Regulation s. 186 (f) does not specify the number of hours per week.  Thus, the student can work "as many hours" on campus as needed provided the student is a full time student as defined by the educational institution and is studying in an academic, professional or vocational program. 
 

Exclusion:

 the student who is studying English or French as a second language is not allowed to work on-campus or off-campus.   
 

EXCEPTION:

  if the student is a studying full-time academic program and also studying English as part of it, the student can work on or off-campus as per Program Delivery Instructions (PDI) exemption.
 

NOTE:

  The study permit must have to have a remark "May be eligible to work on or off campus if meets R 186 (f) or (v) or (u).

Typically:  The students who are studying English or French as a second language would not have the remark to work on or off-campus.

• Reference 1
• Reference 2

You can get an Open Work permit if you:

• have a spouse who holds a Work Permit with at least 6 months and works in HIGH SKILLED positions in such NOCs as Noc 0, Noc A or Noc B
• have a spouse or common-law partner who has a Study Permit in academic or vocational or professional programs in public Colleges or Universities or in Private institutions that confer a degree (Associate or Bachelor's or Master's degree).  Or student in CEGEP in Quebec. NOTE: Diplomas or Certificates from Private Institutions do not allow to get OWP.
• Have a spouse who applied for Bridging Open Work Permit under Express Entry or PNP nomination
• you are sponsored under Spouse or Common-Law partner in Canada class

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