4.11.3 Soft Start Timer

P41 = SS.

A Soft Start timer starts automatically on power up. It applies a power limit (‘SS.oP’ set in Level 2) until the temperature reaches a value (‘SS.SP’ set in Level 2). It is typically used, for example, to dry-out heaters in Hot Runner control systems before full power is allowed.

 

 

Example: To Configure and Set up a Soft Start Timer

  1. In Conf level set P41 = ss to select Soft Start type timer

  2. In Conf level set P42 = HoUr or Nin to select the timer resolution. In this example Nin

    (Note: ‘P’ code P43 is not shown when this timer type is configured).

  3. In Level 2, set the Timer Duration parameter t.dUr to the required period. In this example 1 minute.

    (Note: t.tHr is not shown when this timer type is configured).

  4. In Level 2, set SS.SP to the required soft start setpoint threshold. In this example 50OC.

  5. In Level 2, set SS.oP to the required power limit. In this example 20%.

  6. In level 1 or 2 set SP1 to the required operating level. 100OC in this example.

  7. In level 1 or 2 set the Timer Status parameter t.St to run or power cycle the controller. The display will flash between rUn and the current setpoint. The time elapsed parameter t.EL will begin to count up and the time remaining t.rE parameter will begin to count down.

    During the timing period the control outputs (heat and cool) will be limited to SS.oP (20.0%).

    At the end of the timing period the display will flash between End and the current setpoint. The control outputs will go to the required demand level.

    At this point entering a further time in the parameter t.rE will switch the controller back to run again for the additional time, the outputs will go to ss.op and will switch back to control at the end of the timing period.

  8. In Level 1 or 2 reset the timer by setting parameter t.St to rst.

 

Following a time out, the Timer Status parameter t.St can be set to rUn. The outputs will immediately go to ss.oP until the end of the timing period and the sequence will be the same as when the controller is power cycled.

 

As soon as the PV reaches the value set by SS.SP (50OC) the timer will stop and go to the end state.

 

At any time the Timer Status parameter t.St can be set to HoLd. The display will flash between HLd and the current setpoint and the outputs will remain at ss.oP until the hold condition is released.

 

Digital I/O can be configured as shown in section 5.2.16.