GE CTR 80 User Manual

policies regarding flash points, toxicity, and such issues must be considered.You are responsible for reading the (material safety data sheets) and actingaccordingly.8.2 StirringStirring of the bath fluid is very important for stable temperature control. Thefluid must be mixed well for good temperature uniformity and fast controllerresponse. The stirrer is precisely adjusted for optimum performance.8.3 PowerPower to the bath is provided by an AC mains supply. See Section 3.1, Specifi-cations, for power details. Refer to and read the CAUTION at the front of thismanual concerning brownout and over voltage protection. Power to the bathpasses through a filter to prevent switching spikes from being transmitted toother equipment.To turn on the bath switch the control panel power switch to the ON position.The stirring motor will turn on, the LED display will begin to show the bathtemperature, and the heater will turn on or off until the bath temperaturereaches the programmed set-point. When powered on the control panel displaywill briefly show a four digit number. This number indicates the number oftimes power has been applied to the bath. Also briefly displayed is data whichindicates the controller hardware configuration. This data is used in some cir-cumstances for diagnostic purposes.8.4 HeaterThe power to the bath heater is precisely controlled by the temperature control-ler to maintain a constant bath temperature. Power is controlled by periodicallyswitching the heater on for a certain amount of time using a solid-state relay.The front panel LED heater mode shows the state of the heater. The indicatorglows red when the heater is on and is off when the heater is off. The indicatorwill pulse constantly when the bath is maintaining a stable temperature.8.5 RefrigerationThis bath uses a two-stage refrigeration system which requires special refriger-ants to enable it to reach low temperatures. This section describes some aspectsof the cooling system and provides important information regardingrefrigerants.328 General Operation