If a man has intercourse with his wife during the day in Ramadaan whilst traveling, there is nothing wrong with that
Question

                What is the ruling on a man who has intercourse with his wife during the day in Ramadaan whilst traveling?.
Praise be to Allah.
    He does not have to offer expiation and there is no sin on 
    him, because the traveler is permitted not to fast, but he has to make up 
    that day. 

    The Standing Committee (10/202) was asked about the ruling on 
    a man who has intercourse with his wife during the day in Ramadaan when they 
    are traveling and not fasting. They replied: 

    It is permitted for a traveler who is traveling during the 
    day in Ramadaan to break the fast, because Allaah says (interpretation of 
    the meaning): 
“and whoever is ill or on 
    a journey, the same number [of days which one did not observe Sawm (fasts) 
    must be made up] from other days”

    [al-Baqarah 2:185]

    It is permissible for him to eat, drink and have intercourse 
    so long as he is traveling. 

    Shaykh Ibn Baaz was asked in Majmoo’ al-Fataawa 
    (15/307) about the ruling on a man who has intercourse during the day in 
    Ramadaan when he is fasting; is it permissible for a traveler to have 
    intercourse with his wife if he is not fasting? 

    They replied: 

    The one who has intercourse during the day in Ramadaan when 
    he is observing an obligatory fast has to offer expiation, i.e., the 
    expiation of zihaar (which is to free a slave; if that is not 
    possible then to fast for two consecutive months; if that is not possible 
    then to feed sixty poor persons). He must also make up that day, and repent 
    to Allaah for what he has done. But if he is traveling or sick, it is 
    permissible for him not to fast, and he does not have to offer any 
    expiation, and there is no sin on him, but he has to make up the day on 
    which he had intercourse, because those who are sick or traveling are 
    permitted not to fast and to have intercourse etc, as Allaah says 
    (interpretation of the meaning): 
“and whoever is ill or on 
    a journey, the same number [of days which one did not observe Sawm (fasts) 
    must be made up] from other days”

    [al-Baqarah 2:185]
The ruling on a woman in 
    this case is the same as that on a man, if it was an obligatory fast then 
    she has to offer expiation and make up that day; if she was traveling or was 
    sick and fasting would be too difficult, then she does not have to offer 
    expiation. 

    Shaykh Ibn ‘Uthaymeen was asked in Fataawa al-Siyaam 
    (344) about a man who had intercourse with his wife during the day in 
    Ramadan when he was traveling. 
He replied: There 
    is no sin on him for that, because the traveler is permitted to break his 
    fast and to eat, drink and have intercourse, so there is no sin on him and 
    he does not have to offer expiation. But he has to fast another day to make 
    up the day that he did not fast in Ramadaan. Similarly there is no sin on 
    the woman if she was travelling and not fasting on that day. But if she was 
    not traveling then it is not permissible for him to have intercourse with 
    her if she is observing an obligatory fast, because he will invalidate her 
    acts of worship, so she has to refuse.