CBTM/CBTH – Americas
Medium voltage crosslinked polyolefin bus bar tubing
Medium and heavy wall anti-track heat shrink tubing specifically designed for insulating medium voltage bus bar.
Features and Benefits
- Reduces bus bar clearance requirements
- Protects against accidental flashover
- Sunlight resistant
- Anti-track
- Halogen free
- CBTM medium wall tubing rated to 25 kV
- CBTH heavy wall tubing rated to 36 kV
- 3:1 shrink ratio
- Continuous operating temperature: -40°C to 125°C
- Shrink temperature: 120°C
Standards
- Tested to ANSI C37.20.2 standards for medium voltage switchgear applications to 36 kV
- UL Recognized Component
Typical Applications
Insulation of medium voltage bus bars in switchgear equipment
CBTM Medium Wall Bus Tubing: for services to 25 kV on unbolted bus bar
CBTH Heavy Wall Bus Tubing: for services to 36 kV on unbolted bus bar
*Assume rectangular bus bars have 1/4 in thickness on min application ranges and 5/8 in thickness on max application ranges. Application ranges noted above selected to obtain minimum insulation thickness required to meet ANSI C37.20.2 withstand requirements at bus bar spacing and operating voltages noted. These spacings were determined from a limited number of test configurations. Due to the wide variety of bus bar configurations, these spacings and recovered wall thicknesses should not be employed by the user without actual verification and testing for the intended application. Spacing based on insulation wall thickness per application range of above table.
Market/Applications
- OEM
- Power Distribution
- Industrial
- Power Distribution – MV
- Utility

Ordering
Select a dimension which will shrink snugly over the component to be covered. If recovery is restricted the resultant wall thickness will be less than specified.
- Please specify the product name, order reference number
- Standard is red, printed, unlined, 50 ft lengths (maximum or 1 splice allowed with minimum length of 15 ft)
- Order Example: CBTM, 1300
Please contact your Customer Service Representative for information on custom colors, sizes, lengths and material data sheet.
CBTM Medium Wall Bus Tubing: for services to 25 kV on unbolted bus bar
| ORDER NUMBER | EXPANDED | RECOVERED | APPLICATION RANGES | APPLICATION RANGES | ||||
| INTERNAL DIAMETER (MIN) D | WALL THICKNESS (NOM) W | INTERNAL DIAMETER (MAX) D | TOTAL WALL THICKNESS (NOM) W | *RECTANGULAR BUS BAR | ROUND BUS BAR | |||
| MIN | MAX | MIN | MAX | |||||
| mm (in) | mm (in) | mm (in) | mm (in) | mm (in) | mm (in) | mm (in) | mm (in) | |
| 750 | 19.0 (0.748) | 1.14 (0.045) | 5.5 (0.217) | 2.70 (0.106) | 6.4 (1/4) | 6.4 (1/4) | 6.8 (0.27) | 15.2 (0.60) |
| 1300 | 33.0 (1.299) | 1.14 (0.045) | 10.1 (0.398) | 2.97 (0.117) | 12.7 (1/2) | 28.5 (1 1/8) | 12.4 (0.49) | 27.9 (1.10) |
| 2050 | 52.0 (2.047) | 1.14 (0.045) | 19.0 (0.748) | 2.79 (0.110) | 31.5 (1 1/4) | 50.8 (2) | 22.3 (0.88) | 43.1 (1.70) |
| 2750 | 69.8 (2.748) | 1.14 (0.045) | 25.4 (1.000) | 2.87 (0.115) | 44.4 (1 3/4) | 76.2 (3) | 29.7 (1.17) | 58.4 (2.30) |
| 3500 | 88.9 (3.500) | 1.14 (0.045) | 29.9 (1.177) | 3.09 (0.122) | 57.1 (2 1/4) | 101.6 (4) | 35.8 (1.41) | 73.6 (2.90) |
| 4700 | 119.3 (4.697) | 1.14 (0.045) | 39.9 (1.571) | 3.20 (0.126) | 73.0 (2 7/8) | 142.8 (5 5/8) | 47.7 (1.88) | 101.6 (4.00) |
| 6700 | 170.1 (6.697) | 1.14 (0.045) | 58.4 (2.999) | 3.19 (0.125) | 114.3 (4 1/2) | 203.2 (8) | 69.5 (2.74) | 144.7 (5.70) |
CBTH Heavy Wall Bus Tubing: for services to 36 kV on unbolted bus bar
| ORDER NUMBER | EXPANDED | RECOVERED | APPLICATION RANGES | APPLICATION RANGES | ||||
| INTERNAL DIAMETER (MIN) D | WALL THICKNESS (NOM) W | INTERNAL DIAMETER (MAX) D | TOTAL WALL THICKNESS (NOM) W | *RECTANGULAR BUS BAR | ROUND BUS BAR | |||
| MIN | MAX | MIN | MAX | |||||
| mm (in) | mm (in) | mm (in) | mm (in) | mm (in) | mm (in) | mm (in) | mm (in) | |
| 1100 | 27.9 (1.10) | 1.67 (0.066) | 8.9 (0.35) | 3.88 (0.153) | 9.5 (3/8) | 12.7 (1/2) | 10.6 (0.42) | 17.7 (0.70) |
| 2000 | 50.8 (2.00) | 1.57 (0.062) | 16.0 (0.63) | 4.08 (0.161) | 22.2 (7/8) | 34.9 (1 3/8) | 19.3 (0.76) | 33.0 (1.30) |
| 2700 | 68.0 (2.68) | 1.52 (0.060) | 22.1 (0.87) | 4.08 (0.161) | 34.9 (1 3/8) | 50.8 (2) | 26.1 (1.05) | 43.1 (1.70) |
| 3500 | 89.9 (3.54) | 1.52 (0.060) | 29.9 (1.18) | 4.08 (0.161) | 50.8 (2) | 76.2 (3) | 35.8 (1.41) | 58.4 (2.30) |
| 4700 | 119.9 (4.72) | 1.57 (0.062) | 39.9 (1.57) | 4.19 (0.165) | 69.8 (2 3/4) | 111.1 (4 3/8) | 47.7 (1.88) | 81.2 (3.20) |
| 6600 | 167.6 (6.60) | 1.67 (0.066) | 65.0 (2.56) | 4.19 (0.165) | 114.3 (4 1/2) | 177.8 (6 1/2) | 69.5 (2.74) | 124.4 (4.90) |
*Assume rectangular bus bars have 1/4 in thickness on min application ranges and 5/8 in thickness on max application ranges.
Clearances with Insulation
| System Voltage | BIL KV | CBTM Medium Wall Tubing | CBTH Heavy Wall Tubing | ||
| P to P | P to G | P to P | P to G | ||
| mm (in) | mm (in) | mm (in) | mm (in) | ||
| 15 kV | 95.0 | 86.0 (3.386) | 106.0 (4.173) | 55.0 (2.2) | 66.0 (2.6) |
| 25 kV | 125.0 | 114.0 (4.488) | 152.0 (5.984) | 71.0 (2.8) | 101.0 (4.0) |
| 36 kV | 150.0 | 165.0 (6.496) | 203.0 (7.992) | 142.0 (5.6) | 190.0 (7.5) |
P to P: Phase to Phase orientation
P to G: Phase to Ground orientation
Spacing based on metal to metal dimension prior to insulation. Spacing based on insulation wall thickness per application range of above table.


