Direct Expansion Coils; Antifreeze Electric Coil Section - Casals QUANTICA EEC Manual De Instalación, Operación Y Mantenimiento

Coil performance is normally rated for counter-flow circuit arrangement, consequently coils are provided with
water inlet at the bottom and downstream air flow, outlet at the top and upstream air flow. The stickers on the
unit with the respective inlet and outlet symbols placed near the headers respect this rule.
Furthermore, water circuit should be provided with:
1) water drain to be positioned at the unit lowest point (obligatory);
2) vent valve at the circuit highest point to allow easy replenishment (recommended);
3) shut-off valves, on water inlet and outlet, to allow coil disassembly for extraordinary maintenance;
4) for hot water coils, water pump electric interlock with the fan cycling device or circuit bypass, to avoid damages resulting
from overheated stagnating air, during fan shutdown periods.
Installer must obviously guarantee the requested value of water flow.

13.8.2 Direct expansion coils

Instructions given at points a) and b) of previous paragraph for water coils should be followed also in this case, bearing in mind
that the best coil performance is always obtained with the counter-flow arrangement. In this case coil supply is evidently the
one provided with the distribution header where the liquid line must be connected.
The refrigerant circuit must be made in accordance to the best state-of-the-art practice; in any case, the following recommen-
dations are to be followed:
1) coil is supplied with a holding charge of refrigerant or dehydrated nitrogen;
2) only refrigeration copper tubes should be used, tubes must be thoroughly cleaned, dehydrated and sealed until their use;
3) coil distributor should be cut only immediately before proceeding to brazing, which must be carried out in dehydrated nitrogen
atmosphere which must be forced inside tube to prevent undesired oxidation;
4) same criteria described in point 3) must be used when brazing liquid line to distributor;
5) refrigerant circuit must include appropriate controls and devices to guarantee proper system operation, coil is only a part
of the system.

13.9 Antifreeze electric coil section

A
EN
The antifreeze electric coil is supplied in a
sheet metal spigot fixed external of the main
unit, (on the fresh air inlet side) effectively
increasing the total length of the unit.
Below are the additional lengths according
to size, which are taken into account when
calculating the final length of the unit.
A
MOD.
[mm]
045
230
060
230
080
230
100
230
130
230
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