UCSB has a limit of 200 credit units (not including credit earned before high school graduation) a student can take, if s/he takes longer than 12 quarters since frosh entry or 6 quarters since junior transfer entry:
https://my.sa.ucsb.edu/catalog/2010-2011/CollegesDepartments/ls-intro/200UnitEnrollmentLimit.aspx
180 is the usual number of credit units that UCSB requires for a bachelor’s degree.