Daikin FWW02-20DA - User Manual

The Daikin FWW02-20DA is a ceiling concealed fan coil unit designed for air conditioning and hot-air heating applications. It is intended for hidden installation within a ceiling space, providing conditioned air through a duct system. The unit is part of a chilled water system, where it circulates water through a coil to either cool or heat the air before it is distributed into the conditioned space.

Important Technical Specifications

Water Circuit:

Minimum water-side pressure: 0.01 MPa
Maximum water-side pressure: 1.6 MPa
Minimum entering water temperature (cooling): 5°C
Maximum entering water temperature (cooling): 25°C
Water flow rate: 0.1-2.1 m³/h
Recommended operation range (cooling): 16-36°C
Maximum External Static Pressure (ESP): 100 Pa
Minimum ESP: 40 Pa

Power Supply:

Nominal single-phase voltage: 220-240V~ / 50 Hz
Operating voltage limits: ±10% Volt
Operating frequency limits: ±1 Hz
Power cord type: H05VV-F
Wire size: AWG16 (or 1.5mm²)

Water Quality Requirements (Base Value):

pH value (25°C): 6.5-8.0
Conductivity (25°C): < 800 µS/cm
Chloride (CI⁻): < 200 mg(CI)/L
Sulfate (SO₄²⁻): < 200 mg(SO₄)/L
Acid consumption (pH=4.8): < 100 mg(CaCO₃)/L
Full hardness: < 200 mg(CaCO₃)/L
Iron (Fe): < 1.0 mg(Fe)/L
Sulfide (S²⁻): 0 mg(S²⁻)/L
Ammonium (NH₄⁺): < 1.0 mg(NH₄⁺)/L
Silica (SiO₂): < 50 mg(SiO₂)/L

Dimensions (FWW02DA model):

A: 675 mm
B: 452 mm
C: 487 mm
D: 469 mm
E: 522 mm
F: 540 mm
G: 151 mm
H: 143 mm
J: 529 mm
K: 211 mm
L: 243 mm
M: 382 mm
Overall height (including hanging rods and connections): 187 mm (unit body 104 mm, plus 35 mm clearance top and bottom)
Condensate drain pipe: R3/4
Water return/supply: Rc3/4

Usage Features

Installation:

Designed for concealed ceiling installation, requiring sufficient space for the unit and maintenance.
Minimum height of 2.5m for free blow installations to prevent contact.
Requires proper hanging rods capable of supporting the unit's weight.
Unit must be installed level.
Air ducts should be galvanized steel, fire-proof, and sealed to prevent air leakage.
Drainage piping must be connected properly with a suggested slope of at least 1:50 to prevent water leakage.
Water filter should be installed in the chiller water pump inlet and evaporator inlet pipes to prevent blockages.
Flexible connector tubes are recommended for water pipe connections, sealed with tape.
The water system requires preliminary softening treatment to protect the plate exchanger from scaling and to maintain water flow.

Electrical Wiring:

All field wiring must comply with national wiring regulations.
The unit must be properly grounded.
A breaker device with at least 3mm contact separation must be installed at the power supply incoming line.
A main switch or other means for disconnection, with contact separation in all poles, must be incorporated in the fixed wiring.
An appropriate strain relief device is needed for power wires to the terminal box.
The unit cannot be parallel connected for electric wiring to avoid motor burning.
An all-pole disconnection device with at least 3mm clearances in all poles, and a residual current device (RCD) with a rated residual operating current not exceeding 30mA, must be incorporated in the fixed wiring.

Operation:

Before turning off the power supply, the remote controller's ON/OFF switch should be set to "OFF" to prevent nuisance tripping and automatic fan startup when power resumes.
An electric valve and thermostat should be installed to prevent condensation if chilled water supply continues while the fan motor is stopped.

Maintenance Features

Safety Precautions:

Always turn off the unit and cut the voltage by turning the line switch to OFF before any maintenance or cleaning.
Maintenance should only be performed by skilled personnel.
Use safety work gloves to avoid injury from metallic parts.

Periodic Maintenance:

Air Filter Cleaning:
- Access the equipment through the inspection panel.
- Remove the air filter by unscrewing fixing knobs.
- Wash the filter with lukewarm water or clean with compressed air for dry powders.
- Reassemble the filter after it has dried.
Heat Exchanger Cleaning:
- Check the heat exchanger condition before the summer season and ensure fins are not clogged.
- Remove the drain pan and drain guide to access the heat exchanger.
- Clean with compressed air or low-pressure steam, being careful not to damage the fins.
Condensate Discharge Check:
- Regularly check the condensate discharges, especially before summer operation.
Motor: The motor is maintenance-free due to self-lubricating bearings.
Initial Startup: After a long idle period, ensure no air is present in the heat exchanger when starting the units.

Troubleshooting: The manual provides a troubleshooting guide for common issues:

Unit does not run at all: Check for power failure, tripped circuit breaker, or if the switch is in the "Off" position.
Poor cooling or heating performance: Check for dirty/clogged air filter, obstacles near air inlet/outlet, air inside the heat exchanger, open doors/windows, or if the unit is running at low speed.
Unit leaks: Check for incorrect installation inclination or a clogged condensate discharge.

For unresolved issues, contact the dealer or service center.