Alfa Laval Optigo CD Instrucciones De Instalación página 6

Air Defrost
This method can only be adopted if the room temperature is above 5° C.This requires the stopping of the pump
and the natural heating of the evaporator by forced air circulation through the finned coil by the fans.
Electric Defrost
Electric defrost consists of a series of resistance heating elements that are inserted through the finned coil to heat
the fins during the defrost mode. The system can be used for cold room temperatures above -20° C.The heaters
are electrically connected to a common box. Connections to the power supply must be made following the
electrical drawing.
During defrosting, the heaters are powered on, while the cooling is off. It is good practice to control the defrost
using a timer and a thermostat in order to avoid any overheating. Do not allow long heater on times that cause coil
steaming.
Before making the electrical connection, make sure that the system is disconnected from the power
supply and cannot be accidentally switched on, even by other parts.
Start-up and operation
Start-up
Before starting up the unit, readiness for operation must be checked and determined using the following checklist:
All refrigerating system connections must be checked for leaks and correct.
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All screw connections (particularly to fans), fastenings, electrical connections etc. must be checked for
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correct installation.
Before starting up, the wiring must be checked for correct installation and the electrical safety measures
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must be checked for correct functioning.
All supply lines to the connecting boxes must be sealed in accordance with their insulation class.
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The supply line must always be fused in accordance with the smallest wire cross-section.
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Attention!
When the connection box is powered for the first time or in case of power cut the unit open and close
itself one time for diagnostic reason.
To operate the unit, the entire system must be in operation, including the electrical installations.
The unit has to be switched on by opening the relevant valves on the inlet and outlet side of the entire system and
by connecting it to the electrical system.
Taking out of service and final shutdown
The unit is taken out of service by shutting it off from the system. In this case, the fluid-carrying pipes must be shut
off from the refrigerating system; the fans and, if installed, the electrical defrost heating elements must be
disconnected from the electrical installation.
When shutting down the unit, take into account max. Operating pressure! If necessary, take precautions so
that it cannot be exceeded.
© Alfa Laval
IM100535 Rev 01
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