16. Bakeout in function
16.1 What is heater bakeout?
If a MgO-insulated heater element shuts down for a long period of time (or sits in storage), it can absorb moisture. If
full power is applied, excessive current can damage the heater or blow fuses.
The heater bakeout feature soft starts the load to remove moisture from the heater and prevent blown heaters and
fuses.
16.2 How does heater bakeout work?
During heater bakeout, the Power Unit slowly increases voltage to the heater while monitoring the output current:
• If the heater achieves full output before the bakeout time expires, then the heater is dry and can be put into service.
• If the output current reaches a user-specified trip point during the bakeout - as it would if arcing occurred in the
heater - then the Power Unit shuts off the output and activates an alarm.
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