Hydraulic Connections - Carrier 42KY Instructions D'installation, De Fonctionnement Et D'entretien

The ducts used should be insulated to prevent condensation. (Fibreglass 12-25 mm thick)
- Remove the plug from the fresh air inlet.
- Position the duct on the connection sleeve.
- Place a retaining clamp around the duct in contact with the connection sleeve.
- Tighten the clamp and check the integrity of the connection.
Guard against condensation (no valves open when the ventilation is switched off).

4.3. Hydraulic connections

Water always flows into the bottom of the coil and exits at the top.
The pipes are positioned in the suspended ceiling as shown in Fig. 7.
The coils are equipped with a header coupling with flat face swivel nuts with a female thread, diameter G½˝ and an O-ring.
(Supplied).
The header coupling is equipped with an air vent (Fig. 8, a) at the high point with partial draining at the low points (Fig. 8, b) that
can be operated using a 7 mm Allen key or a flat-blade screwdriver.
Recommendations for air-bleeding or draining the unit.
Before working on the unit, make sure that the power supplies are switched off and locked.
Only experienced, qualified technicians may work on the machine for the purposes of installation and maintenance. They must
be provided with personal protective equipment (PPE).
The technician must take all necessary precautions to recover any water drained during the bleeding or draining operations.
Particular attention must be paid to the risk of overflowing and splashing.
- To bleed the air, undo the bleed screw by no more than three turns (Fig. 8, a).
- To drain, hydraulically isolate the unit from the network and undo the drain screw by no more than 3 turns (Fig. 8, b).
IMPORTANT:
The coil can be partially drained, however precautions must be taken during winter if the installation is shut down. To drain
completely, air must be blown through the circuit.
Once the hydraulic connections are completed, it is not necessary to insulate the valves to prevent condensation (unless
specifically required for the particular valves). A naturally inclined ABS auxiliary condensate drain pan is supplied with the unit.
This recovers condensate from the valves and coil (from the main pan) and drains it via gravity or using a condensate drain pump
(supplied as an option).
● Installation
To avoid damaging the valves or couplings, never tighten to more than 3.5 dNm torque. Use two wrenches,
one to hold and the other to tighten to ensure a tight seal.
Always fit the valve with the flow in the right direction. On the 2 couplings, the direction of flow should be
A → AB (A being connected to the coil and AB to the hydraulic network).
The maximum allowable differential pressure for factory fitted valves (open or closed) is 100 kPa.
We recommend not exceeding 60 kPa. Refer to the valve manual for specific supplies.
● Design
The installation of the hydraulic system is crucial to the correct operation of the system. Drain valves should therefore be placed
at the appropriate points and in sufficient number. In addition, strainers should be fitted, as well as vents at circuit high points,
balancing tees and shut-off valves on each coil and, if necessary, pressure relief valves.
● Pressure safety
The installation must be protected against any risk of overpressure. Special care must be taken to protect against the risks linked
to expansion of the heat-transfer fluid and to the total hydrostatic pressure.
● Filtration:
An efficient filtration system (recommended mesh size of 0.5 mm) should be fitted on the supply water and return water lines.
● Flushing:
The system must be flushed completely and filled with treated water to prevent the build-up of scale or sludge in the circuit.
When flushing the system, set the unit thermostatic or modulating valves to 'bypass' to prevent any sludge or impurities
from entering the coil:
- Opening the thermostatic valve:
There are two options:
1) Remove the servomotor and fit the cap, which will apply pressure to the valve stem, thereby driving the valve to bypass.
2) Request that the control valve opens via the controller.
A A AB AB
B
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