KGL Operating Manual – UA 412 S
2019-01-14
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5.4 Safety chain
The cooling is switched off if the safety chain digital input 4, terminals D41/42) is tripped by integrated safety
elements such as high pressure switch, Klixon, FC fault etc.
The safety chain is controlled inverted; a 230 V signal at the digital input represents the OK state.
The controller initiates an alarm (message "Safety Chain") if the safety chain is tripped (digital input becomes
de-energised).
Warning about dangerous electrical voltage!
Danger of electric shock! BEFORE connecting and disconnecting, it must be checkedthat no voltage
at the 230 V AC digital inputs! The controller and connected voltage carrying components
is present
remain supplied with power!
5.5 Cooling
5.5.1 Compressor enable according to supply air and return air
Dual on-off control according to supply air / return air
Alternatively the regulation is performed using two temperature sensors (suppl< air or return air sensor of the
pilot case). The compressor enable is removed (switches off) if any of the two sensors has reached or
undercut its specified setpoint minus half of the specified hysteresis (switch-off value). The compressor enable
is granted with the exceeding of the setpoint plus half of the specified hysteresis (switch-on value) of that
sensor that had removed the compressor enable.
If only one of the sensors (supply or return air sensor) is fitted, then the regulation is carried out according to
this sensor alone.
The speed control for the compressor(s) is performed with the granting of the compressor enable. Details for
this can be found in chapter
Controller type SPIR410
Controller type SPIR290
