Daikin EWAT_B Series Installation, Maintenance And Operation Manual

Contents

Daikin EWAT_B Series Installation, Maintenance And Operation Manual Manual pdf 19 page image

D-EIMAC01706-18EN - 19/32Simultaneous single and three-phase loads and phase unbalance can cause ground losses of up to 150 mA during normalunit operation. If the unit includes devices that generate higher harmonics, such as an inverter or phase cut, ground lossescan increase to much higher values, about 2 A.The protections for the power supply system must be designed according to the values mentioned above. A fuse must bepresent on each phase and, where provided for by the national laws of the country of installation, a leak detector to earth.This product complies with EMC (Electromagnetic Compatibility) standards for industrial environments. Therefore it is notintended for use in residential areas, e.g. installations where the product is connected to a low voltage public distributionsystem. Should this product need to be connected to a low voltage public distribution system, specific additional measureswill have to be taken to avoid interference with other sensitive equipment.Before any electrical connection work to the compressor motor and / or the fans, make sure that thesystem is switched off and the main switch of the unit is open. Failure to observe this rule couldresult in serious personal injury.2.13.1 Cable requirementsThe cables connected to the circuit breaker must respect the insulation distance in the air and the surface isolation distancebetween the active conductors and the earth, according to IEC 61439-1 table 1 and 2, and to the local national laws.The cables connected to the main switch must be tightened using a pair of keys and respecting the unified clamping values,relative to the quality of the screws of the washers and nuts used.Connect the earth conductor (yellow / green) to the PE ground terminal.The equipotential protection conductor (earth conductor) must have a section according to table 1 of EN 60204-1 Point5.2, shown below.In any case, the equipotential protection conductor (earth conductor) must have a cross section of at least 10 mm2, inaccordance with point 8.2.8 of the same standard.2.13.2 Interconnection cablesThe unit cannot operate without the flow of water, thanks to the intervention of the flow switch. However, in order to havedouble safety, it is mandatory to install a water pump status contact in series with the contact of the flow switch(es),to prevent the unit from operating even without the pump starting. If the unit is operated without the flow of water, itwill cause serious damage (freezing of the evaporator).- Clean contacts: the controller has some clean signal contacts. These contacts can be wired as indicated in thewiring diagram. The maximum permissible current is 2 A.- Remote inputs: in addition to the clean contacts, it is also possible to install remote inputs. For installation, referto the wiring diagram.Table 5 - Table 1 of EN60204-1 Point 5.2Section of the copperphase conductorsfeedingthe equipmentS [mm2]Minimum cross-sectionof the external copperprotection conductorSp [mm2]S ≤ 1616 < S ≤ 35S > 35S16S/2Phase unbalanceIn a three-phase system, the excessive imbalance between the phases is the cause of the engine overheating. Themaximum permitted voltage unbalance is 3%, calculated as follows:𝑆𝑏𝑖𝑙𝑎𝑛𝑐𝑖𝑎𝑚𝑒𝑛𝑡𝑜 % = (𝑉𝑥 − 𝑉𝑚) ∗ 100𝑉𝑚where:Vx = phase with greater unbalanceVm = average of the tensionsExample: the three phases measure 383, 386 and 392 V respectively. The average is:383 + 386 + 3923 = 387 𝑉The unbalance percentage is:(392 − 387) ∗ 100387 = 𝟏. 𝟐𝟗 %less than the maximum allowed (3%).