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 This section covers several categories pertaining to the installation
and use of our cable. Including:
- Jamming
- Minimum Bending Radii
- Maximum Pulling Tensions
- Cable Sidewall Pressure
- Cable Preparation and D.C. Hi-Pot
Testing Procedure
- Cable End Preparation
- Cable Storage Procedure
JAMMING
Jamming is the wedging of three or more cables
as they are pulled into a conduit. This usually occurs as a result
of cross-overs when the cables are twisted or are pulled around
bends in the conduit. Jam ratio is defined as the ratio of conduit
inner diameter (D) to the cable outside diameter (d).

Probability of Jamming
Jamming Probability Using Jam Ratio

The oval cross section of
conduit bends was accounted for with a 5% factor.
Note: Measured cable diameters
should be used to determine the jam ratio since actual cable diameters
vary from published values.
MINIMUM BENDING
RADII
These factors apply to the minimum values
for the radii to which insulated cables may be bent for permanent
training during installation. These limits do not apply to conduit
bends, sheaves, or other curved surfaces around which the cable
may be pulled under tension while being installed. In all cases
the minimum radii specified referes to the inner surface of the
cable and not to the axis of the cable. These factors apply only
as noted. Additional constructions are covered under the appendix
of ICEA S-93-639, ICEA S-95-658, and ICEA S-96-659.
- A. Power Cables Without Metallic
Shielding or Without Armor
- The minimum bending radii for both
single and multi-conductor cables with or without lead sheath
and without metallic shielding are as follows:
| Thickness of Conductor Insulation in Mils 155
and Less |
| Overall Diameter of Cable
Inches |
| 1.000 and Less |
1.001 to 2.000 |
2.001 and Over |
| 4 |
5 |
6 |
- Power Cables Over 600
Volts, Non-Shielded, Non-Armored:
- The minimum bending radius
for all cables is eight times the overall cable diameter.
- Power Cables Over 600
Volts, Shielded or Lead Covered:
- The minimum bending radius
for all cables is twelve times the overall cable diameter.
- Interlocked Armored Cables,
All Voltages:
- For Non-Shielded cables,
the minimum bending radius is seven times the armor O.D. - For
Shielded cables, the minimum bending radius is twelve times the
diameter of one phase conductor or seven times the armor O.D.,
whichever is larger.
MAXIMUM PULLING TENSIONS
The following recommendations are based on a study sponsored by the
ICEA. These recommendations may be modified if experience and more
exact information so indicate.
- Maximum Pulling Tension on a
Cable:
- With pulling eye attached to
copper conductors:
WHEN MORE THAN THREE CONDUCTORS
ARE PULLED TOGETHER, THE MAXIMUM PULLING TENSION SHOULD BE
REDUCED BY 20%.
- With cable grip over lead sheath:
- With cable grip over non-leaded
cable:
The maximum pulling tension is determined per grip manufacturer's
specification.
- Maximum Permissible Pulling Length:
- Maximum Tension Requirement in
Ducts:
- For straight duct sections,
the pulling tension equals the length of the duct multiplied
by the weight per foot of cable and the coefficient of friction
(per type of lubricant).
- For curved sections, the following
formula applies:
CABLE SIDEWALL
PRESSURE
The maximum pulling tension
in pounds shall not exceed the following factor times the radius
of curvature of the bend expressed in feet.
| Cable Type |
Factor |
| Low voltage
16 -10 AWG |
300 |
| Low voltage
8AWG & larger |
500 |
| 5KV non-shielded |
500 |
| 5 KV - 35KV
shielded |
500 |
| Interlocked Armor (all) |
300 |
CABLE PREPARATION
AND D.C. HI-POT TESTING PROCEDURE
600 to 5000 Volt Non-shielded
Cables
Common Cable Preparation
(See Diagram A below)
- Remove 18" of the overall
jacket from the end of the cable.
- Clean the insulation with
the proper cable cleaner.
- Remove 1" of the insulation
from the end of the cable.
- Repeat the procedure for
each conductor in the cable.
D.C. High Voltage Test
Note: If the cable to be
tested is a multi-conductor cable, the conductor(s) not under test
must be connected to each other and to the other metallic components
(if applicable). The cable's grounding conductor must be connected
to the metallic components of the cable.
- The D.C. High Voltage
Test is performed by increasing the voltage to the test voltage
and holding the cable at the test voltage for 5 minutes. The leakage
current is then recorded.
- The test voltage is determined
by the conductor size and the type of insulation, and is listed
in Table I, II or III.
Termination
Termination should be made in accordance with the termination kit
manufacturer's procedure.
TABLE I
Thermoset
material, i.e. XLP, EPR, Types XHHW-2, RHH or RHW-2 or USE-2. Testing
is currently for multiple conductors.
| Conductor Size
(AWG or KCMIL) |
DC Test Voltage
(KV)* |
| Cable Voltage
Rating |
| 600V |
1000V |
2000V |
| 14,12,10 |
12.0 |
15.0 |
16.5 |
| 8-2 |
16.5 |
18.0 |
21.0 |
| 1-4/0 |
21.0 |
22.5 |
24.0 |
| 250-500 |
24.0 |
27.0 |
28.5 |
| 600-1000 |
30.0 |
33.0 |
34.5 |
*
- Test Voltage per ICEA.
TABLE II
PVC insulated
conductors
| Conductor Size (AWG or KCMIL) |
DC Test Voltage
(KV)* |
| 14,12,10 |
2.0 |
| 8-2 |
3.5 |
| 1-4/0 |
4.0 |
| 250-500 |
4.5 |
| 600-1000 |
6.0 |
*
- Test Voltage per ICEA.
TABLE III
5000V Non-shielded
MV-90 Cable
| Conductor Size (AWG or KCMIL) |
DC Test Voltage
(KV)* |
| 8-2 |
25.0 |
| 1-4/0 |
25.0 |
| 250-500 |
25.0 |
| 600-1000 |
25.0 |
*
- Test Voltage per ICEA.
Shielded MV-90 (or EPR MV-105)
Cables
Common Cable Preparation
(See Diagram B below)
- Remove 22" of the overall
jacket from the end of the cable.
- Remove the metallic shield
to within 2" of the jacket.
- Remove the semi-conducting
insulation shield layer to within 1" of the metallic shield:
- Score the extruded
semi-con around the cable to within 1" of the metallic shield.
- Score longitudinally
3/8" wide around the cable.
- Grasp the end of the
semi-conducting layer with needle-nose pliers and peel back.
- Clean the insulation with
an appropriate, commercially available cable cleaner.
- Remove 1" of the insulation
and conductor shield from the end of the cable.
- Repeat the procedure for
each conductor in the cable.
D.C. High Voltage Test
Note: If the cable to be
tested is a multi-conductor cable, the conductors(s) not under test
must be connected to each other and to the other metallic components.
The cable's grounding conductor must be connected to the metallic
components of the cable.
- The D.C. High Voltage
Test is performed in steps of 5KV to reach the test voltage. The
leakage current is recorded at each 5KV step. The test voltage
is then held for a period of 15 minutes, and the final leakage
current is then recorded.
- The test voltage is specified
by the voltage and insulation level of the cable. See Table IV
for the appropriate test voltage.
TABLE IV
Shielded MV-90
(or EPR MV-105) Cable
| Voltage & Insulation Level |
DC Test Voltage* |
| 5KV 100% & 133% |
25KV |
| 8KV 100% OR 133% |
35KV |
| 15KV 100% |
55KV |
| 15KV 133% |
65KV |
| 25KV 100% |
80KV |
| 25KV 133% |
100KV |
| 28KV 100% |
85KV |
| 35KV 100% |
100KV |
*
- Test Voltage per ICEA.
Termination
Termination should be made in accordance with the termination kit
manufacturer's procedure.
CABLE END PREPARATION
Diagram A - 600 to 5000
Volt Non-Shielded Cables:
Diagram B - Shielded
MV-90 (or EPR MV-105)Cables:
CABLE
STORAGE PROCEDURE
The cable reel should be securely fastened to a suitable stationary
object to prevent mechanical damage. A tarp or other equivalent
protective covering should be used to protect cable that will be
exposed to weather during storage. Aetna cable is shipped with end
caps, which provide mechanical and moisture protection during shipment.
The end caps on this cable should not be removed till the cable
is tested according to the warranty requirements. Also, if the cable
will not be installed shortly after testing is completed, the end
caps should be replaced to avoid moisture accumulation in the ends
of the cable. Moisture accumulation in the cable can be detrimental
to cable performance, cable life and personnel. Any moisture, which
has accumulated in the cable, should be purged prior to energizing
the cable. For installation below -10°C preheating the wire is recommended
24hrs before installation.
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