Protecting The Unit From Frost - emmeti EH Série Manuel D'installation Et D'utilisation

II.6.5.3 Auxiliary thermal source
An auxiliary generator is a heat generator that runs alternatively to the heat pump; typically, it is a boiler. When the alternative generator is activated, the
heat pump and all its auxiliaries are off, even if powered. The auxiliary generator can be enabled only for heating the systems.
Operation of the auxiliary source
The auxiliary generator can be activated according to three modes:
- manually;
- for an outdoor temperature set point;
- for a convenience criterion based on the costs of electricity and fuel (methane and butane)
- for heat Pump malfunction.
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Condensation drain tray
EH models are complete with a condensate drain tray and heating
electrical resistance that prevents ice from developing under the coil in
cases of harsh temperatures. Electrical resistance is regulated
according to the outdoor temperature. The factory-set activation set-
point is 2°C.
The condensate drain tray has two draining points to facilitate water
evacuation. You must channel condensate draining. When the outdoor
temperature is around zero, the water normally produced during the coil
defrosting could form ice and make the flooring near the unit installation
area slippery.
We recommend diverting using an inclined pipe, minimising the number
of curves and pressure drops to facilitate draining.
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SECTION II: INSTALLATION AND MAINTENANCE
1.
2.
3.
4.
5.
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II.6.6

PROTECTING THE UNIT FROM FROST

IMPORTANT!
If the master switch is opened, it cuts the power
supply to the plate exchanger heater and the
compressor crankcase heater. The switch should
only be disconnected for cleaning, maintenance or
repair of the machine.
When the unit is running, the control board protects the water side heat
exchanger from freezing by triggering the antifreeze alarm, which stops
the machine if the temperature of the sensor fitted on the heat
exchanger reaches the set point value and simultaneously maintains
the circulation pump active.
With the unit OFF but powered, if the water sensor on the outlet of the
heat exchanger detects a temperature lower than the antifreeze set-
point, it activates the circulation pump and the antifreeze resistance of
the heat exchanger.
IMPORTANT!
When the unit is out of service, drain all the water
from the circuit.
If the draining operation is felt to be too much trouble, ethylene glycol
may be mixed with the water in suitable proportions in order to
guarantee protection from freezing.
IMPORTANT!
Mixing the water with glycol modifies the
performance of the unit.
The use of ethylene glycol is recommended if you do not wish to drain
the water from the hydraulic system during the winter stoppage, or if the
unit has to supply chilled water at temperatures lower than 5°C The
addition of glycol changes the physical properties of the water and
consequently the performance of the unit. The proper percentage of
glycol to be added to the system can be obtained from the most
demanding functioning conditions from those shown below. Table "H"
shows the multipliers which allow the changes in performance of the
units to be determined in proportion to the required percentage of
ethylene glycol.
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EH
Inertial storage tank
Hydraulic circuit breaker
Boiler
Shut-off components not managed