Carrier Aquaforce 30XA302 Installation, Operation And Maintenance Instructions

Also see for Aquaforce 30XA Series: Installation instructions Operation instructions User guide

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52The switch that has been selected for detecting reverserotation is Carrier part number HK01CB001. This switchopens the contacts when the pressure falls below 7 kPa. Theswitch is a manual reset type that can be reset after thepressure has once again risen above 70 kPa. It is criticalthat the switch be a manual reset type to preclude thecompressor from short cycling in the reverse direction.13.9 - Precaution for compressor power supply busbar connectionThis note applies to units using power supply bus bars withriveted contact block at the level of the connection cages inthe control box. During re-connection it is imperative to:• Engage each bus bar in the cage up to the stop• Ensure visually that the bus bars have good contact atthe connection areas: There must not be any freemove-ment between the bus bar and the connectionarea created by the fixing rivet of the contact block.Connection of the contactor or current transformer13.7 - Evaporator maintenanceCheck that:• The insulating foam is intact and securely in place.• The cooler heaters are operating, secure and correctlypositioned.• The water-side connections are clean and show nosign of leakage.13.8 - Compressor maintenance13.8.1 - Oil separatorCheck the correct operation of the heaters and check thatthey are well attached to the oil separator ring.13.8.2 - Integral oil filter changeAs system cleanliness is critical to reliable system operation,there is a filter in the oil line at the oil separator outlet. Theoil filter is specified to provide a high level of filtration (5 μm)required for long bearing life.The filter should be checked after the first 500 hours ofoperation, and every subsequent 2000 hours. The filter shouldbe replaced at any time when the pressure differentialacross the filter exceeds 200 kPa (2 bar).The pressure drop across the filter can be determined bymeasuring the pressure at the filter service port and the oilpressure port. The difference in these two pressures will bethe pressure drop across the filter, check valve, and solenoidvalve. The pressure drop across the check valve and solenoidvalve is approximately 40 kPa (0.4 bar), which should besubtracted from the two oil pressure measurements to givethe oil filter pressure drop.13.8.3 - Compressor rotation controlCorrect compressor rotation is one of the most criticalappli-cation considerations. Reverse rotation, even for avery short duration, damages the compressor.The reverse rotation protection scheme must be able todetermine the direction of rotation and stop the compressorwithin 300 ms. Reverse rotation is most likely to occurwhen-ever the wiring to the compressor terminals isdisturbed.To minimize the opportunity for reverse rotation, the follow-ing procedure must be applied. Rewire the power cables tothe compressor terminal pin as originally wired.For replacement of the compressor, a low pressure switchis included with the compressor. This low pressure switchshould be temporarily installed as a hard safety on the highpressure part of the compressor. The purpose of this switchis to protect the compressor against any wiring errors atthe compressor terminal pin. The electrical contact of theswitch would be wired in series with the high pressure switch.The switch will remain in place until the compressor hasbeen started and direction of rotation has been verified; atthis point, the switch will be removed.12 21 Power supply bus bar with riveted contact block2 Contactor or current transformer connection zone13.10 - Check of power factor correction capacitorsThe verification consists in measuring input current ofeach capacitor block. Absence of current despite capacitoris energized is an indication that there is a defect.Confirmation shall be done by removing the capacitorsand checking the underside.Defect Good