KEMPOWELD 4200, 4200W, 5500W / 0531 – 11© KEMPPI OY2.7.2. Operation switchesIn zero (O) position of the power source´s main switch also all operations of the cooling unit are stopped.Cooling unit´s main switch O / IThe electric supply for the pump motor is switched on by main switch key O / I, where the pilot lamp indicatesthe standby state I. In zero (O) position of the main switch the pump motor cannot get started, but the switchesand pilot lamps are operating.Fuse (F2)The fuse on the front wall of the cooling unit is short-circuit protection. Use the fuse size and type according tomarkings. If the fuse is blowing again, send the unit to service.Selecting switch for gun’s cooling mode (Sw1)The Kempoweld equipment are suitable to be used with both air- and water-cooled guns. Select cooling mode andcorrect use and protection functions with switch on the cooling unit´s panel.If your choice is GAS, but you are using water-cooled gun, no protection is operating. The pilot lamp is illuminatedin position I of the cooling unit´s main switch. However, the control does not start the pump.The wrong choice will destroy the gun in short time!If your choice is (water), but you are using air-cooled gun, the pump gets started by pressing on the trigger, ifthe cooling unit´s main switch is in position I.Test switch (Sw5)By TEST switch on the panel of the cooling unit you can circulate water without starting welding. It is used forfilling the gun and interconnection cable with cooling water before starting welding. By disturbance situations youcan always test the water circulation. Always check entry of return water into the tank before welding!Pilot lampsPilot lamp for overheating (Hw4)If the cooling water in the tank is overheating, the thermal protection will stop the power source. Operation of thecooling unit is continued for ca. 5 - 7 min automatically. The pilot lamp will switch off after the water in the tankhas cooled down, after which the welding will start from the gun triggering.Pilot lamp for lacking liquid pressure (Hw3)If the pump does not step up sufficient supply pressure, e.g. when the water is running out or by disturbances inthe pump, the whole equipment will stop after ca. 5 s and the red pilot lamp illuminates. Check the equipment likeby the installation. See paragraph for Operation disturbances.Operating controlThe water circulation gets automatically started, when you are pressing on the gun trigger. The post-circulationof water will continue for ca. 5–7 min. after the weld end. The time is always counted from the latest trigger re-lease.3. OPERATION DISTURBANCESBy the operation or functional disturbances take the measures according to the following list.If the disturbance cannot be eliminated, check the equipment according to the paragraphs Installation andMaintenance, and take contact with Authorized Kemppi repair shop.The pump does not get started by test switch:– check the fuse on the front plate of the cooling unit– check the fuse on the rear plate of the power source– check position for cooling mode selecting switch– check positions for main switchesThe water does not circulate by lever switch:– check the tank filling volume– disconnect the connector for the return water hose of the gun from the rear wall of the cooling unit and usethet test switchIf the water is pumped, close the connector and run again by the test switch