Cells values to be check and replace with specific text

I have this date I have 3 Euiprments, I want to make a macro for replace numbers to eduipment name ,where cell contains value 1 till before next cell value =1 will be one equipment no
see in column G
All numbers (number of rows of any equipment will be vary time to time

Srno
1
2
3
12
3
4
5
6
12
3

see the attachment

Sorry see bellow ex.

Srno
[B]1
2
3
[B]1
2
3
4
5
6
[B]1
2
3