The UPS uses the Preheat cycle in order to warm the rotor. Verify if preheat is necessary before the start of the flywheel. There are various factors that determine if preheating is required. The first factor is the armature temperature.
The armature temperature of the flywheel must be at least
- when you enter the "On-line" state.
- prior to the calibration of the Rotor Position Sensor
If the temperature is greater than
In a normal preheat cycle, the armature temperature determines the length of the preheat cycle. If the temperature is below
After preheat is completed, a time period of thermal equalization is needed. The time allows the heat that is generated in the armature to be radiated into the rotor. Thermal equalization allows temperatures to equalize. The minimum and maximum times for equalization are 6 minutes and 15 minutes. The time for the equalization of the temperatures will be equal to the preheat time. The time period for thermal equalization will not be greater than 15 minutes.
Once the preheat cycle is complete, the UPS will automatically continue with start-up or the calibration of the Rotor Position Sensor.
A 42 minute preheat cycle will be initiated if the power to the flywheel cabinets has been turned off for more than 48 hours. In some applications, the preheat cycle will not be needed. If the preheat cycle is not needed, if completed, the length of the preheat cycle will overheat the armature. This overheating will result in a delay in order to obtain nominal rotor speed. Call technical support in order to receive a password for bypassing the 42 minute preheat mode.
The technical support representative will ask three questions in order to determine if the preheat time can be shortened. The following statements will pertain to the questions that will be asked by the representative:
- the temperature in the room of the flywheel
- the length of time of the flywheel in the room in this temperature
- the length of time since the energizing of the flywheel (full speed)
If a certain condition exists, technical support will issue a special password in order to override the timing for preheat. You must have a computer that is connected via a direct serial connection. Use the keystroke "Ctrl-^" in order to issue the command into the UPS.