Carrier 30KAV-ZE Series - Page 85

Hydraulic connection with option 325:
Option 325 is used to make the hydraulic connection between the
two recovery heat exchangers to obtain a hot water inlet/outlet.
Option 49/50: Without option 325
Option 49/50: With option 325
NOTE:
Option 41C ensures thermal insulation of the recovery and
evaporator water pipes to protect them from frost.
12.4.3 - Heat recovery operation
The heat recovery mode is activated and deactivated via a
three-way valve and/or a variable ow pump on the hot water
hydraulic circuit. The control system will then adapt to the request
by regulating the ow of water into the condensation exchangers
and the ow of air into the air-cooled condenser.
Variable water ow control:
A 0-10 V output is available on the unit electronic board to control
a three-way valve or a variable ow pump. It is necessary that one
of these two components is installed to ensure a uid transition
between recovery mode and standard mode. The control system
will start heat recovery, and maintain the hot water setpoint
temperature.
(See the control manual)
Controlling the recovery capacity:
Two operating modes are available for options 49 and 50:
Optimised recovery mode: (congure by default with option 50)
This mode is used to adjust the recovered capacity by gradually
reducing the ventilation speed to obtain the congured control
point. When there is no longer a recovery request, the control
system increases the ventilation speed and cuts o󰀨 the water ow
with a command on a three way valve or variable ow pump.
Economy mode: (congure by default with option 49)
This mode enables recovery of desuperheating only.
The machine's e󰀩ciency is not a󰀨ected by the recovery request.
The control system only adjusts the water ow and does not alter
the ventilation speed.
Frost protection:
The heat recovery condensers are equipped with electrical heaters
which protect them against frost. They are activated if the outdoor
air temperature is less than 3 °C and if the machine is not in chilled
water production mode.
NOTE: If there is glycol in the hot water loop, it is possible to
congure it and deactivate the frost protection on the water-
cooled condenser side.
12 - OPTIONS
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