Your Collective Bargaining Agreement provides that you cannot be required to work more than 220 hours per quarter for a 50% FTE appointment. Hours for different percentage appointments are prorated. Summer Quarter workload for 50% ASEs working 4 pay periods is 176 hours.
You can download a grid here that enables you to estimate and track your hours. If you have any concerns that you might exceed your contractual workload, contact your union representative immediately to discuss next steps.