The laser cutting machine of MORN LASER is sold all over the world. The temperature in some countries exceeds 40℃. The laser cutting machine needs to pay attention to safety at all times when working in this high temperature environment, especially the chiller. Because the water-cooled machine is the core of controlling the temperature of the laser cutting machine, any carelessness can easily cause the temperature to become too high and burn the laser. So, MORN LASER is here to remind everyone to pay attention to what matters about the water chiller.

Possible problems with water chillers

  1. Compressor overload warning light alarms. Poor heat dissipation will cause the condenser’s condensing temperature and corresponding condensing pressure to be too high, so that the high-pressure part of the pressure controller will act, and the compressor will be protected against overload. The shutdown of the compressor will affect the normal use of customers. The chiller should be placed in a location with good ventilation and heat dissipation.
  2. The pressure gauge is abnormal. When the chiller is in normal operation, the high pressure pressure should not be greater than 2.0MPA. If it exceeds this pressure, the condenser has poor heat dissipation. The solution is to clean the dust on the condenser fins with high pressure gas. Equipment without pressure gauges regularly clean the heat dissipation of the condenser. The low-pressure pressure should not be less than 0.2MPA. If it is lower than this pressure, it means that the condenser has fluorine leakage or the throttling part is dirty.
  3. The cooling effect is reduced. If the water tank is not cleaned for a long time, the evaporator inside the water tank will cause poor heat and cold exchange due to microorganisms, which will affect the cooling effect. Customers are requested to clean the water tank regularly and change the water frequently. Generally, the purified water is replaced once a month, and the water tank is cleaned (cleaned with detergent) at the same time to ensure the water quality of the chiller is clean.
  4. Water pressure alarm. It is normal when the water pressure is around 0.3MPA, and it will cause flow alarm output when abnormal. In order to avoid the abnormal flow of the chiller, please check the filter element and the internal filter of the water tank regularly for dirty and blocked phenomenon.

Solutions to problems with water chillers

  1. The chiller is not cooling: observe whether there is a compressor overload display on the chiller control panel.
  • Display: There are generally 3 situations in which the compressor is overloaded, high-voltage overload, low-voltage overload and current overload.

①. It can be judged as high pressure overload if the pressure controller reset button cancels the compressor overload display.

There are several reasons for high-pressure overload. The fan does not turn, the solenoid valve does not open, the equipment does not ventilate and the heat dissipation is poor, and the condenser is dirty.

Troubleshooting: Place the chiller in a position with good ventilation and heat dissipation, blow the dust on the condenser fins with an atmospheric pressure of about 1MPA, and then observe whether the high-pressure pressure of the compressor after working is lower than 2MPA, the fan does not rotate and the solenoid valve is stuck It is an accessory problem, just replace it.

②. Observe the pressure gauge, the high pressure and low pressure are lower than 0.2MPA, it can be judged as low pressure overload.

Similar to this situation, the fluorine system of the equipment must have leaked fluorine.

Troubleshooting: pressure the equipment to check the leaks, repair the leaks after the leaks are found, evacuate, pressurize the oil, add fluorine, add fluorine according to the weight marked on the nameplate, and professionals can add fluorine according to the pressure.

③. If the compressor overload display is cancelled by the thermal overload reset button, it can be judged as current overload.

Failure reason: Current overload means that the compressor current exceeds the rated current, and overload protection. Under normal circumstances, only the lack of phase of the compressor and high ambient temperature will cause current overload.

Troubleshooting: Improve the working environment, check the reasons for the lack of phase of the compressor, first check whether the three-phase resistance of the compressor is normal (three-phase balance, resistance about 5Ω is normal), abnormal is the compressor is broken, check whether the compressor line There is poor contact and whether the AC contactor is missing phase.

  • No display: Observe whether the compressor is working without displaying the compressor overload.

①Work: Observe the working pressure. When the compressor is working, the high pressure and low pressure are close to balance, and the fan blows cold or slightly hot air, which can be judged as the solenoid valve card or the compressor is broken; observe that the high pressure is normal and the low pressure is low. It can be judged that the expansion valve is adjusted too small, dirty, blocked, broken, and the evaporator surface is dirty, and the conversion efficiency is low.

②Not working: Check whether the output of all the electrical components of the AC contactor of the compressor is normal. For example, the AC contactor of the compressor of the 7HP equipment has the normally open point of the intermediate relay 1 output for the delay, and the delay is normally open for the compressor AC Contactor, AC contactor output to the press, any electrical device output is abnormal, it can be judged that the electrical device is broken.

  • After displaying for a few seconds, it will reset automatically. This fault is generally the expansion valve adjustment is too small or the expansion valve failure.

Troubleshooting: Adjust the expansion valve to the maximum position (clockwise adjustment is to reduce, counterclockwise to increase), and see if this fault will occur. If the fault is cancelled, then observe the low pressure operating pressure to see if it is normal. At that time, the pressure will be too high. If the pressure is too high, adjust the expansion valve down; if there is no response when adjusting the expansion valve, it means that the expansion valve is broken, just replace one.

  1. There is no display after the device is powered on

First observe the working indicator of the phase sequence relay. If only one light is on, it means that the three-phase electrical connection is reversed. Just replace any two phases at the power supply. If two lights are on and the controller is still not working, then check whether the normally open point of the phase sequence has power. If there is no power, the phase sequence is broken and need to be replaced; if there is power, check whether there is power at the power supply of the controller. If the electric controller does not work, it means the controller is broken. If there is no electricity, check whether the power cord from the phase sequence normally open point to the controller power supply is faulty. If there is a problem, replace a power cord.

  1. Flow alarm

Flow alarm means that the flow is insufficient and the flow switch is activated.

There are generally three reasons for the failure: 1. The external resistance is too large, the return water flow is small, and the alarm setting is too large. This failure can be solved by adjusting the flow switch; 2. There is air inside the pump. Troubleshooting: In the case of power failure, unscrew the drain screw, and then tighten it after water overflows. 3. The filter element and the internal filter of the water tank are dirty and blocked. Troubleshooting: Replace the filter element and clean the water filter.

  1. Water level alarm

Water level alarm is an alarm method caused by insufficient water level in the water tank. When a water level alarm occurs, first observe whether the water in the water tank exceeds the water level switch. If not, fill the water up. If the water level exceeds the water level switch and alarm, check to see if the water level float is stuck and move it a few times. If it alarms, it means that the water level switch is broken or the controller is broken.

  1. Over temperature alarm

Over-temperature alarm occurs. Generally, the current temperature is higher than the upper limit of the alarm value or lower than the lower limit of the alarm value. After an alarm occurs, first check whether the water temperature in the water tank is consistent with the temperature displayed by the temperature controller. If it is inconsistent, the controller or temperature control probe is faulty and needs to be replaced. If they are consistent, then observe whether it is an ultra-high temperature alarm or an ultra-low temperature alarm. The ultra-high temperature alarm is handled step by step according to the first troubleshooting method of the chiller not cooling, and the ultra-low temperature alarm is checked for the cooling conditions of the compressor to see if it is correct If there is a disconnection, there is no disconnection. The factory setting of the ultra-low temperature alarm set by the controller is 4 degrees, and the ultra-high temperature is 35 degrees. If the ambient temperature is higher than 35 degrees or lower than 4 degrees, an over temperature alarm will also appear.