service drops 54.8-B4
3. Communication overhead guys 86.4-F
4. Communication conductors and cables 84.4-E
5. Communication service drops 84.8-C4
(s) Also applies at fire escapes, etc.
1. Supply Conductors 54.4-H1
2. Supply service drops on industrial or commercial premises 54.8-B4a
3. Supply service drops on residential premises 54.8-B4b
4. Communication Conductor 84.4-E
(t) Special Clearances where attached to buildings,
bridges or other structures
1. Supply conductors of 750-22,500 volts 54.4-H2
2. Trolley Contact Conductors 74.4-E
3. Communication Conductors 84.4- F
(u) Reduced clearances permitted under special
conditions
1. Supply service drops on industrial or commercial premises 54.8-B4a
2. Supply cables, grounded 57.4-G
3. Communication cables beside buildings, etc. 84.4-E
4. Communication conductors under bridges, etc. 84.4-F
5. Communication service drops. 84.8-C4
6. Communication cables passing on non-climable streetlight poles, etc. 84.4-D4a
(v) May be reduced under special conditions.
1. Supply conductors of 750-7500 volts 54.4-H1
2. Supply transformer lead and bus wires where guarded 58.3-B2
(w) May be reduced at angles in lines and transportation
points
1. Supply conductors 54.4-D1
2. Communication Conductors 84.4-D5
(x) May be reduced for suitably protected lateral
or vertical runs.
1. Supply bond wires 53.4
2. Supply ground wires 54.6-B
3. Supply lateral conductors 54.6-C
4. Supply vertical pins 54.6-D
5. Supply risers 54.6-E
6. Communication Ground Wires 84.6-B
7. Communication lateral conductors 84.6-C
8. Communication vertical runs 84.6-D
9. Communication risers 84.6-E
(y) Increased clearances for certain conductors
1. Unattached conductors on colinear lines and crossing lines 32.3
2. Unattached supply conductors 54.4D3
3. Supply Service drops on clearance crossarms 54.8-C2
4. Supply Service drops on pole top extensions 54.8-C3
5. Unattached Supply service drops 54.8-D
6. Communication lines, collinear, conflicting or crossing 84.4-D3
7. Communication conductors passing supply poles and unattached thereto 84.4-D4
8. Communication service drops on clearance crossarms 84.8-D2
9. Communication service drops on pole top extensions 84.8-D3
10. Unattached Communication service drops 84.8-E
(z) Special provisions for police and fire alarm
conductors require increased clearances
92.2
(aa) May be reduced under special provisions.
1. Supply conductors of 0-750 volts in rack configuration 54.4-D5
2. Supply service drops from racks 54.8-F
3. Supply cables and messengers attached to poles 57.4-F
4. Communication conductors on communication poles 84.4-D
5. Communication conductors on crossarms 84.4-D1
6. Communication conductors attached to poles 84.4-D2
7. Communication service drops attached to poles 84.8-B
8. Communication cables and messengers 87.4-D
9. Supply or communication cables and messengers on jointly used poles 92.1-B
10. Communication service drops on pole top extensions 92.1-C
(bb) May be reduced for Class T conductors of
not more than 750 volts and of the same potential and polarity
74.4-D
(cc) Not applicable to trolley span wires 77.4-E
(dd) Special clearances for pole-top and dead-end
construction
1. Conductors dead-ended in vertical configuration on poles 54.4-C4
2. Conductors dead-ended in horizontal configuration 54.4-D7
3. Conductors in pole-top construction 54.4-D8
(ee) Clearance requirements for certain voltage
classifications
54.4-D2
(ff) Not applicable to communication conductors
84.4-D
(gg) Clearance from crossarms may be reduced
for certain conductors
1. Suitably insulated leads to protected runs 54.4-E
2. Leads of 0-5000 volts to equipment 54.4-E
3. Leads of 0-5000 volts to cutouts or switches 58.5-C
(hh) Reduced clearance permitted from temporary
fixtures and lighting circuits 0-300 volts
78.3A(1)
(ii) Special Clearances Required Above Public
and Private Swimming Pools:
1. Supply line conductors 54.4–A4
2. Supply service drops 54.8–B5
3. Communication line conductors 84.4–A5
4. Communication service drops 84.8–C5
5. Supply guys, span wires 56.4–A3
6. Communication guys 86.4–A3
(jj)
May be decreased in partial underground distribution
54.4-D2
(kk)
Shall be increased by 0.025
ft. per kV in excess of 300 kV.
(ll)
Shall
be increased by 0.04 ft per kV in excess of 300 kV.
(mm) proposed clearances to be
submitted tot the CPUC prior to construction for circuits in excess of 550
kV.
(nn) Voltage shown in the table
shall mean line – to – ground voltage for direct current (DC) systems.
(oo) May be reduced for grounded or multi-conductor cables.
1. Grounded cables 57.4-H
2. Multi-Conductor cables 54.10-B6
(pp) May be reduced to 4 feet for voltages below 7,500 volts 54.4-D3
(qq) May be reduced to 6 feet for voltages below 75 kV
(rr) May be reduced for supply service drops 54.8-D1
(ss) May be reduced to communication service drops 84.4-E1
Strikeout and Underline Version
Table 1
Basic Minimum Allowable
Vertical Clearance of Wire Above Railroads, Thoroughfares ,and Ground or
Water Surface; Also clearances from Poles, Buildings, Structures or Other
Objects(nn)
(Letter References Denote Modifications of Minimum Clearances as Referred to in Note Following this Table)
|
Case No |
Nature of Clearance |
Wire or Conductor Concerned |
||||||
|
A |
B |
C |
D |
E |
F Supply Conductors and supply cables 22.5 – 300 kV |
G (mm)Supply Conductors and supply cables more 300 - 550 kV |
||
|
1 |
Crossing above tracks of railroads which transport or propose to transport freight cars (max height 15 ft 1in) where not operated by overhead contact wires (a) (b) (c) (d) |
25 ft |
25 ft |
22 ft |
25 ft |
28 ft |
34 ft |
34 ft |
|
2 |
Crossing or paralleling above tracks of railroads operated by overhead trolleys (b) (c) (d) |
26 ft (e) |
26 ft (e) (f) (g) |
19 ft (h) (i) |
27 ft (e) (g) |
30 ft (g) |
34 ft (g) |
34 ft (g) (kk) |
|
3 |
Crossing or along thoroughfares in Urban districts or crossings thoroughfares in rural districts (c) (d) |
18 ft (j) (k) (ii) |
18 ft (j) (l) (m) (ii) |
19 ft (hh) |
20 ft (ii) |
25 ft (n) (o) (ii) |
30 ft (o) (ii) |
30 ft (o) (ii) (kk) |
|
4 |
Above ground along thoroughfares in rural districts or across other areas capable of being transversed by vehicles or agricultural equipment. |
15 ft (k) |
15 ft (m) (n) (p) |
19 ft |
16 ft |
25 ft (n) (o) |
30 ft (o) (p) |
30 ft. (o) (kk) |
|
5 |
Vertical ground in areas accessible to pedestrians only. |
7 ft |
10 ft (m) (q) |
19 ft |
12 ft |
17 ft |
25 ft (o) |
25 ft. (o) (kk) |
|
6 |
Vertical clearance above buildings and bridges (or other structures which do not ordinarily support conductors and on which men can walk) whether attached or unattached. |
8 ft (r) |
8 ft (r) |
8 ft |
8 ft |
12 ft |
12 ft |
20 ft (ll) |
|
7 |
Horizontal clearance of conductor from buildings (except generating and substations), bridges or other structures (upon which men may work) where such conductor is not attached thereto. (a) (t) |
-------------- |
3 ft (u) |
3 ft |
3 ft (u) (v) |
6 ft (v) |
6 ft (v) |
15 ft (v) |
|
8 |
Distance of conductor from center line of pole, wheter attached or unattached (w) (x) (y) |
-------------- |
15 in (a) (aa) |
15 in (aa) (bb) (cc) |
15 in (aa) (o) (dd) |
15 or 18 in (o) (dd) (ee) (jj) |
18 in (dd) (ee) (jj) |
Not Applicable |
|
9 |
Distance of conductor from surface of pole, crossarm or other overhead line structure upon which it is supported, providing it complies with Case 8 above (x) (ee) |
-------------- |
3 in (aa) (ff) |
3 in (aa) (cc) (gg) |
3 in (aa) (dd) (gg) |
3 in (dd) (gg) |
¼ pin spacing shown in Table 2 Case 15 (dd) |
½ pin spacing shown in Table 2 Case 15 (dd) |
|
10 |
Radial centerline clearance of conductor or cable (unattached) from non-climbable street lighting or traffic signal poles or standards, including mastarms, brackets and lighting fixtures. |
------------- |
1 ft (oo) (u) (rr) (ss) |
15 in. (bb) (cc |
3 ft (oo) |
6 ft (pp) |
10 ft (qq) |
10 ft (ll) |
|
11 |
Water areas not suitable for sailboating (tt) (uu) (ww) (xx) |
15 ft |
15 ft |
|
15 ft |
17 ft |
25 ft |
25 ft (kk) |
|
12 |
Water areas suitable for sailboating, surface area of: (tt) (vv) (ww) (xx) (a) Less Than 20 acrea (b) 20 to 200 acres (c) Over 200 to 2,000 acres (d) Over 2,000 acres |
18 ft 26 ft 32 ft 38 ft |
18 ft 26 ft 32 ft 38 ft |
--- --- --- --- |
18 ft 26 ft 32 ft 38 ft |
20 ft 28 ft 34 ft 40 ft |
27 ft 35 ft 41 ft 47 ft |
27 ft (kk) 35 ft (kk) 41 ft (kk) 47 ft (kk) |
(a) Shall not be reduced more than 5% because
of temperature or loading
37
1. Supply Lines 54.4-B1
2. Communication Lines 84.4-B1
(b) Shall be increased for supply conductors
on Suspension insulators, under certain conditions
37
(c) Special clearances are provided for traffic
signal equipment
58.1-C
(d) Special clearances are provided for street
lighting equipment
58.2-B
(e) Based on trolley pole throw of 26 feet.
May be reduced where suitably protected.
1. Supply Guys 56.4-B2
2. Supply cables and messengers 57.4-B2
3. Communication Guys 86.4-B2
4. Communication cables and messengers 87.4-B2
(f) May be reduced depending on height of trolley
contact conductors.
1. Supply Service Drop 54.8-C5
2. Communication service drops 84.8-D5
(g) May be reduced and shall be increased depending
on trolley throw
1. Supply conductors (except service drops) 54.4-B2
2. Communication conductors (except service drops) 84.4-B2
(h) Shall be increase where freight cars are
transported.
1. Trolley contact and feeder conductors 74.4-B1
2. Trolley span wires 77.4-A
(i) May be reduced for trolley contact and span
wires in subways, tunnels and under bridges
1. Trolley contact conductors 74.4-E
2. Trolley span wires 77.4-A
(j) May be reduced at crossings over private
thoroughfares and entrances to private property and over private property.
1. Supply Service drops 54.8-B2
2. Supply Guys 56.4-A
3. Communication service drops 84.8-C2
4. Communication guys 86.4-A
(k) May be reduced along thoroughfares where
not normally accessible to vehicles.
1. Supply Guys 56.4-A1
2. Communication Guys 86.4-A1
(l) May be reduced where within 12 feet of curb
line of public thoroughfares
1. Supply Service drops 54.8-B1
2. Communication service drops 84.8-C1
(m) May be reduced for railways signal cables
under special conditions
84.4-A4
(n) May be reduced in rural districts
1. Supply conductors, 750-20,000 volts, crossing roads or driveways 54.4-A2a
2. Supply conductors, 750-20,000 volts, above agricultural areas and along roads 54.4-A2b
3. Communication conductors along roads 84.4-A2
(o) May be reduced for transformer, regulator
or capacitor leads.
1. Transformer Leads 58.3-B
2. Regulator or Capacitor Leads 58.4-B
(p) May be reduced across arid or mountainous
areas
1. Supply Conductors of more than 22, 500 Volts 54.4-A1
2. Communication conductors 84.4-A1
(q) Shall be increased or may be reduced under
special conditions.
1. Increased for supply service drops on industrial or commercial premises 54.8-B3a
2. Supply service drops on residential premises 54.8-B3b
3. Communication conductors 84.4-A3
4. Increased for Communication service drops on industrial or commercial premises 84.8-C3a
5. Communication service drops on residential premises 84.8-C3b
(r) May be reduced above roofs of buildings
under special conditions
1. Supply overhead guys 56.4-G
2. Supply service drops 54.8-B4
3. Communication overhead guys 86.4-F
4. Communication conductors and cables 84.4-E
5. Communication service drops 84.8-C4
(s) Also applies at fire escapes, etc.
1. Supply Conductors 54.4-H1
2. Supply service drops on industrial or commercial premises 54.8-B4a
3. Supply service drops on residential premises 54.8-B4b
4. Communication Conductor 84.4-E
(t) Special Clearances where attached to buildings,
bridges or other structures
1. Supply conductors of 750-22,500 volts 54.4-H2
2. Trolley Contact Conductors 74.4-E
3. Communication Conductors 84.4- F
(u) Reduced clearances permitted under special
conditions
1. Supply service drops on industrial or commercial premises 54.8-B4a
2. Supply cables, grounded 57.4-G
3. Communication cables beside buildings, etc. 84.4-E
4. Communication conductors under bridges, etc. 84.4-F
5. Communication service drops. 84.8-C4
6. Communication cables passing on non-climable streetlight poles, etc. 84.4-D4a
(v) May be reduced under special conditions.
1. Supply conductors of 750-7500 volts 54.4-H1
2. Supply transformer lead and bus wires where guarded 58.3-B2
(w) May be reduced at angles in lines and transportation
points
1. Supply conductors 54.4-D1
2. Communication Conductors 84.4-D5
(x) May be reduced for suitably protected lateral
or vertical runs.
1. Supply bond wires 53.4
2. Supply ground wires 54.6-B
3. Supply lateral conductors 54.6-C
4. Supply vertical pins 54.6-D
5. Supply risers 54.6-E
6. Communication Ground Wires 84.6-B
7. Communication lateral conductors 84.6-C
8. Communication vertical runs 84.6-D
9. Communication risers 84.6-E
(y) Increased clearances for certain conductors
1. Unattached conductors on colinear lines and crossing lines 32.3
2. Unattached supply conductors 54.4D3
3. Supply Service drops on clearance crossarms 54.8-C2
4. Supply Service drops on pole top extensions 54.8-C3
5. Unattached Supply service drops 54.8-D
6. Communication lines, collinear, conflicting or crossing 84.4-D3
7. Communication conductors passing supply poles and unattached thereto 84.4-D4
8. Communication service drops on clearance crossarms 84.8-D2
9. Communication service drops on pole top extensions 84.8-D3
10. Unattached Communication service drops 84.8-E
(z) Special provisions for police and fire alarm
conductors require increased clearances
92.2
(aa) May be reduced under special provisions.
1. Supply conductors of 0-750 volts in rack configuration 54.4-D5
2. Supply service drops from racks 54.8-F
3. Supply cables and messengers attached to poles 57.4-F
4. Communication conductors on communication poles 84.4-D
5. Communication conductors on crossarms 84.4-D1
6. Communication conductors attached to poles 84.4-D2
7. Communication service drops attached to poles 84.8-B
8. Communication cables and messengers 87.4-D
9. Supply or communication cables and messengers on jointly used poles 92.1-B
10. Communication service drops on pole top extensions 92.1-C
(bb) May be reduced for Class T conductors of
not more than 750 volts and of the same potential and polarity
74.4-D
(cc) Not applicable to trolley span wires 77.4-E
(dd) Special clearances for pole-top and dead-end
construction
1. Conductors dead-ended in vertical configuration on poles 54.4-C4
2. Conductors dead-ended in horizontal configuration 54.4-D7
3. Conductors in pole-top construction 54.4-D8
(ee) Clearance requirements for certain voltage
classifications
54.4-D2
(ff) Not applicable to communication conductors
84.4-D
(gg) Clearance from crossarms may be reduced
for certain conductors
1. Suitably insulated leads to protected runs 54.4-E
2. Leads of 0-5000 volts to equipment 54.4-E
3. Leads of 0-5000 volts to cutouts or switches 58.5-C
(hh) Reduced clearance permitted from temporary
fixtures and lighting circuits 0-300 volts
78.3A(1)
(ii) Special Clearances Required Above Public
and Private Swimming Pools:
1. Supply line conductors 54.4–A4
2. Supply service drops 54.8–B5
3. Communication line conductors 84.4–A5
4. Communication service drops 84.8–C5
5. Supply guys, span wires 56.4–A3
6. Communication guys 86.4–A3
(jj)
May be decreased in partial underground distribution
54.4-D2
(kk)
Shall be increased by 0.025
ft. per kV in excess of 300 kV.
(ll)
Shall
be increased by 0.04 ft per kV in excess of 300 kV.
(mm) proposed clearances to be
submitted tot the CPUC prior to construction for circuits in excess of 550
kV.
(nn) Voltage shown in the table
shall mean line – to – ground voltage for direct current (DC) systems.
(oo) May be reduced for grounded or multi-conductor cables.
1. Grounded cables 57.4-H
2. Multi-Conductor cables 54.10-B6
(pp) May be reduced to 4 feet for voltages below 7,500 volts 54.4-D3
(qq) May be reduced to 6 feet for voltages below 75 kV
(rr) May be reduced for supply service drops 54.8-D1
(ss) May be reduced to communication service drops 84.4-E1
(tt) Where a federal agency or surrogate thereof has issued a crossing permit, clearances of that permit shall govern.
(uu) Or Where sailboating is prohibited and where other boating activities are allowed
(vv) Clearance above contiguous ground shall be 5 feet greater than in cases 11 or 12 for the type of water area served for boat launch facilities and for area contiguous thereto, that are posted, designated or specifically prepared for rigging of sailboats or other watercraft.
(ww) For controlled impoundments, the surface areas and corresponding clearances shall be based upon the high water level. for other waters, the surface area shall be that enclosed by its annual flood level. the clearance over rivers, streams and canals shall be based upon the largest surface areas of any one–mile long segment which includes the crossing. the clearance over a canal, river or stream normally used to provide access for sailboats to a larger body of water shall be the same as that required for the larger body of water
(xx) Water areas are lakes, ponds, reservoirs, tidal waters, rivers, streams and canals without surface obstructions
Final Version
Table 1
Basic Minimum Allowable Vertical Clearance of Wire Above Railroads, Thoroughfares , Ground or Water Surface; Also clearances from Poles, Buildings, Structures or Other Objects(nn)
(Letter References Denote Modifications of Minimum Clearances as Referred to in Note Following this Table)
|
Case No |
Nature of Clearance |
Wire or Conductor Concerned |
||||||
|
A |
B |
C |
D |
E |
F Supply Conductors and supply cables 22.5 – 300 kV |
G (mm)Supply Conductors and supply cables more 300 - 550 kV |
||
|
1 |
Crossing above tracks of railroads which transport or propose to transport freight cars (max height 15 ft 1in) where not operated by overhead contact wires (a) (b) (c) (d) |
25 ft |
25 ft |
22 ft |
25 ft |
28 ft |
34 ft |
34 ft |
|
2 |
Crossing or paralleling above tracks of railroads operated by overhead trolleys (b) (c) (d) |
26 ft (e) |
26 ft (e) (f) (g) |
19 ft (h) (i) |
27 ft (e) (g) |
30 ft (g) |
34 ft (g) |
34 ft (g) (kk) |
|
3 |
Crossing or along thoroughfares in Urban districts or crossings thoroughfares in rural districts (c) (d) |
18 ft (j) (k) (ii) |
18 ft (j) (l) (m) (ii) |
19 ft (hh) |
20 ft (ii) |
25 ft (n) (o) (ii) |
30 ft (o) (ii) |
30 ft (o) (ii) (kk) |
|
4 |
Above ground along thoroughfares in rural districts or across other areas capable of being transversed by vehicles or agricultural equipment. |
15 ft (k) |
15 ft (m) (n) (p) |
19 ft |
16 ft |
25 ft (n) (o) |
30 ft (o) (p) |
30 ft. (o) (kk) |
|
5 |
Vertical ground in areas accessible to pedestrians only. |
7 ft |
10 ft (m) (q) |
19 ft |
12 ft |
17 ft |
25 ft (o) |
25 ft. (o) (kk) |
|
6 |
Vertical clearance above buildings and bridges (or other structures which do not ordinarily support conductors and on which men can walk) whether attached or unattached. |
8 ft (r) |
8 ft (r) |
8 ft |
8 ft |
12 ft |
12 ft |
20 ft (ll) |
|
7 |
Horizontal clearance of conductor from buildings (except generating and substations), bridges or other structures (upon which men may work) where such conductor is not attached thereto. (a) (t) |
-------------- |
3 ft (u) |
3 ft |
3 ft (u) (v) |
6 ft (v) |
6 ft (v) |
15 ft (v) |
|
8 |
Distance of conductor from center line of pole, wheter attached or unattached (w) (x) (y) |
-------------- |
15 in (a) (aa) |
15 in (aa) (bb) (cc) |
15 in (aa) (o) (dd) |
15 or 18 in (o) (dd) (ee) (jj) |
18 in (dd) (ee) (jj) |
Not Applicable |
|
9 |
Distance of conductor from surface of pole, crossarm or other overhead line structure upon which it is supported, providing it complies with Case 8 above (x) (ee) |
-------------- |
3 in (aa) (ff) |
3 in (aa) (cc) (gg) |
3 in (aa) (dd) (gg) |
3 in (dd) (gg) |
¼ pin spacing shown in Table 2 Case 15 (dd) |
½ pin spacing shown in Table 2 Case 15 (dd) |
|
10 |
Radial centerline clearance of conductor or cable (unattached) from non-climbable street lighting or traffic signal poles or standards, including mastarms, brackets and lighting fixtures. |
------------- |
1 ft (oo) (u) (rr) (ss) |
15 in. (bb) (cc |
3 ft (oo) |
6 ft (pp) |
10 ft (qq) |
10 ft (ll) |
|
11 |
Water areas not suitable for sailboating (tt) (uu) (ww) (xx) |
15 ft |
15 ft |
|
15 ft |
17 ft |
25 ft |
25 ft (kk) |
|
12 |
Water areas suitable for sailboating, surface area of: (tt) (vv) (ww) (xx) (a) Less Than 20 acrea (b) 20 to 200 acres (c) Over 200 to 2,000 acres (d) Over 2,000 acres |
18 ft 26 ft 32 ft 38 ft |
18 ft 26 ft 32 ft 38 ft |
--- --- --- --- |
18 ft 26 ft 32 ft 38 ft |
20 ft 28 ft 34 ft 40 ft |
27 ft 35 ft 41 ft 47 ft |
27 ft (kk) 35 ft (kk) 41 ft (kk) 47 ft (kk) |
(a) Shall not be reduced more than 5% because of temperature
or loading 37
(b) Shall be increased for supply conductors on Suspension
insulators, under certain conditions 37
(c) Special clearances are provided for traffic signal
equipment 58.1-C
(d) Special clearances are provided for street lighting
equipment 58.2-B
(e) Based on trolley pole throw of 26 feet. May be
reduced where suitably protected.
1. Supply Guys 56.4-B2
2. Supply cables and messengers 57.4-B2
3. Communication Guys 86.4-B2
4. Communication cables and messengers 87.4-B2
(f) May be reduced depending on height of trolley contact
conductors.
1. Supply Service Drop 54.8-C5
2. Communication service drops 84.8-D5
(g) May be reduced and shall be increased depending on
trolley throw
1. Supply conductors (except service drops) 54.4-B2
2. Communication conductors (except service drops) 84.4-B2
(h) Shall be increase where freight cars are transported.
1. Trolley contact and feeder conductors 74.4-B1
2. Trolley span wires 77.4-A
(i) May be reduced for trolley contact and span wires in
subways, tunnels and under bridges
1. Trolley contact conductors 74.4-E
2. Trolley span wires 77.4-A
(j) May be reduced at crossings over private thoroughfares and entrances to private property and over private property.
1. Supply Service drops 54.8-B2
2. Supply Guys 56.4-A
3. Communication service drops 84.8-C2
4. Communication guys 86.4-A
(k) May be reduced along thoroughfares where not normally
accessible to vehicles.
(l) May be reduced where within 12 feet of curb line of
public thoroughfares
1. Supply Service drops 54.8-B1
2. Communication service drops 84.8-C1
(m) May be reduced for railways signal cables under special
conditions 84.4-A4
(n) May be reduced in rural districts
1. Supply conductors, 750-20,000 volts, crossing roads or driveways 54.4-A2a
2. Supply conductors, 750-20,000 volts, above agricultural areas and along roads 54.4-A2b
3. Communication conductors along roads 84.4-A2
(o) May be reduced for transformer, regulator or capacitor
leads.
1. Transformer Leads 58.3-B
2. Regulator or Capacitor Leads 58.4-B
(p) May be reduced across arid or mountainous areas
1. Supply Conductors of more than 22,500 Volts 54.4-A1
2. Communication conductors 84.4-A1
(q) Shall be increased or may be reduced under special
conditions.
1. Increased for supply service drops on industrial or commercial premises 54.8-B3a
2. Supply service drops on residential premises 54.8-B3b
3. Communication conductors 84.4-A3
4. Increased for Communication service drops on industrial or commercial premises 84.8-C3a
5. Communication service drops on residential premises 84.8-C3b
(r) May be reduced above roofs of buildings under special
conditions
1. Supply overhead guys 56.4-G
2. Supply service drops 54.8-B4
3. Communication overhead guys 86.4-F
4. Communication conductors and cables 84.4-E
5. Communication service drops 84.8-C4
(s) Also applies at fire escapes, etc.
1. Supply Conductors 54.4-H1
2. Supply service drops on industrial or commercial premises 54.8-B4a
3. Supply service drops on residential premises 54.8-B4b
4. Communication Conductor 84.4-E
(t) Special Clearances where attached to buildings, bridges
or other structures
1. Supply conductors of 750-21,000 volts 54.4-H2
2. Trolley Contact Conductors 74.4-E
3. Communication Conductors 84.4-F
(u) Reduced clearances permitted under special conditions
1. Supply service drops on industrial or commercial premises 54.8-B4a
2. Supply cables, grounded 57.4-G
3. Communication cables beside buildings, etc. 84.4-E
4. Communication conductors under bridges, etc. 84.4-F
5. Communication service drops. 84.8-C4
(v) May be reduced under special conditions.
1. Supply conductors of 750-7500 volts 54.4-H1
2. Supply transformer lead and bus wires where guarded 58.3-B2
(w) May be reduced at angles in lines and transportation
points
1. Supply conductors 54.4-D1
2. Communication Conductors 84.4-D5
(x) May be reduced for suitably protected lateral or vertical
runs.
1. Supply bond wires 53.4
2. Supply ground wires 54.6-B
3. Supply lateral conductors 54.6-C
4. Supply vertical pins 54.6-D
5. Supply risers 54.6-E
6. Communication Ground Wires 84.6-B
7. Communication lateral conductors 84.6-C
8. Communication vertical runs 84.6-D
9. Communication risers 84.6-E
(y) Increased clearances for certain conductors
1. Unattached conductors on colinear lines and crossing lines 32.3
2. Unattached supply conductors 54.4-D3
3. Supply Service drops on clearance crossarms 54.8-C2
4. Supply Service drops on pole top extensions 54.8-C3
5. Unattached Supply service drops 54.8-D
6. Communication lines, collinear, conflicting or crossing 84.4-D3
7. Communication conductors passing supply poles and unattached thereto 84.4-D4
8. Communication service drops on clearance crossarms 84.8-D2
9. Communication service drops on pole top extensions 84.8-D3
10. Unattached Communication service drops 84.8-E
(z) Special provisions for police and fire alarm conductors
require increased clearances 92.2
(aa) May be reduced under special provisions.
1. Supply conductors of 0-750 volts in rack configuration 54.4-D5
2. Supply service drops from racks 54.8-F
3. Supply cables and messengers attached to poles 57.4-F
4. Communication conductors on communication poles 84.4-D
5. Communication conductors on crossarms 84.4-D1
6. Communication conductors attached to poles 84.4-D2
7. Communication service drops attached to poles 84.8-B
8. Communication cables and messengers 87.4-D
9. Supply or communication cables and messengers on jointly used poles 92.1-B
10. Communication service drops on pole top extensions 92.1-C
(bb) May be reduced for Class T conductors of not more
than 750 volts and of the same potential and polarity 74.4-D
(cc) Not applicable to trolley span wires 77.4-E
(dd) Special clearances for pole-top and dead-end construction
1. Conductors dead-ended in vertical configuration on poles 54.4-C4
2. Conductors dead-ended in horizontal configuration 54.4-D7
3. Conductors in pole-top construction 54.4-D8
(ee) Clearance requirements for certain voltage classifications
54.4-D2
(ff) Not applicable to communication conductors
84.4-D
(gg) Clearance from crossarms may be reduced for certain
conductors
1. Suitably
insulated leads to protected runs 54.4-E
2. Leads of 0-5000 volts to equipment 54.4-E
3. Leads of 0-5000 volts to cutouts or switches 58.5-C
(hh) Reduced clearance permitted from temporary fixtures
and lighting circuits 0-300 volts 78.3-A(1)
(ii) Special Clearances Required Above Public and Private
Swimming Pools:
1. Supply line conductors 54.4–A4
2. Supply service drops 54.8–B5
3. Communication line conductors 84.4–A5
4. Communication service drops 84.8–C5
5. Supply guys, span wires 56.4–A3
6. Communication guys 86.4–A3
(jj) May be decreased in partial underground distribution 54.4-D2
(kk) Shall be increased by 0.025 ft. per kV in excess of 300 kV.
(ll) Shall be increased by 0.04 ft. per kV in excess of 300 kV.
(mm) proposed clearances to be submitted tot the CPUC prior to construction for circuits in excess of 550 kV.
(nn) Voltage shown in the table shall mean line – to – ground voltage for direct current (DC) systems.
(oo) May be reduced for grounded or multi-conductor cables.
(pp) May be reduced to 4 feet for voltages below 7,500 volts 54.4-D3
(qq) May be reduced to 6 feet for voltages below 75 kV
(rr) May be reduced for supply service drops 54.8-D1
(ss) May be reduced to communication service drops 84.4-E1
(tt) Where a federal agency or surrogate thereof has issued a crossing permit, clearances of that permit shall govern.
(uu) Or Where sailboating is prohibited and where other boating activities are allowed
(vv) Clearance above contiguous ground shall be 5 feet greater than in cases 11 or 12 for the type of water area served for boat launch facilities and for area contiguous thereto, that are posted, designated or specifically prepared for rigging of sailboats or other watercraft.
(ww) For controlled impoundments, the surface areas and corresponding clearances shall be based upon the high water level. for other waters, the surface area shall be that enclosed by its annual flood level. the clearance over rivers, streams and canals shall be based upon the largest surface areas of any one–mile long segment which includes the crossing. the clearance over a canal, river or stream normally used to provide access for sailboats to a larger body of water shall be the same as that required for the larger body of water
(xx) Water areas are lakes, ponds, reservoirs, tidal waters, rivers, streams and canals without surface obstructions