Hi Jim, 1. To the best of my knowledge, you would have great difficulties convincing ALL the agencies that any form of varnish impregnation reliably complies with Clause 2.9.7. This is not to say that the concept is invalid; it's just that many agencies are not convinced ...
2. On the other hand, if you have a reliable and consistent varnish coating, there is a better chance that you can convince the agencies to accept Pollution Degree 1 spacings. Of course, this means that you have to prove that the coating is even, and won't shrink or crack after aging. So you're still in for a bit of a battle. In conclusion, all 3 answers you got are technically correct. But for practical purposes, you can save yourself a lot of grief by taking Rich Nute's advice and ignoring the varnish impregnation. BTW, I think Rich's finger slipped on the keyboard. If you need SELV secondary, then the insulation system options he gave you are correct, except for the one that says Basic-core-Basic. This should have read Basic-core-Supplementary. :-) Egon Varju
