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3.3 Additional Remarks of Special Functions
3.3.1 Single-phase phase-shift trigger output
When OPt is set to PHA, installing a K5 module in OUTP slot can single-phase phase-shift trigger a TRIAC or 2
inverse parallel SCRs. It can continuously adjust heating power by control the conduction angle of thyristor. With
non-linear power adjustment according to the characters of sine wave, it can get ideal control. The trigger adopts
self-synchronizing technology, so it can also work even when the power supplies of the instrument and the heater are
different. Phase-shift trigger has high interference to the electric power, so user should pay attention to the
anti-interference ability of other machines in the system. Now the K5 module can be only used in 50Hz power
supply.
3.3.2 Alarm blocking at the beginning of power on
Some unnecessary alarms often occur at the beginning of power on. In a heating system, at the beginning of power
on, its temperature is much lower than the setpoint. If low limit and deviation low limit are set and the alarm
conditions are satisfied, the instrument should alarm, but there is no problem in the system. Contrarily, in an
refrigerating system, the unnecessary high limit or deviation high limit alarm may occur at the beginning of power on.