Q & A of the Day – PVC cable in conduit when passing through polyurethane insulation?

BookmarkThis 22.01.2008
BASEC (The British Approvals Service for Cables)
 

Our Voltimum Experts answer your questions on a daily basis in our Technical Expertise area. This Question of the Day, about whether PVC cable should be contained in conduit if passed through polyurethane insulation, is answered by BASEC:

PVC sheathed cable need not be in conduit.
PVC sheathed cable need not be in conduit.
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Question: Does PVC cable require to be inside conduit if passing through polyurethane insulation?

If PVC cable passes through expanded polysytrene insulation, it requires to be in conduit to prevent migration of the plasticiser from the cable to the polystyrene. Is the same true if it is in contact with polyurethane of polyiso (rigid polyisocyanurate)?

Answer: Only polystyrene thermal insulation is of serious concern for PVC sheathed cables. In general it is not required to place PVC sheathed cables in separate conduit if passed through polyurethane or polyisocyanurate thermal insulation. The thermal insulation polymers are different and do not have residual chemicals present that are found in polystyrene thermal insulation.

Thermal insulation manufacturers have confirmed this position with BASEC.

To see many more Q & A in Voltimum UK's Experts Area, please click on the link:

http://www.voltimum.co.uk/consult.php?universe=consult.index.questions

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The British Approvals Service for Cables (BASEC)
23 Presley Way, Crownhill,
Milton Keynes MK8 0ES
Tel: 01908 267300
Fax: 01908 267255
Email: mail@basec.org.uk
Web: www.basec.org.uk
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Source: BASEC & James Hunt

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