Panasonic CS-KS30NKU Technical & Service Manual

Contents

Panasonic CS-KS30NKU Technical & Service Manual Manual pdf 102 page image

266. Air PurgingAir and moisture remaining in the refrigerant systemhave undesirable effects as indicated below. Therefore,they must be purged completely. pressure in the system rises operating current rises cooling (or heating) efficiency drops moisture in the air may freeze and block capillary tubing water may lead to corrosion of parts in the refrigerantsystem Air Purging with a Vacuum Pump (for Test Run)(1) Check that each tube (both narrow and wide tubes)between the indoor and outdoor units have beenproperly connected and all wiring for the test runhas been completed. Note that both narrow andwide tube service valves on the outdoor unit arekept closed at this stage.(2) Using an adjustable wrench or box wrench, removethe valve caps from the service valve on both nar-row and wide tubes.(3) Connect a vacuum pump and a manifold valve (withpressure gauges) to the service port on the widetube service valve. (Fig. 57)(4) With the “Lo” knob of the manifold valve open, runthe vacuum pump. The operation time for the vacu-um pump varies with tubing length and the capacityof the pump. The following table shows the amountof time for evacuation:Table 7HiLoIndoor unitOutdoor unitManifold valve(Exclusively for R410A)PressuregaugeVacuum pumpCharging hose(Exclusively for R410A)Vacuum pump adapter(Exclusively for R410A)(with reverse flow prevention)Fig. 57CAUTION Be sure to use a manifold valvefor air purging. If it is not avail-able, use a stop valve (field sup-ply) for this purpose. The “Hi”knob of the manifold valve mustalways be kept closed.The required time in Table 7 is calculated based on theassumption that the ideal (or target) vacuum conditionis around 10 mmHg abs.NOTERequired time for evacuation when100 liter/h vacuum pump is usedIf tubing length is If tubing length isless than 33 ft. (10 m) more than 33 ft. (10 m)10 min. or more 15 min. or moreCAUTION The service port on the wide tubeservice valve uses a Schrader corevalve to access the refrigerant sys-tem. The valve core is similar tothose used in automobile tires.Therefore, be sure to use a vacuumhose connector which has a push-pin inside.To prevent other refrigerants from being mistakenlycharged to units which use R410A, the size of thecharge port on the service valve is different from theone for other refrigerant types. For servicing such asrecharging, the specified charging hose, manifold andvacuum pump adapter (with reverse flow prevention)for R410A must be used.NOTE