Specifications

28 RK0YG302 © Danfoss 05/2007
AK-PC 420
Application
AK-PC 420 is a complete capacity control of a dry cooler including
fans, three-way valve, pumps and heat recovery.
Advantages
• Complete capacity control of dry cooler
• Option of choosing control sensor (S7/Pc and/or S8)
• Control according to one loop or two loop principles for opti-
mum operation on all system types
• Fan speed control
• Fan connection according to sequential or rotational operation
• Reference according to ambient temperature
Control
• Capacity control according to condensing pressure Pc or brine
return temperature S7.
• Reference temperature according to xed settings with option
of overriding via ambient temperature or external 0-10 V signal.
Separate reference for heat recovery.
• For one-loop control a capacity adjustment of the three-way
valve and fans is carried out via Pc or S7.
• For two-loop control individual capacity adjustment of the two
circuits is carried out: three-way valve via Pc/S7 and fans via S8.
This ensures that even dicult systems with long tubes can be
handled optimally.
Functions
• Control and monitoring of max. 6 fans via step or speed control
• Sequential or rotational fan operation
• Three-way valve control
• Over-riding of reference temperature via ambient temperature
Sc3 or 0-5 V d.c. signal
• Separate reference temperature for heat recovery with overrid-
ing via 0-5 V d.c. signal
• Input for start and outlet for activation of heat recovery
• Control and monitoring of two twin pumps with rotational
operation
• Safety function for high condensing pressure
• Alarm relay
• External control start/stop
Operation
All operation takes place either via data communication or by
connection of a display of the type EKA 164. Extra readout via
display of the type EKA 163.
Dry cooler
AK-PC 420
Additional information!
Manual: RS8EL