Using The Unit In Sub-Freezing Or Snowy Conditions - Mitsubishi Electric QAHV-N560YA-HPB Service Handbook

[ II Restrictions ]

[8] Using the Unit in Sub-freezing or Snowy Conditions

In areas where temperature drops to freezing
during the periods of non-use, blow the water out
of the pipes or fill the pipes with anti-freeze
solution.
Not doing so may cause the water to freeze, resulting
in burst pipes and damage to the unit or the
furnishings.
In areas where temperature drops to freezing, use an
anti-freeze circuit and leave the main power turned on
to prevent the water in the water circuit from freezing
and damaging the unit or causing water leakage and
resultant damage to the furnishings.
• Remove the snow off the unit before switching on the ON/OFF switch.
• In areas where the outside air drops below freezing, leave the main switch turned on even when the unit will not be
operated for four days or longer. Leave the switch on the water circulation pump turned on if the pump is
connected to a separate circuit.
• If the unit is left turned off for a while (e.g., overnight) when the outside temperature drops below freezing, the
water in the water circuit will freeze and damage the pipes and the heat exchanger.
• The recommended electric circuit has an anti-freeze circuit. For this circuit to function, the main power must be
turned on.
• If the water circulation pump is connected differently from the recommended way, make sure the circuit has some
type of anti-freeze function*.
(* A function that automatically operates the water circulation pump to prevent the water in the circuit from freezing
when the water temperature drops.)
In cold areas (where the lowest outside temperature drops below freezing), if power is not supplied while the unit is
stopped during winter, make sure to completely drain water from the piping. Failure to do so may cause the residual
water to freeze, resulting in damage to the heat exchanger.
Before using the unit, perform a test run such as water fill test or air bleeding test again.
Drainage method
Procedure
1. Disconnect the outlet pipe.
2. Disconnect the inlet pipe.
3. Open the drain trap at the T-shaped part.
4. Completely remove water by blowing compressed air or nitrogen (cylinder) of 0.5 to 0.6 MPa into the outlet pipe.
1. Outlet pipe
4. Blow compressed air
or nitrogen.
HWE1517A
2. Inlet pipe
In areas where temperature can drop low enough
to cause the water in the pipes to freeze, operate
the unit often enough to prevent the water from
freezing.
Frozen water in the water circuit may cause the water
to freeze, resulting in burst pipes and damage to the
unit or the furnishings.
3. Drain trap at the
T-shaped part
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