SOUTHWEST LOUISIANA ELECTRIC MEMBERSHIP COORPORATION
COMMERCIAL SERVICE
REQUIREMENTS
Engineering Service Specifications
Table of Contents
Commercial Transformer Foundation Details
Three-Phase Pad Specifications - Diagram .............................................................................................................22
Transformer Foundations Dimensions Table ...........................................................................................................23
Commercial Current Transformer Metering Schemes
Padmount Transformer Three-Phase Commercial Connections – Diagram............................................................24
Specifications for Padmount Transformer Three-Phase Commercial Connections.................................................25
Padmount Transformer 3-Phase Commercial Connections and Single-Phase Commercial – Diagram .................27
Specifications for Padmount Transformer 3-Phase Commercial Connections and Single-Phase Commercial ......28
Overhead Source Single-Phase or Three-Phase – Diagram ...................................................................................30
Specifications for Overhead Source Single-Phase or Three-Phase ........................................................................31
Overhead Source to Panel Board Three-Phase with CTs in Enclosure – Diagram.................................................33
Specifications for Overhead Source to Panel Board Three-Phase with CTs in Enclosure ......................................34
Three-Phase Overhead Self-Contained Metering on Building – Diagram ...............................................................36
Specifications for Three-Phase Overhead Self-Contained Metering on Building ....................................................37
Engineering Service Specifications
Commercial Transformer Foundation Details
22
MATERIAL LIST
UM1-14A & UM1-14B
UM1-14A
REA NO. ITEM
A
B
C
D
E
F
G
H
P
16522013 AV
16524013 AV
17312000
I
53818508 AI
76001940
J
76211008
K
76401010
L
78400040
M
DESCRIPTION
SIDE OF FOUNDATION FORM
SIDE OF FOUNDATION FORM
SIDE OF WINDOW
SIDE OF WINDOW
DISTANCE FFROM EDGE OF FORM
SIDE OF REINFORCED FRAME
SIDE OF REINFORCED FRAME
CENTERLINE OF WINDOW
CONNECTOR AS REQUIRED
2/0-19 STR. BARE COPPER --FEET
4/0-19 STR. BARE COPPER --FEET
5/8" GRD ROD CLAMP **EX**
5/8" X 8' COPPERWELD GRD ROD
1" PVC CONDUIT
1" 90 DEG PVC ELBOW **EX**
1" PVC COUPLING
**EX**
CONCRETE -CU. YARD- EX
UM1-14B
75
150
225
300
500
750 1000 2500
KVA
108"
108"
44"
13"
6"
100"
100"
54"
6
45
KVA
108"
108"
44"
13"
6"
100"
100"
54"
6
45
KVA
108"
108"
44"
13"
6"
100"
100"
54"
6
45
KVA
108"
108"
44"
13"
6"
100"
100"
54"
6
45
KVA
108"
108"
44"
13"
6"
100"
100"
54"
6
KVA
108"
108"
44"
13"
6"
100"
100"
54"
6
KVA
108"
108"
60"
20"
14"
100"
100"
54"
6
KVA
108"
108"
60"
20"
14"
100"
100"
54"
6
45
45
45
45
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
10
10
10
10
10
10
10
10
1
1
1
1
1
1
1
1
2
2
2
2
2
2
2
2
2 1/4 2 1/4 2 1/4 2 1/4 2 1/4 2 1/4 2 1/4 2 1/4
23
NOTE: SLEMCO's Field Engineer may vary
the dimensions of the foundation based on
the size of the transformer and site
conditions.
* CPR - ( 1) TRANSFORMER PAD 3 PH CONCRETE (M36810040)
3-PHASE 75, 150, 25, 300, 500, 750, 1000, & 2500 KVA
PADMOUNT TRANSFORMER FOUNDATION
UM1-14A
UM1-14B
APPROVED
PAGE NO.
R:\SPECS\UNDERGROUND\MISC\UM1-14A.MAT.XLS 11/26/2012
DATE
Engineering Service Specifications
Commercial Current Transformer Metering Schemes
24
C.T. METERING SPECIFICATIONS
3-PHASE SINGLE CUSTOMER SERIVCE
FROM UNDERGROUND TRANSFORMER
A.
Primary cable furnished and installed by SLEMCO.
B.
Three (3) two inch (2”) primary conduit or per SLEMCO specifications furnished and
installed by customer to overhead terminal pole. Conduit risers must be Schedule 80 PVC
or steel pipe. Customer must also place pull wire or rope inside of all conduits.
C.
Transformer furnished and installed by SLEMCO.
D.
Transformer foundation constructed and grounded by customer. (See SLEMCO
Padmount Transformer Foundation Specifications). SLEMCO must inspect foundation
before concrete is poured.
E.
Secondary conduit and cable installed by customer as required by load. Conduit risers
must be Schedule 80 PVC or steel pipe.
F.
Meter enclosure furnished by SLEMCO and installed on outside of building by customer or
on rack next to transformer.
G.
One inch (1”) metering conduit from meter enclosure to transformer pad furnished and
installed by customer. (See SLEMCO Transformer Padmount Foundation Specifications).
One inch (1”) conduit from padmount to (C.T.) meter enclosure is to be continuous and
inaccessible (L.B. cannot be used).
H.
Current transformers (C.T.’s) furnished by SLEMCO and installed by SLEMCO in the
secondary compartment of the padmount transformer.
I.
Main disconnect and wire trough furnished and installed by customer on panel board as
required by N.E.C. Main is required with over six disconnects.
J.
Meter base grounding, minimum #6 S.D. Copper in PVC to the ground rod, furnished and
installed by customer.
K.
Ground rods, minimum of (2) 5/8 in. x 8 ft. copper weld or (2) ½ in. x 8 ft. copper,
furnished and installed by customer. Must have one ground rod per every 200 amps of
service. Ground rods shall be installed 6 ft. apart. Ground rod is to be set 1 inch below
finished grade.
L.
Main ground wire shall be minimum #2 insulated copper (sized according to N.E.C.) and
shall run continuous from grounding buss to ground rods and installed in ½ in. conduit.
Ground wire should be sized according to load and may need to be increased to 1/0, 4/0 or
larger if needed.
25
C.T. METERING SPECIFICATIONS
3-PHASE SINGLE CUSTOMER SERIVCE
FROM UNDERGROUND TRANSFORMER
NOTES:
1.
J, K, and L above are minimum requirements by SLEMCO; additional grounding may be
required by N.E.C. or by local authorities of inspection.
2.
Termination of cables on source side will be made by SLEMCO in padmount transformer.
Termination of cables on load side will be made by customer in wire trough or main
disconnect on building.
3.
For pole type underground services, only Letters “E” through “K” will apply.
4.
Variations of this design will be considered equal as long as National Electrical Code
requirements are met.
5.
Inspection: If a governing authority requires an inspection, tag must be in place and
marked approved before SLEMCO will connect service.
6.
Prior to secondary service connection and meter installation, a SLEMCO serviceman must
inspect the total job for readiness. When ready for this inspection, call the Lafayette
Service Department at 896-5551 and advise.
7.
In any case where SLEMCO furnishes secondaries and C.T. metering is involved, a wire
trough must be furnished by the customer in order to make terminations as no splices are
to be made in the C.T. enclosure.
8.
A maximum of three (3), 90° turns are allowed in the primary conduit without requiring a
pull box.
9.
90° turns must be rigid, no PVC, with a minimum long radius turn of twenty-eight inches
(28”).
10.
A minimum of forty-eight inches (48”) of tail of secondary service cable should be left in
secondary section of transformers.
11.
SLEMCO does not allow the meter enclosure to be mounted on the side of the padmounted
transformers; therefore, if it is not mounted with the service equipment, it should be
mounted on a stand or rack adjacent to the transformer as per SLEMCO specifications.
26
27
C.T. METERING SPECIFICATIONS
3-PHASE MULTIPLE SERVICE OR 1-PHASE COMMERCIAL
SERVICE FROM UNDERGROUND TRANSFORMER
A.
Primary cable furnished and installed by SLEMCO.
B.
Three (3) two inch (2”) primary conduit or per SLEMCO specifications. Conduit risers
must be Schedule 80 PVC or steel pipe.
C.
Transformer furnished and installed by SLEMCO.
D.
Transformer foundation constructed and grounded by customer. (See SLEMCO
Padmount Transformer Foundation Specifications). SLEMCO must inspect foundation
before concrete is poured.
E.
Secondary conduit and cable installed by customer as required by load. Conduit risers
must be Schedule 80 PVC or steel pipe.
F.
Meter enclosure furnished by SLEMCO and installed on outside of building or on rack next
to transformer by customer.
G.
One inch (1”) metering conduit from meter enclosure to C.T. enclosure, and C.T.
enclosure furnished and installed by customer. C.T. enclosure must be installed on
building or on rack next to transformer depending on distance of transformer from the
building. C.T. enclosure shall be sized according to wire size, but shall be no smaller that
24” x 24” x 10” and must be lockable tab.
H.
Current transformers (C.T.’s) furnished by SLEMCO and installed by customer in the C.T.
enclosure as specified above.
I.
Main disconnect and wire trough furnished and installed by customer on panel board as
required by N.E.C. Main is required with over six disconnects.
J.
Ground wire will be a minimum of a continuous #6 soft drawn copper or #6 insulated
copper and will run from meter socket to CT enclosure to a grounding buss bar inside of the
trough.
K.
Main ground wire shall be minimum #2 insulated copper (sized according to N.E.C.) and
shall run continuous from grounding buss to ground rods and installed in ½ in. conduit.
Ground wire should be sized according to load and may need to be increased to 1/0, 4/0 or
larger if needed.
L.
Ground rods, minimum of (2) 5/8 in. x 8 ft. copper weld or (2) ½ in. x 8 ft. copper,
furnished and installed by customer. Must have one ground rod per every 200 amps of
service. Ground rods shall be installed 6 ft. apart. Ground rod is to be set 1 in. below
finished grade.
28
C.T. METERING SPECIFICATIONS
3-PHASE MULTIPLE SERVICE OR 1-PHASE COMMERCIAL
SERVICE FROM UNDERGROUND TRANSFORMER
NOTES:
1.
J, K, and L above are minimum requirements by SLEMCO; additional grounding may be
required by N.E.C. or by local authorities of inspection.
2.
Termination of cables on source side will be made by SLEMCO in padmount transformer.
Termination of cables on load side will be made by customer in wire trough or main
disconnect on building.
3.
Variations of this design will be considered equal as long as National Electrical Code
requirements are met.
4.
Inspection: If a governing authority requires an inspection, tag must be in place and
marked approved before SLEMCO will connect service.
5.
Prior to secondary service connection and meter installation, a SLEMCO serviceman must
inspect the total job for readiness. When ready for this inspection, call the Lafayette
Service Department at 896-5551 and advise.
6.
In any case where SLEMCO furnishes secondary and C.T. metering is involved, a wire
trough must be furnished by the customer in order to make terminations as no splices are
to be made in the C.T. enclosure.
7.
A maximum of three (3), 90° turns are allowed in the primary conduit without requiring a
pull box.
8.
90° turns must be rigid, no PVC, with a minimum long radius turn of twenty-eight inches
(28”).
9.
A minimum of forty-eight inches (48”) of tail of secondary service cable should be left in
secondary section of transformers.
10.
SLEMCO does not allow the meter enclosure to be mounted on the side of the padmounted
transformers; therefore, if it is not mounted with the service equipment, it should be
mounted on a stand or rack adjacent to the transformer as per SLEMCO specifications.
29
30
C.T. METERING SPECIFICATIONS
1 PHASE OR 3 PHASE COMMERCIAL
UNDERGROUND FROM OVERHEAD SOURCE
A.
Secondary cable furnished and installed by customer as required by load. Termination of
cables must be made in wire trough or main disconnect by customer on outside of building.
B.
Secondary conduit furnished and installed by customer as designated by SLEMCO.
Conduit risers must be schedule 80 PVC or steel pipe sized according to wire size and
N.E.C.
C.
Meter socket furnished by SLEMCO and installed by customer. Must be mounted between
5 ft. and 6 ft. in height. Socket cannot be mounted to the siding of a metal building unless
additional support is used behind the socket. The top hole of socket must be plugged with 1
in. plug if applicable.
D.
Current transformer – CT(s) furnished by SLEMCO. Must be mounted to back of CT
enclosure by customer.
E.
CT enclosure is to be supplied by customer and must be a minimum of 24” x 24” x 10”
Enclosure must have a way to secure the door with a SLEMCO padlock. When installed,
CT enclosure shall be at a height of 2 to 4 feet from the ground to the bottom of the CT
enclosure.
F.
Conduit from CT enclosure to meter socket is to be 1 in. schedule 40 PVC. LB’s and flex
conduit cannot be used.
G.
Ground wire will be a minimum of a continuous #6 soft drawn copper or #6 insulated
copper and will run continuous from meter socket to CT enclosure to a grounding buss bar
inside of the trough. Ground lug will be installed by customer to CT enclosure and must be
attached with a nut and bolt.
H.
Main ground wire shall be minimum #2 insulated copper (sized according to N.E.C.) and
shall run continuous from grounding buss to ground rods and installed in ½ in. conduit.
Ground wire should be sized according to load and may need to be increased to 1/0, 4/0 or
larger if needed.
I.
Ground rods, minimum of (2) 5/8 in. x 8 ft. copper weld or (2) ½ in. x 8 ft. copper,
furnished and installed by customer. Must have one ground rod per every 200 amps of
service. Ground rods shall be installed 6 ft. apart. Ground rod is to be set 1 in. below
finished grade.
J.
Wire trough and main disconnect shall be installed by customer as per N.E.C. and all
terminations will be made in trough or to main disconnect by customer. No connections
are made in CT enclosure.
31
C.T. METERING SPECIFICATIONS
1 PHASE OR 3 PHASE COMMERCIAL
UNDERGROUND FROM OVERHEAD SOURCE
NOTES:
1.
G, H, and I above are minimum requirements by SLEMCO: additional grounding may be
required by N.E.C. or by local authorities of inspection.
2.
Variations of this design will be considered equal as long as National Electric Code
requirements are met.
3.
Inspection: If a governing authority requires an inspection, tag must be in place and
marked approved before SLEMCO will connect service.
4.
Prior to secondary service connection and meter installation, a SLEMCO serviceman must
inspect the total job for readiness. When ready for this inspection, call the Lafayette
Service Department at 896-5551 and advise.
5.
In any case where SLEMCO furnishes secondaries and C.T. metering is involved, a wire
trough or main disconnect must be furnished by the customer in order to make terminations
as no splices are to be made in the C.T. enclosure.
6.
A minimum of 3, 90° turns are allowed in the primary conduit without requiring a pull box.
7.
90° turns must be rigid, no PVC, with a minimum long radius turn of 28 inches.
8.
A minimum of 48 inches of tail of secondary service cable should be left in secondary
section of transformers.
32
33
C.T. METERING SPECIFICATIONS
3 PHASE OVERHEAD C.T.’S ON PANEL BOARD
WITH C.T.’S IN ENCLOSURE
A.
Secondary cable furnished and installed by SLEMCO.
B.
Service mast with weatherhead and insulator cable support furnished and installed by
customer.
C.
Secondary conduit and cable installed by customer as required by load. Conduit risers
must be Schedule 80 PVC or steel pipe with a 3-strap minimum.
D.
Main disconnect and wire trough furnished and installed by customer on panel board as
required by N.E.C. Main is required with over six disconnects.
E.
Meter enclosure furnished by SLEMCO and installed on panel board by customer.
F.
Meter base and CT enclosure grounding, minimum #6 S.D. copper or #6 insulated
copper and will run continuous from meter socket to CT enclosure to grounding buss bar in
the trough.
G.
Ground rods, minimum of (2) 5/8 in. x 8 ft. copper weld or (2) ½ in. x 8 ft. copper,
furnished and installed by customer. Must have one ground rod per every 200 amps of
service. Ground rods shall be installed 6 ft. apart. Ground rod is to be set 1 in. below
finished grade.
H.
Main ground wire shall be minimum #2 insulated copper (sized according to N.E.C.) and
shall run continuous from grounding buss to ground rods and installed in ½ in. conduit.
Ground wire should be sized according to load and may need to be increased to 1/0, 4/0 or
larger if needed.
I.
Current transformers (C.T.’s) furnished by SLEMCO and installed by customer; C.T.’s
must be rigidly mounted within the C.T. enclosure.
J.
Mount equipment on a permanent type metal structure size indicated by equipment. See
SLEMCO Meter Pole Specifications for pole requirements.
K.
Current transformer enclosure with one inch (1”) conduit from meter enclosure furnished
and installed on panel board by customer. Enclosure must have locking tab on it in order to
install padlock and must be a minimum of 24” x 24” x 10”. One inch (1”) conduit from C.T.
enclosure to C.T. meter enclosure is to be continuous and inaccessible (L.B. cannot be
used).
34
C.T. METERING SPECIFICATIONS
3 PHASE OVERHEAD C.T.’S ON PANEL BOARD
WITH C.T.’S IN ENCLOSURE
NOTES:
1.
F, G, and H above are minimum requirements by SLEMCO; additional grounding may be
required by N.E.C. or by local authorities of inspection.
2.
Variations of this design will be considered equal as long as National Electrical Code
requirements are met.
3.
Inspection: If a governing authority requires an inspection, tag must be in place and
marked approved before SLEMCO will connect service.
4.
Prior to secondary service connection and meter installation, a SLEMCO serviceman must
inspect the total job for readiness. When ready for this inspection, call the Lafayette
Service Department at 896-5551 and advise.
35
36
C.T. METERING SPECIFICATIONS
3 PHASE OVERHEAD SELF-CONTAINED METERING ON BUILDING
A.
Secondary cable furnished and installed by SLEMCO.
B.
Customer will furnish and install service mast with weatherhead and insulator cable
support.
C.
Secondary conduit and cable installed by customer as required by load. Conduit riser
must be Schedule 80 PVC or steel pipe, with a 3-strap minimum.
D.
Main disconnects furnished and installed by customer on outside of building as required
by N.E.C.
E.
Meter enclosure furnished by SLEMCO and installed on outside of building by customer.
F.
Meter base grounding, minimum #6 S.D. Copper in PVC to the ground rod, furnished and
installed by customer.
G.
Ground rods, minimum 5/8 in. x 8 ft. copper weld or ½ in. x 8 ft. copper, furnished and
installed by customer. Ground rod is to be set 1 in. below finished grade.
NOTES:
1.
F and G above are minimum requirements by SLEMCO; additional grounding may be
required by N.E.C. or by local authorities of inspection.
2.
Variations of this design will be considered equal as long as National Electrical Code
requirements are met.
3.
Inspection: If a governing authority requires an inspection, tag must be in place and
marked approved before SLEMCO will connect service.
4.
Prior to secondary service connection and meter installation, a SLEMCO serviceman must
inspect the total job for readiness. When ready for this inspection, call the Lafayette
Service Department at 896-5551 and advise.
37