Yes 1 is wrong. 2 also has problems. There needs to be a space before "At", and a space after "in". Other than that, 2 is OK.
Student or Learner
1. At no time you are to work alone on a machine inthe lab.
2.At no time are you to work alone on a machine inthe lab.
Is #1 wrong? Is it necessary to change the word order like #2 when "at no time" is placed at the beginning of a sentence?
You will find subject/verb inversion in many English contexts.
At no time are you to work alone.
You are not to work alone at any time.
Never again will he see her beautiful face.
He will never see her beautiful face again.
Only once did she speak his name.
She spoke his name only once.
'Under no circumstances should you work alone on a machine in the lab.'
I think inversion is intended to add emphasis, but I am not a teacher.
Most of the adverbial structures that cause this inversion are (near-) negatives: at no time, hardly (=almost not), little (= not much), never, not until later, not only, seldom (= almost never).
Phrases with only often have negative undertones:
only after - not until after
only then - not until then
only once - no more than once