I'm currently proof-reading my girlfriend's Ph.D. thesis (neither of us are native speakers) and I came across the following sentence snippet: "the switching-off induces eddy currents", and the word 'switching-off' struck me as odd.
I think it should be written without a hyphen; my reasoning is vague, but seems to hinge on the distinction I feel there is between 'the turning on' (i.e. 'the activating') and 'the turning-on' ('the causing of arousal').
A quick search in my Concise Oxford Dictionary hasn't given me any ideas, so my question is: What's the correct way of writing the gerund of compound verbs?
Any online resources going into this would also be much appreciated!