Yes can use same visa only and only if you get a RE ENTRY PERMIT before leaving visa is seperate and work permit is seperate save your NON B first go to immigration or ask HR of your school they know what is this RE ENTRY ok do not let anyone keep your passport .
Megha you can come provided flights operating.Before leaving thailand get a re entry permit multiple not single having multiple entry permit you can come and go till visa is valid.Has your non B visa converted to 1 year visa request submitted or not at immigration secondly if you authorize school to collect work permit on your behalf it will be done DO NOT FORGET RE ENTRY PERMIT BEFORE LEAVING THAILAND OTHERWISE VISA WILL EXPIRE.