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FUSE COORDINATION




Underground Electric Distribution Standards

Revised: February 20, 2008
Revised By: SGL
Approved By: KKR
SYSTEM PROTECTION
SP - 1
FUSE COORDINATION
GENERAL
The purpose of protective coordination is to provide isolation of a fault as close to the fault as possible so that
a minimum of customers will be affected. The workhorse of the JEA protection scheme is the fuse. By
following the fuse tables given in this section, the fuse closest to a fault will melt first providing proper
coordination and fault isolation.
The fuse tables are divided into three major groups:
GROUP A: LATERAL FUSING presents the required fuses for the fusing of laterals and sub-laterals. Tables
for overhead and underground laterals behind substation breakers and reclosers are given for each system
voltage.
GROUP B: EQUIPMENT PROTECTION FUSING gives the fuse sizes for the protection of transformers and
capacitors.
GROUP C: FUSE-FUSE COORDINATION presents various tables for coordinating one type of fuse link
behind another type of fuse link.
In order to maintain a properly functioning fuse coordination system, the fuse tables presented in this section
must be followed in both system design and maintenance.
If an installed fuse will not hold the connected load and a larger fuse is installed, the party installing the larger
size fuse shall notify the USC System Analysis Process of (1) the location, (2) the old fuse size, and (3) the
new fuse size.
If a fuse is replaced with a different size fuse because the required size was not available, the party installing
the different size fuse shall notify the Systems Operation Control Center so the proper size fuse can be
reinstalled.





Underground Electric Distribution Standards

Revised: February 20, 2008
Revised By: SGL
Approved By: KKR
SYSTEM PROTECTION
SP - 2
GROUP A: LATERAL FUSING
GENERAL COMMENTS
Overhead Laterals on Private Property:
1.

Fuse the lateral at the road with the correct size lateral fuse if the lateral meets ANY of the following
conditions:
1.1.

More than one transformer is served.
1.2.

The lateral is longer than two spans.
1.3.

The transformer pole cannot be seen from the cutout at the road.
1.4.

Trees could cause outage problems.
2.

Fuse the lateral at the road with the correct size transformer fuse if the lateral meets ALL of the
following conditions:
2.1.

Only one transformer is served.
2.2.

The lateral is two spans or less in length.
2.3.

The transformer pole can be seen from the cutout at the road.
2.4.

Trees will not cause any outage problems.
Underground Laterals:
1.

Fuse the lateral at the tap with the correct size lateral fuse if the lateral meets ANY of the following
conditions:
1.1.

The tap occurs in an underground fusing cabinet.
1.2.

The transformer served is equipped with bay-o-net fuses.
1.3.

More than one transformer is served.
1.4.

There are provisions for extending the lateral.
2.

Fuse the lateral at the tap with the correct size transformer fuse if the lateral meets ALL of the
following conditions:
2.1.

The fused tap consists of overhead cutout(s).
2.2.

The transformer served is not equipped with bay-o-net fuses.
2.3.

Only one transformer is served.
2.4.

The lateral is a radial without provisions for extension.
Fusing Behind Sectionalizers:
Sectionalizers do not have time-current characteristics and therefore do not affect coordination between
a fuse and an upstream breaker or recloser. When selecting fuses behind a sectionalizer, the presence
of the sectionalizer should be ignored.




Underground Electric Distribution Standards

Revised: February 20, 2008
Revised By: SGL
Approved By: KKR
SYSTEM PROTECTION
SP - 3
GROUP A: LATERAL FUSING -- 15.2/26.4kV DISTRIBUTION SYSTEM
NOTES:
1.

In the event that the tap off the main line fuse or sublateral fuse does not provide adequate current
carrying capacity, notify the USC System Analysis Process.
2.

A * denotes single phase hydraulic reclosers taken over as part of Okefenokee takeover and are
being temporarily used on JEAs system. For coordination purposes, ignore the existence of these
reclosers.
3.

TABLE 3:
3.1.

The fuse size listed in this table is only for a tap off the main line feeder. The first sublateral
fuse (Overhead) will be half or the next smaller standard size that JEA has in stock. For
example: If a tap off the main line is a 65T fuse, then the first sublateral fuse will be a 30T,
and the second sublateral fuse will be a 15T. See Table 1, Group C, for the first sublateral
and second sublateral fuse off a cable pole.
TABLE 1: OVERHEAD LATERAL & CABLE POLE FUSING (T-LINK)
26.4 kV System Behind Station Breaker

CONDUCTOR SIZE
TAP OFF MAIN LINE 1ST SUB-LATERAL FUSE
2ND SUB-LATERAL FUSE
1/0 AL. or 2 CU. or 2 AL.
100T
50T
25T
4 CU.
80T
40T
20T
4 AL. OR 6 CU.
or Smaller
65T 30T
15T
CABLE POLE
1/0 AL. CABLE or Smaller
100T
SIZE PER TABLE 1
GROUP C - (1)
SIZE PER TABLE 1
GROUP C - (1)


TABLE 2: UNDERGROUND LATERAL FUSING (E-LINK)
26.4 kV System Behind Station Breaker

CABLE SIZE
TAP OFF MAIN LINE 1ST SUB-LATERAL FUSE
2ND SUB-LATERAL FUSE
1/0 AL. OR SMALLER
150E
100E
50E






Underground Electric Distribution Standards

Revised: February 20, 2008
Revised By: SGL
Approved By: KKR
SYSTEM PROTECTION
SP - 4
TABLE 3: OVERHEAD LATERAL & CABLE POLE FUSING (T-LINK)
26.4 kV System Behind Recloser TAP OFF MAIN LINE

RECLOSER
NUMBER
CONDUCTOR
1/0 AL., 2 AL., 2 CU.
CONDUCTOR
4 CU.
CONDUCTOR
4 AL., 6 CU.
CABLE POLE
1/0 AL. OR SMALLER
R-1 80T 80T 65T 80T
R-2 80T 80T 65T 80T
R-3 UNASSIGNED



R-4 UNASSIGNED



R-5 100T 80T 65T 100T
R-6 100T 80T 65T 100T
R-7 100T 80T 65T 100T
R-8 80T 80T 65T 80T
R-9 80T 80T 65T 80T
R-10 UNASSIGNED



R-11 80T 80T 65T 80T
R-12 100T 80T 65T 100T
R-13 80T 80T 65T 80T
R-14 100T 80T 65T 100T
R-15 100T 80T 65T 100T
R-16 80T 80T 65T 80T
R-17 100T 80T 65T 100T
R-18 100T 80T 65T 100T
R-19 80T 80T 65T 80T
R-20 80T 80T 65T 80T
R-21 80T 80T 65T 80T
R-22 100T 80T 65T 100T
R-23 100T 80T 65T 100T
R-24 100T 80T 65T 100T
R-25 UNASSIGNED



R-26 100T 80T 65T 100T
R-27 100T 80T 65T 100T
R-28 100T 80T 65T 100T
R-29 50T 50T 50T 50T
R-30 50T 50T 50T 50T
R-31 50T 50T 50T 50T
R-32 25T 25T 25T 25T
R-33 *
TEMPORARY



R-34 65T 65T 65T 65T
R-35 65T 65T 65T 65T
R-36 30T 30T 30T 30T
R-37 25T 25T 25T 25T
R-38 25T 25T 25T 25T
R-39 25T 25T 25T 25T
R-40 *
TEMPORARY



R-41 *
TEMPORARY



R-42 *
TEMPORARY



R-43 25T 25T 25T 25T
R-44 65T 65T 65T 65T
R-45 65T 65T 65T 65T




Underground Electric Distribution Standards

Revised: February 20, 2008
Revised By: SGL
Approved By: KKR
SYSTEM PROTECTION
SP - 5
TABLE 4: UNDERGROUND LATERAL FUSING (E-LINK)
26.4kV System, Behind Recloser

RECLOSER
NUMBER
TAP OFF MAIN LINE
1
ST

SUBLATERAL
2
ND

SUBLATERAL
R-1 100E 50E 25E
R-2 100E 50E 25E
R-3 UNASSIGNED

R-4 UNASSIGNED

R-5 150E 100E
50E
R-6 150E 100E
50E
R-7 150E 100E
50E
R-8 100E 50E 25E
R-9 100E 50E 25E
R-10 UNASSIGNED

R-11 100E 50E 25E
R-12 150E 100E 50E
R-13 100E 50E 25E
R-14 150E 100E 50E
R-15 150E 100E 50E
R-16 100E 50E 25E
R-17 150E 100E 50E
R-18 150E 100E 50E
R-19 100E 50E 25E
R-20 100E 50E 25E
R-21 100E 50E 25E
R-22 150E 100E 50E
R-23 150E 100E 50E
R-24 150E 100E 50E
R-25 UNASSIGNED

R-26 150E 100E 50E
R-27 150E 100E 50E
R-28 150E 100E 50E
R-29 50E 25E 15E
R-30 50E 25E 15E
R-31 50E 25E 15E
R-32 40E 20E 15E
R-33 *
TEMPORARY

R-34 100E 50E 25E
R-35 100E 50E 25E
R-36 50E 25E 15E
R-37 40E 20E 15E
R-38 40E 20E 15E
R-39 40E 20E 15E
R-40 *
TEMPORARY

R-41 *
TEMPORARY

R-42 *
TEMPORARY

R-43 40E 20E 15E
R-44 80E 50E 25E
R-45 80E 50E 25E




Underground Electric Distribution Standards

Revised: February 20, 2008
Revised By: SGL
Approved By: KKR
SYSTEM PROTECTION
SP - 6
GROUP B: EQUIPMENT PROTECTION FUSING
TABLE 1: LINE CAPACITOR BANK FUSING

3-PHASE BANK
KVAR
SYSTEM VOLTAGE
2.4/4.16 kV
SYSTEM VOLTAGE
15.2/26.4 kV
150 25T
300 50T
600 100T 15T
1200
25T


TABLE 2: TRANSFORMER FUSING -- 15.2/26.4 kV

TRANSFORMER
FUSE LINKS OVERHEAD (1)
BAY-O-NET FUSES
UNDERGROUND
KVA
1-PHASE
OH/UG
KVA
3 PHASE
PADS
FULL
LOAD
AMPS
JEA
ITEM ID
CHANCE
TYPE
KEARNEY
TYPE
COOPER
TYPE
JEA
ITEM ID
RTE
TYPE
5

.33
FUS OH 019
0.4 SF
1/2 X
10
.66
FUS OH 020
0.7 SF
1 X
15
.99
FUS OH 021
1.0 SF
1-1/2 X
25
1.65
FUS OH 022
1.6 SF
2-1/2 X
FUS UG 021
C3
37.5
2.47
FUS OH 023
2.1 SF
3-1/2 X
50
3.29
FUS OH 024
3.1 SF
4 X