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Cold Shrink EPDM Tubes

Connector Insulators 8420 Series

Data Sheet

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Electrical Markets Division

3M United Kingdom PLC

3M Ireland Ltd

3M United Kingdom PLC

Sales Office

Sales Office

Head Office

PO Box 393

The Iveagh Building, The Park,

3M Centre, Cain Road

Bedford MK41 0YE

Carrickmines, Dublin 18, Ireland

Bracknell, Berkshire RG12 8HT

Telephone: 0870 609 4639

Telephone: (01) 800 812 732

Telephone: 01344 858 000

Fax: 01234 229 433

Fax: 353 1 280 3509

Fax: 01344 858 758

instructions provided with 3M Brand PST Cold Shrink Connector Insulators.

Engineering/Architectural

The connector insulator must be capable of operation at emergency overload cable temperatures of 130°C. It must be

usable without additional covering or adhesive, both indoors and outdoors, in overhead, direct buried or submersed

applications, on cables rated up to 1000 volts. It must be applied without additional heat or flame and, when applied

according to the manufacturer’s directions, but immediately energizable. It must not be adversely affected by moisture,

mild acids or alkalis, ozone or ultraviolet light. It must be compatible with all rubber or plastic insulated 1000 volt cables.

It must conform to the requirements of ANSI C119.1 1974, appropriate sections of Western Underground Guide 2.14 and

UL 486D. It must have been accepted by the US Dept of Agriculture, Rural Electrification Administration, for both

submersible and aerial application.

Performance Tests

The characteristic which is vital to the performance of the PST is permanent set. Permanent set is defined as “the

percentage of the original stretched deformation not recovered in a given period of time after the deforming force (core)

has been removed”. Because the PST tube has not been allowed to return to its original ID by the cable, a live rubber

force exists between the cable insulation and the PST tube.

The 8420 series tubes are installed on the core at approximately 250% stretch. The permanent set test is done in the

tension mode and reflects the elastic memory property of the material. Field experience combined with laboratory test data

has shown that our EPDM PST/Cold Shrink™ compounds exhibit excellent long-term elastic memory characteristics.

Moisture, Heat and Seal Tests

3M Brand Connector Insulators meet or exceed the test requirements of UL486D and ANSI C119.1.

Test Sequence.

1.

24 hours in room temperature water (30cm deep).

2.

Insulation resistance at dc (500 to 1000V), 1 minute.

3.

Dielectric ac withstand, 1 minute at 2200V.

4.

Heat at 90°C (

±5°C) for 72 hours.

5.

Flex test: 10 cycles for 90° right and 90° left.

6.

Twist test: twist 15° clockwise and then 15° counter-clockwise from centre 5 times.

7.

Water immersion as in Step 1.

8.

Insulation resistance as in Step 2.

9.

Cold temp. 4 hours at –18°C

± 5°C. Bend and twist per Steps 5. and 6. at temp.

10. Flex per Step 5.

11. Twist per Step 6.

12. Water immersion as in Step 1.

13. Insulation resistance as in Step 2.

14. Current cycle and water submersion test:

a) Heat conductor with current to 90°C for 1 hour.

b) De-energize.

c) Plunge in 25°C (

± 5°C) water within 3 minutes of Step b) for ½ hour minimum.

d) Repeat Steps a), b) and c), 25 times.

e) Measure insulation resistance per Step 2.

f) Repeat Steps a), b) and c), 25 times.

g) Dielectric test as in Step 3.

15. Dielectric withstand as in Step 3.

16. Leakage current in water 600V 60hz. 2.5mA max. leakage.

PSTs will seal within 5 minutes at –1°C even on the absolute minimum cable size. Thus, warming with the hands is not

necessary, even below freezing.