Rail Heat - Danfoss AK-CC55 Compact User Manual

AK-CC55 Compact
Sequential control
Compressor steps are controlled in the same manner as described for cyclic control, but compressor step 1 will
always be started first and cut out as the last one. No time equalization is available in sequential control mode.
Thermostat band
In thermostat band 2, it is possible to disable the operation of the second compressor.

Rail heat

It is possible to pulse-control the power to the rail heat in order to save energy. Pulse control can either be
controlled according to day/night load or dewpoint.
Relay or analogue output
A relay output can be used when long cycle times are permitted. If fast pulsing is required, the AO1/PWM output
can be used. The output must be connected to an external power solid state relay. The cycle time must be
configured for the relay output in o43 or for analogue output in P82.
Pulse control according to day and night
Various ON periods can be set for day and night operation. A cycle time is set as well as the percentage part of the
period in which the rail heat is ON.
Figure 20: Rail heat control, day/night load.
Pulse control according to dewpoint
In order to use this function, a system manager of the type AK-SM is required which can measure ambient
temperature and humidity to calculate dewpoint and distribute to the appliance controllers. For this the rail heat's
ON period is controlled according to the distributed dewpoint.
Two dewpoint values are set in the appliance control:
• One where the effect must be max. i.e. 100%. (o87)
• One where the effect must be min. (o86)
At a dewpoint which is equal to or lower than the value in 086, the effect will be the value indicated in o88. In the
area between the two dewpoint values, the controller will manage the power to be supplied to the rail heat.
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