nVent Terminating Single Conductor Copper Sheathed Mineral Insulated Cable User Guide

Terminating Single Conductor Copper Sheathed Mineral Insulated Cable

QuickTerm Termination Kit

Installation Instructions for Terminating Single Conductor Copper
Sheathed Mineral Insulated Cable

DESCRIPTION

This nVent PYROTENAX QuickTerm termination kit is used to terminate #6 AWG and larger single conductor nVent PYROTENAX Mineral Insulated (MI) cables. A special tape is provided to seal the end of the MI cable and a compression connector is used to join the MI cable solid conductor to an equivalent size flexible stranded conductor tail (supplied by installer).

For technical support, contact your local nVent representative or Customer Care at 800-545-6258.

TOOLS REQUIRED

• nVent PYROTENAX Power Stripper Tool (PSTKIT) for cables up to
  0.543 in (1.38 cm) diameter or nVent PYROTENAX Sheath master
  Sheath Stripping Tool (GL) for cables up to 3/4 in (1.9 cm)
  diameter or nVent PYROTENAX Ratchet Type Stripping Tool
  (RSTRIPKIT) for cables larger than 3/4 in (1.9 cm) diameter

• nVent PYROTENAX Hand vise

• Hacksaw

• Flat file

• Scribe or pick

• Permanent marking pen

• Clean dry cloth or rag

• Tape measure or ruler

• Hydraulic crimping tool (see Table 2)

• 500 Vdc megohmmeter

• Electric heat gun (recommended) or propane torch

• Safety goggles and gloves

• Oxy-acetylene or MAPP gas torch (to dry out cable)

• Diagonal (side) cutter and tube cutter (if stripping cable sheath as
  shown in Appendix B)

MATERIALS REQUIRED

• 90°C, 600 V insulated stranded copper conductor tails (RW90, THHN or equivalent – see Table 2 on page 3 for conductor size required) of appropriate length and same
size as the MI solid conductor

APPROVALS

Nonhazardous Locations

KIT CONTENTS

The QuickTerm kit contains sufficient material to terminate both
ends of a cable.

Item Qty Description
A 2 Heat-shrinkable tubing
B 2 Brass gland connectors
C 2 Copper compression connectors
D 1 or 2* Self-amalgamating tape (roll)
E 1 Emery paper (roll)

• Number of rolls depends on the termination kit

WARNING:

This component is an electrical device that must
be installed correctly to ensure proper operation
and to prevent shock or fire. Read these important
warnings carefully and follow all installation
instructions

• When MI cable is stripped and terminated, cut
metal edges can cause cuts and loose powder
can cause eye irritation. To prevent injury, gloves
and safety glasses must be worn when carrying
out these operations.

• To prevent burns when drying out the cable
(Appendix C), allow it to cool until warm to
the touch before completing the remaining
termination instructions.

1 Note: The minimum installation temperature for this QuickTerm termination kit is 32°F (0°C).
• With a hacksaw, cut the end of the MI cable square and file the end smooth.
• Identify the compression connector supplied with the termination kit. Locate the corresponding compression connector part number in Table 2 on page 3 and mark the MI cable sheath at length “L” shown. This is the length of sheath to remove.

• Place a second mark “T” behind this first mark per Table 1 below depending upon which stripping tool is used.
• The sheath will only be stripped back to the first mark exposing the solid conductor. The second mark from the end is used to position the Handvise for final stripping.
• For details on using the Sheathmaster Stripping Tool, refer to instruction H59039 supplied with the tool. For the Ratchet Type Stripping Tool, refer to instruction H57842 supplied with the tool. For the Power Stripper Tool, refer to instruction H61464 supplied with the tool. An alternate method of stripping the cable sheath using a tubing cutter and side cutters is shown in Appendix B.

Table 1
Tool Type T (Stripping Tool Required Length)
Sheathmaster Stripping Tool 1″ (2.5 cm)
Ratchet Type Stripping Tool 1.5″ (3.8 cm)
Power Stripper Tool 5″ (12.7 cm)

2 • Place the brass gland connector on to the cable. The gland connector is made up of three parts: the gland nut, the compression sleeve and the gland body. It should be placed on to the cable with all three pieces assembled.

3

• Grip the cable with the Handvise.
• Using the sheath stripping tool (Ratchet Type Stripping
Tool shown), begin stripping the copper sheath back towards the first mark.

5

• Clean the conductor with a clean, dry, rag or cloth to
remove loose powder from the conductor. Next,
polish all around entire length of solid conductor and
2 in (5.0 cm) of sheath behind the conductor with emery
paper to achieve a clean surface.
• Visually inspect the magnesium oxide insulation at the
face of the cable for traces of copper filings and burrs
and if present, gently remove with a pick.

Note: When cleaning the conductor with the rag and
emery paper and if it is necessary to use a pick to remove
copper filings from the face of the cable, do not remove
more powder from the face of the cable than is necessary.

Note: Do not blow out copper filings that may be present
in the magnesium oxide (MgO) powder as this can introduce
moisture into the end of the cable, resulting in decreased
insulation resistance.

6

• Using a 500 Vdc megohmmeter, check the insulation resistance (IR) of the cable between conductor and sheath to ensure it is free of grounds and shorts. The other cable end must also be free of grounds and shorts and must be sealed. See Appendix A for detailed test procedure and IR test criteria. Once IR readings are satisfactory, immediately complete Step 7 to seal the end of the MI cable. A delay will cause the IR to drop and the cable must be retested prior to sealing the end.

Note: If neither cable end has yet been terminated and IR readings are low, dry out both ends following the procedure in Appendix C or cut off shorted end and retest. Apply a temporary moisture resistant seal, such as hot melt glue or adhesive lined heat-shrinkable tubing, to opposite cable end to prevent moisture absorption.

7

• Apply tape seal to MI cable and ensure that you tape along the sheath and solid conductor as shown. Stretch the sealing tape to about 3 times its length (or about half of the original width), just short of the breaking point.
• Beginning on the cable sheath and using half-laps, wind the tape under tension, taping 1-1/2 in to 1-3/4 in (3.8 cm to 4.5 cm) along the cable sheath and 1-1/2 in to 1-3/4 in (3.8 cm to 4.5 cm) along the solid conductor.
• Reverse the direction and wind the tape back along the conductor and 1-1/2 in to 1-3/4 in (3.8 cm to 4.5 cm) of cable sheath (over the tape just applied).

• Finally, reverse the direction once again and wind the tape back along the sheath and 1-1/2 in to 1-3/4 in (3.8 cm to 4.5 cm) of conductor (again, over the tape just applied). Maintain half-laps and stretch tape as described above while winding along sheath and conductor. Tear off excess tape. The tape will bond to itself in a short time. Important: Use only the self-amalgamating tape supplied by nVent to seal the end of the MI cable.

8

• Once the tape seal is completed to this point, the end of
the MI cable should appear as shown.

9

• Strip just enough insulation from the 90°C, 600 V stranded
conductor tail to fit to the center-stop in the compression
connector (see Table 2 for further details on the size of
stranded conductor tail required).
• Crimp the connector to the stranded conductor tail using
the required number of crimps and an approved crimping
tool (see Table 2 on page 3 for details). Where multiple
crimps are required, make the outside crimp first and
work towards the middle of the connector.
Important: See Table 2 on page 3 for approved crimping
tools to be used with the QuickTerm compression connectors.

10

• Place the adhesive lined heat shrinkable tubing (supplied
with termination kit) on to the MI cable.
• Insert the solid MI conductor into the other end of the
compression connector.
• Crimp the connector to the solid conductor using the
required number of crimps and an approved crimping tool
(see Table 2 on page 3 for details). Where multiple crimps
are required, make the outside crimp first and work
towards the middle of the connector. The solid conductor
to stranded conductor joint should appear as shown.

11

• Prior to sealing the entire joint with the heat-shrinkable
tubing, remove all sharp edges from the compression
connector with a flat file.
• Place the heat-shrinkable tubing over the joint so that
it completely covers the tape seal and compression
connector and overlaps the MI cable sheath and the
insulation on the stranded conductor tail by at least
1/2 in (1.3 cm).
• Shrink in place with a heat gun or propane torch being
careful not to damage the heat-shrinkable tubing.
When using a propane torch, take care not to burn the
heat-shrinkable tubing.

12

• Check IR once more from stranded conductor tail to MI
cable sheath to ensure that the cable has been properly
sealed and IR is satisfactory. If the IR does not meet the
values under Test Criteria in Appendix A, the termination
must be removed and remade after completing the
“drying out” procedure outlined in Appendix C.

Appendix A: Insulation Resistance (IR) Test

Test Equipment
500 Vdc Megohmmeter

IR Testing
IR testing is conducted using a megohmmeter and tests the
integrity of the cable between the conductor and the copper
sheath.

Test Criteria
When received:
• Check cable on reel. Note that ends may need to be
prepared to allow insulation resistance (IR) readings to be
taken. IR readings must not be less than 200 MΩ under any
conditions.

After installing termination kit:
• In a warm, dry environment, IR readings should be 200 MΩ
or higher.
• In an outdoor environment or indoors in wet or humid
conditions, IR readings should all be above 100 MΩ.
• Similar cables exposed to similar conditions should all
have IR readings in the same general range. Where a large
difference in readings is encountered, high readings can be
accepted; low readings (below 100 MΩ) should be checked
as described below.

Note: Under some installation conditions it may not be
possible to obtain IR readings above 100 MΩ. If IR readings
are between 25 MΩ and 100 MΩ, wait 24 hours and recheck
the IR using the same equipment. If the IR reading has not
decreased, the termination is good – a constant low IR reading
can result from moisture entrained in the cable while making a
good seal; this moisture will not increase. If the IR reading has
decreased, the cable must be re-terminated – a low IR reading
can result from a poorly made seal which will allow continuing
moisture ingress, requiring that the termination be redone.
If the IR reading is less than 25 MΩ, the cable must be
re-terminated following the “drying out” procedure in
Appendix C.

Test Procedure

1. Set megohmmeter test voltage at 0 Vdc or off.
2. Connect the positive (+) (earth) lead to the cable sheath.
3. Connect the negative (–) (line) lead to the conductor.
4. Turn on the megohmmeter and set the voltage to 500 Vdc;
apply the voltage for one minute. Meter needle should stop
moving. Rapid deflection indicates a short. Note the insulation
resistance value. It should correspond to the values shown
under Test Criteria.
5. Turn off the megohmmeter.
WARNING: Shock Hazard. The MI cable can store a
large electrical charge after the insulation resistance
test is performed. To prevent personal injury from electrical
shock, fully discharge the cable prior to disconnecting
the megohmmeter. Many meters will discharge
automatically. However, it may be necessary to short the
cable leads. Contact your supervisor or the instrument
manufacturer to verify the safest practice.
6. Testing is complete. If the megohmmeter does not selfdischarge,
discharge phase connection to ground with a
suitable grounding rod. Disconnect the megohmmeter.

Appendix B: Stripping MI Cable Using Side Cutters

Using diagonal cutters
Measure, from cable end, length of cable sheath to strip and
mark sheath with marking pen. Use a tube cutter to score
around the sheath at the mark. This will cause the sheath
to peel away at the score providing a smooth end when the
sheath is stripped. The correct depth of score is half the
thickness of the sheath.
Do not cut completely through the cable sheath as this will
cause the sheath to curve inwards toward the conductor(s).

Hold the cable with the handvise behind the score on the
sheath. Grip the edge of the sheath between the jaws of the
side cutters and twist clockwise (twist counter-clockwise if
lefthanded), then take a new grip and rotate through a small
angle.

Continue this motion in a series of short “rips”, keeping the
side cutters at about 45° to the line of the cable, removing
sheath spirally. Remove compacted powder insulation to
expose conductors.

Continue removing the sheath to the score mark. When about
to break into the score, bring side cutters to right angle with
cable. Finish off with point of side cutters held parallel to the
cable. The sheath will peel away leaving a clean cut when the
score mark is reached.

The cable sheath is correctly stripped, with the sheath flared
slightly outwards, as shown in (a).
In (b) the sheath is neither flared outwards nor beveled
inwards, but is acceptable.
Ensure that the sheath is not curved or beveled inward as
shown in (c). This will occur if the score made with the tube
cutter is too deep. In this case, remove a further 1/4 in (6
mm) of sheath. Cable is now ready to be sealed.

Appendix C: Improving Insulation Resistance

To maintain the high performance of MI cable, the cable must be properly stored and the ends must remain sealed.
Damaged terminations or heat-shrinkable end caps that are damaged, missing, or removed will cause the magnesium oxide insulation (white powder) to absorb moisture, resulting in low IR readings. The cable must be “heated out” to remove the moisture and bring the IR back to an acceptable level. Drying out the MI cable to remove any moisture will normally be unnecessary providing the termination seal is completed within a few minutes of removing the sheath.

If moisture is found in the cable when checking IR, it may be removed using one of the following methods:
1. If excess cable is available, 6 to 12 in (15 to 30 cm)
of cable may be removed from the end before sealing
the cable.
2. Apply heat to the cable following the procedure below.

Note: Moisture will not normally penetrate more than
12 in (30 cm) into the cable.
If moisture is detected in the cable, use an oxy-acetylene or MAPP gas torch with a large flame and “heat out” the cable beginning 12 in (30 cm) back from the end. Gradually move the flame toward and past the cable end. Copper sheathed cables should be heated to a bluish-gray color. Take care not to overheat any one area of the cable sheath as this could damage the cable.
Use a short sweeping motion of the torch and heat about 2 in (5 cm) of cable at a time, repeating 4 to 5 times.
Move the flame towards the cable end as shown. Do not sweep the flame in the opposite direction as this will drive the moisture into the cable.

Gradually move the flame toward the end while maintaining the short sweeping motion of the torch. If you heat toward the cable end too quickly you may skip over the moisture and drive it further back into the cable.

It may be necessary to repeat the above procedure several times to completely remove all moisture from the cable. Allow the cable to cool before repeating. On completion, check IR with a 500-V insulation tester (Megohmmeter).

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