First of all I welcome you in this discussion board.
LTC is allowed only once in the whole service life and it can be availed during the period of 5 years before retirement.
So, as a newly joined employee, you'll not get the facility of LTC from the department. However, this rule is applicable for State Govt. Employees only.
I don't know the rules regarding this in case of an employee of Power Development Corporation Limited.
If it is assumed that PDCL allow the benefit to your spouse now, and you both avail the facility as a family unit, then you should inform it to your department and you will not be entitled for LTC further from your department. A declaration in this regard is to be submitted to the Controlling Authority, so that it is recorded in your service book.
Consult the following G.O.s for a complete understanding of LTC.
G.O. No. 9924-F dated 07.12.2005
G.O. No. 607-F dated 20.01.2006
G.O. No. 4367-F dated 13.06.2006.
No further G.O. published in this regard.
Don't hesitate to ask any query. I hope you will be an active member of this forum. Thank you for joining this forum.