Initial Test Results and Test Plan for Differential Temperature Controllers Used in Solar Energy Systems

摘要

The initial test results and procedures used to conduct tests on differential temperature controllers used in solar energy systems are discussed. These tests were performed on generally non-adjustable, non-display units and include the following functional tests conducted at ambient conditions: delta T 'on' and 'off'; recirculating freeze protection with and without auxiliary sensor; controller response to sensor sensitivity; storage high temperature limit; and pump 'off' below 80 C. Controller sensitivity to line voltage variation tests were also conducted at ambient conditions and include: delta T 'on' and 'off' and recirculating freeze protection. The controller test fixture is also described along with the recommended use of decade resistance boxes to simulate thermistor inputs. An overall test plan is also included as an appendix to the report.