Depending on the outcomes of a comprehensive check-up on your chiller, some or all of the followings may apply;
⦁ Compressor(s) overhauling
⦁ Retubing or tube-plugging on evaporator/condenser depending on the Eddy Current test results.
⦁ Condenser cleaning (chemical + mechanical: applies only for water-cooled chillers) or condenser coil cleaning (only for air-cooled chillers)
⦁ Condenser replacement (partial or complete: applies only for air-cooled chillers)
⦁ Oil replacement based on wide-spectrum oil analysis.
⦁ Refrigerant recovery and optimum charge: on each circuit, existing refrigerant shall be recovered and filtered. Following the proper sequence of actions, refrigerant recharging shall be performed based on factory charge amounts.
⦁ Chiller controller corrective actions: problems in the control modules shall be either fixed where possible by servicing or replaced with a new one otherwise.

Depending on the annual operation span of the chillers and on the ability of the technical team in your facilities, the most suitable annual preventive maintenance program shall be developed. Frequency and the content of the agreement shall be mutually decided. Such program shall include some or all of the following content:

a. Content of the Main Maintenance Visit (comprehensive season-opening maintenance visit)

⦁ Control of the electrical cables and components
⦁ Cleaning of the control panels
⦁ Control and maintenance of contactors
⦁ Motor winding insulation control (megger)
⦁ Control of safety equipment
⦁ Control of parameters and settings
⦁ Visual and mechanical control
⦁ Gas (refrigerant) leakage control
⦁ Oil sample collection, oil analysis, and report issuance via a 3rd party internationally accredited analysis institute. The report shall be issued together with the recommended corrective actions list if exists any.
⦁ Oil filter replacement (if needed)
⦁ Drier core replacement (if needed)
⦁ Control of the evaporator line flow switch
⦁ Control of the condenser line flow switch (applies for water-cooled chiller only)
⦁ Water flow rate control
⦁ Start-up of chiller
⦁ Operating parameters control
⦁ Chiller efficiency control
⦁ Condenser cleanliness and air resistance control (applies for air-cooled chiller only)
⦁ Fans operation and balance control (applies for air-cooled chiller only)

b. Content of the Intermediate Maintenance Visit (midseason maintenance visit)

⦁ Control of the electrical cables and components
⦁ Motor winding insulation control (megger)
⦁ Control and maintenance of contactors
⦁ Control of safety devices
⦁ Control of parameters and settings
⦁ Fans operation and balance control (applies for air-cooled chiller only)
⦁ Cleaning of the control panels
⦁ Gas (refrigerant) leakage control
⦁ Water leak control
⦁ Visual and mechanical control
⦁ Water flow rate(s) control
⦁ Control of the evaporator line flow switch
⦁ Control of the condenser line flow switch (applies for water-cooled chiller only)
⦁ Start-up of chiller
⦁ Operating parameters control

c. Content of Season Closing Maintenance Visit

⦁ Control of the electrical cables and components
⦁ Motor winding insulation control (megger)
⦁ Control and maintenance of contactors
⦁ Control of safety equipment
⦁ Control of parameters and settings
⦁ Fans operation and balance control (applies for air-cooled chiller only)
⦁ Cleaning of the control panels
⦁ Gas (refrigerant) leakage control
⦁ Water leak control
⦁ Visual and mechanical control
⦁ Water flow rate control
⦁ Control of the evaporator line flow switch
⦁ Control of the condenser line flow switch (applies for water-cooled chiller only)
⦁ Operating parameters control
⦁ Shut down of the chillers (with existing frost protection system on and associated electrical heaters being kept open)

Comprehensive maintenance contracts are all-inclusive that gives peace of mind to the owners as well as FM companies. Some benefits are as follows;

• Provides you with a reliable chilled water system through comprehensive maintenance coverage including preventive maintenance and other planned maintenance activities that are customized as a result of a thorough analysis of your chillers and chilled water system.  
• Minimizes undesired/unexpected downtimes and fix on failures therefore related losses.  
• Keeps your chillers at the best possible operating conditions and provides you with a highly energy-efficient operation. 
• Lets your technical team focus on their other key activities.  

• All these are brought to you at a reasonable predetermined and firmly budgeted cost. 

This type of contract requires a pre-contract thorough inspection. Based on this inspection report there may be some repairs that need to be done before a comprehensive coverage contract.

This type of service is provided based on an emergency call from the equipment owner. We follow the following procedure:

⦁ Conduct a comprehensive failure diagnostics on the chiller
⦁ Determine the corrective actions for diagnosed problems
⦁ Mutually agree (by a contract) on the corrective actions
⦁ Apply the corrective actions
⦁ Commission the unit

Chemical and mechanical cleaning shall be applied via the following procedure;
⦁ The right chemical formula shall be selected, making sure that it is active to the undesired scale inside the tubes.
⦁ Chemical shall contain the right type and rate of inhibitor that it is not active to the metal surfaces.
⦁ The chemical concentration shall be at a very safe level, and the cleaning shall be repeated as many as required until there is no scale left.
⦁ Following the chemical cleaning, tubes are rinsed by freshwater.
⦁ Following the rinsing, the loosen residuals of scale shall be removed utilizing the brushing machine.

⦁ Eddy Current testing is crucial preventive maintenance that should be applied to all tubes of evaporator and condenser to identify risk-bearing tubes. This will allow taking action to eliminate the risk of tube failure. If a tube fails, water leaks into the refrigerant circuit, and consequently a complete chiller failure will happen which will cost nearing to a new chiller. Why does a chiller HX tube fail?

⦁ Aggressive water use in an open condenser circuit (usually this happens unintentionally and can`t be avoided if your open type cooling tower is subject to an air stream of acidic environment. Acidic content eventually reaches the condenser tubes and erode them by the time.
⦁ If the cooling tower feed water hardness is lower than the recommended level then it becomes active to all metal surfaces.
⦁ If the cooling tower feed water hardness is much higher than required a considerable scale builds up inside the tubes. Following the chemical and mechanical cleaning, it is unclear whether there is some damaged spots or weak spots under the scale. This is called under scale corrosion which is dangerous as the tube cleaning service will remove the scale and corroded spots will be exposed even leaks. Although tube cleaning when performed carefully does not damage tubes, in such situations tube leaks are unavoidable.
⦁ Particles especially metal ones passing through a bad strainer may also damage tubes.
⦁ If already some tubes are leaking, the other potential leakage candidates must be determined. The severity of the situation must be known to determine whether the problem could be solved by the elimination of a certain percentage of the tubes or the complete replacement of the tubes are needed.

⦁ This test is a non-destructive test that is applied by insertion of a probe into the complete span of each tube on the heat exchanger
⦁ Eddy Current test is not a leak detection method. It will show the general condition of the HX to take further actions if necessary.

Based on the Eddy Current test results either of the following corrective actions is applicable:
⦁ If the number of defective tubes(i.e over 40% metal loss) is less than 10% of the total number of tubes on any pass of the heat exchanger, then the elimination of these defective tubes by plugging possible.
⦁ If the number of defective tubes is more than 10% of the total number of tubes on any pass of the HX then tube replacement (retubing) becomes the right solution.

These are the main reasons why a comprehensive oil analysis should be done on the compressor oil for each refrigerant circuit;
⦁ It provides very reliable indications on; the wear and tear of condenser/evaporator/compressor(via the metal content levels)
⦁ Water content (which may mean several different problems like poor evacuation or leak)
⦁ Whether the oil is to be replaced or not (acidity level, viscosity level, contamination, etc)

Depending on a.m. indications following actions and results might be applicable:
⦁ Further investigation on condenser/evaporator/compressor which may lead to proper corrective actions and prevent further costly damages.
⦁ Refrigerant refinement (or alternately replacement), deep evacuation refrigerant charge at factory specifications. This would not only protect your chiller but also let it run at maximum capability with minimum power input.
⦁ Unnecessary and costly oil replacement might be avoided.

⦁ The thermal camera provides the surface temperature map of compressor sections, condenser sections, power panels, cables, etc.
⦁ With this tool, combined with vast expertise we can pinpoint potential problems. It also helps to make root cause analysis.
⦁ This service not only improves the quality of diagnostics but also reduces the downtime via service time improvement.

⦁ It is applied externally on a bare pipe surface. The position of measurement should have a fully developed laminar flow. Therefore it should be located at least 5 diameters away from any valve/elbow etc.
⦁ Actual water flow rates over evaporator and condenser are not only crucial parameters of chiller performance but also might directly indicate some important problems.
⦁ It shows whether the design flow rates are realized or not. If some divergence is detected, the root cause can be determined and proper corrective action could be applied.
⦁ If there is less flow than the design figures, and at the same time pumps are running free of problems, these indicate a flow restriction in the water circulation circuit:
⦁ Size of the pipelines (i.e: intended flow rate and the diameter of the pipeline should be proportional to yield a frictional resistance of not more than 20mmWg/1000mm)
⦁ Size of all flow control valves, strainers, etc.
⦁ Position of valves
⦁ Status of strainers (mesh size/dirt accumulation rate)
⦁ The functionality of check valves
⦁ Evaporator and Condenser: when the measured flow rate / measured pressure drop / are used on the characteristic pressure differential vs. flow rate curve of the specific heat exchanger, it would indicate whether the heat exchanger is clogged or the problem is embedded in the pipeline instead.
⦁ If there is more flow than the design figures, and at the same time pumps are running free of problems, these indicate a flow regulation needs in the water circulation circuit.
⦁ Pumps: if the pumps are equipped with frequency inverters, the upper limit frequency can be assigned.
⦁ Pipeline: If the pipeline has a flow regulation valve, this valve can be adjusted.

⦁ We conduct an efficiency analysis on your chiller to determine it`s actual efficiency compared with its original efficiency based on design operating conditions.
⦁ The more your chiller run closer to its original efficiency conditions, the less power consumption shall be.
⦁ Parameters of efficiency analysis are as follows:
⦁ Below figures shall be tabulated at the same time under different cooling load % and different ambient air conditions.
⦁ Flow rates over both evaporator and condenser
⦁ Inlet and outlet temperatures on both
⦁ Outdoor ambient conditions (dry bulb/ wet bulb)
⦁ Cooling tower inlet/outlet water temperatures
⦁ Compressor current draw or KW consumption
⦁ System feed/return water temperatures
⦁ System feed flow rates
⦁ Calculated figures from measured parameters shall be as follows:
⦁ Cooling tower performance curve
⦁ Chiller performance curve
⦁ System demand curve
⦁ We submit a comprehensive report with diagnostics and possible corrective actions.
⦁ Deviations from design conditions shall be listed.
⦁ The reasons for and the corrective actions shall be reported.
⦁ The benefits and payback of the corrective actions shall be indicated in the report.