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10
MAINTENANCE AND PERIODICAL CONTROLS
If the temperature drops below 0°C there is serious danger of frost: add a mixture of water and glycol in the plant,
otherwise drain the hydraulic circuits of the plant and of the heat pump.
WARNING: if the ambient temperature becomes lower than -15°C ,
in case the unit is turned off and powered down also for short periods, it’s compulsory to drain the plant and the
hydraulic circuit of the unit by the mixture of water and glycol. Otherwise, the circulator may be irreversibly
damaged.
WARNING: the operation, although it was transient, with water temperatures below +5°C is not guaranteed on the
basis of the limits set out in Paragraph 20.4. Before you turn the unit on after a long off period, make sure that the
temperature of the mixture of water and glycol is higher than or at least equal to +5°C.
WARNING: All the operations described in this chapter HAVE TO BE CARRIED OUT BY TRAINED STAFF ONLY. Before
any operation or before entering the inner components of the unit, be sure that the power supply is disconnected.
The compressor’s heads and discharge pipes are usually at high temperature levels. Be very careful when operating
in their surroundings. Aluminium coil fins are very sharp and can cause serious wounds. Be very careful when
operating in near them. After maintenance operations, re-install the cover panels, and fix them by means of screws.
The refrigerant circuits must not be filled with different gas other than that indicated on the nameplate. The use of a
different refrigerant can cause severe damage to the compressor.
It’s forbidden to use oils other than those specified in this manual. The use of different oil can cause serious damage
to the compressor.
WARNING: MOVING PARTS, RISK OF DEATH.
Disconnect the power supply and ensure that the fan is stopped before opening the front panel.
The temperatures of heads and exhaust piping of the compressor are usually high.
Pay attention to the surfaces of the driver boards heat sinks (see Chapter 23), which can become very hot.
Be careful when working near condensing coils.
The aluminum fins are very sharp and can cause serious injuries.
