ITC on Capital goods

we can ITC 100%

you can avail full ITC

Yes you can take ITC when used for business purpose. 
As per Section 2(19) of the Central Goods and Services Tax (CGST) Act, 2017, unless the context otherwise requires, the term 'capital goods' means goods, the value of which is capitalized in the books of accounts of the person claiming the input tax credit and which are used or intended to be used in the course or furtherance of business.

For taking ITC., following should also be satisfied 

1. Gst registration should be regular type 
2. Invoice bill should bears the company name & Gstin
3. Gst  bill should be of B2B

Yes you can claim full ITC at the time of purchase of generator... But if you sold that capital asset before the expiry of 5 years The ITC Shall be reverse to the Department On the basis of Turnover.