This article is not intended to provide professional consultation or service. It contains my technical opinion and is for general information purposes only.

Electrical designers are accustomed to using 1KV cables like Teck90 for their low voltage applications. Often there is confusion on if it is safe to use 600V rated cables in 600V or lower electrical systems. The short answer is, yes. The 600V RW90 conductors used in our common CSA cables, such as AC90, ACWU90, RA90, and Teck90, are designed to meet the requirements of 600V systems. This includes both ungrounded and resistance grounded systems.

The question arises when designers evaluate using wiring methods other than 1KV Teck90 cables. ACWU90 cables with aluminum conductors and RW90 installed in conduits are common 600V rated alternates to 1KV copper Teck90. Confusion over using these 600V products led Electro Federation Canada to issue an electrical industry communique back in 1996.

Electro Federation Canada clarified that the insulation thicknesses of the RW90 conductors used in these products are designed for mechanical wear and tear, with more than sufficient insulation for electrical stress containment. CSA standard C22.2 #38 determines the insulation specification of RW90 conductors, ensuring the insulation will be thick enough to accommodate the wear and gouging incurred when pulled through long runs of conduit. ACWU, AC90, and Teck90 are armored cables that use the C22.2 #38 RW90 insulation thicknesses for their conductors. Inside these armored cable constructions, there should be none, or very little mechanical wear of the conductors, yielding electrically overbuilt products.

A STANDATA electrical safety information bulletin was issued in Feb 2019 referencing this paper. It stated 600V RW90 rated cable is suitable for use on 600V ungrounded and impedance grounded systems.

Go ahead and design systems using 600V products like ACWU or RW90 into your 600V electrical systems and enjoy the cost savings they might offer.