AK-PC
551
Technical
brochure RC8CF102 © Danfoss 08-2014
5
Introduction
Compressor combinations
The compressor capacity can be controlled according to the
suction pressure Po or a media temperature sensor S4�
AK-PC 551 covers a variety of compressor combinations�
Inputs and outputs
All in- and outputs of an AK-PC 551 controller can be configured
for various functions and signal types:
• 8 analogue inputs for pressure transmitters and temperature
sensors�
• 6 digital relay outputs for compressors, fans, alarm�
• 2 digital solid state outputs for PWM control of Digital scroll
or Stream compressor� If not used for this purpose they can
be used as normal relay outputs�
• 2 analogue outputs for speed control of compressors and
condenser fans�
Speed control of all fans
Step control of all fans
Condenser combinations
The condenser capacity can be controlled according to the
condensing pressure Pc or a media temperature sensor S7
The condenser can be controlled in two ways:
• Speed control of all fans
• Step control of single fans