I suggested that division without examining the details.
Your variable declaration of Volt_Alarm_Set_Point as an integer could be changed to a float.
The C programming language takes integer math literally in this case and returns an integer since both the operands are integer.
Volt_Alarm_Set_Point / 10 returns an integer (they are both integers).
Multiplying by 0.1 (a literal float data type) will produce a float result.