Danfoss ADAP-KOOL AK-PC 783 Design Manual page 111

P-regulation
With P regulation the reference will be 0 degrees above the meas-
ured outdoor temperature. The proportional band Xp indicates
the deviation with 100% condenser capacity.
Heat recovery function
The heat recovery function can be used on the installation
when you want to make use of warm gas for heating purposes.
When the function is activated the reference for the condenser
temperature will be raised to a set value and the attached relay
outlet is used to activate a solenoid valve.
The function can be activated in two ways:
1. A digital input signal is received
In this instance, the heat recovery function is activated via
an external signal from, for example a building management
system. When the function is activated the reference for the
condenser temperature will be raised to a set value and the
attached relay outlet is used to activate a solenoid valve.
Pc ref
DI
2. Use of a thermostat for the function.
This function can be used with advantage where the heat
recovery is used to warm up a water tank. A temperature sensor
is used to activate/deactivate the heat recovery function. When
the temperature sensor becomes lower than the set cut in
limit, the heat recovery function is activated and the reference
for the condenser temperature will be raised to a set value
and simultaneously the chosen relay outlet is used to activate
a solenoid valve which leads the warm gas through the heat
exchanger in the water tank. When the temperature in the tank
has reached the set value, the heat recovery is cut-out again.
In both cases it applies that when the heat recovery function is
de-activated, the reference for the condensing temperature will
then decline slowly in accordance with the set rate in Kelvin/
minute.
AK-PC 783 Capacity controller RS8GN202 © Danfoss 11-2013
Limitation of the reference
To safeguard yourself against a too high or too low regulation
reference, a limitation of the reference must be set.
PcRef
Max
Min
Forced operation of condenser capacity
Forced operation of the capacity can be arranged where the nor-
mal regulation is ignored.
The safety functions are cancelled during forced operation.
Forced operation via setting
The regulation is set to Manual.
The capacity is set in percent of the regulated capacity.
Forced operation of relays
If the forced operation is carried out with the switches at the
front of an extension module, the safety function will register
any exceeding of values and transmit alarms, if required, but the
controller cannot cut the relays in or out in this situation.
111