Author Archives: Maximus Chillers

Chiller Condenser Retrofitting

Chiller Condenser Retrofitting

We recently undertook the job of having a bespoke 'V' chiller condenser retrofitted for a customer of ours in the North West

Rusted and Corroded Condenser

The old condenser looked alright on the surface- the fins were in good condition. The chiller condenser was 18 years old, however and when an attempt to repair a leak had been carried out- the condenser would leak further along. This is because of the warming rusted and corroded copper with an oxy-acetylene torch

Chiller Condenser Retrofitting

Our supplier arrived on site to measure up for the job. The ‘V’ chiller condenser being retrofitted was built to order. Exact replicas were made to the same specifications and sizes of the old ones. The operating pressures and high pressure cut out limit were taken into account in the design and the use of materials

0161 370 7193

service@maximuschillers.com

Contact Form

Lift Out of Chiller Condenser being Retrofitted

On the day of the lift and shift we isolated the panel and checked it was dead, then we removed the panel and laid it on it’s front. This was to access the rivets behind the panel. These rivets, the ones on the other end of the chiller and around the lid had to be ground off with an angle grinder. The fans were disconnected and removed to make the lid lighter to lift off. Then, we attached slings to the chiller condenser and lifted both halves of the 'V' out

Lift In of the Chiller Condenser being Retrofitted

This part we did not want to get wrong as the chiller condenser being retrofitted was brand new and did not have a mark on it. A reverse of the removal- it fitted perfectly just the same as the old one. With the lid lifted back on and the fans in- time for brazing then the pressure test

Pressure Test, Dehydration and Recharge

The pressure test was satisfactory so our engineer put the system on vac for dehydration purposes and the removal of non condensables. After a deep vacuum was achieved the system was recharged and run tested. No issues were found

Read more about air cooled condensers at the Institute of Refrigeration Click Here


Carrier Chiller Service in Moscow

Carrier Chiller Service

Category : chiller service

 

Our customer in Moscow had been emailing our technical support desk regarding the service of his Carrier chillers

Flow Issues

There had been ongoing issues with blocked strainers on the water system. Each time they were cleaned, they blocked back up again. A large dirt trap near to the chiller also needed to be repeatedly cleaned out. A problem with dirt being carried round the water system

Flush Out Service for the Carrier Chillers

The end user had employed a local company for a flush out service for the Carrier Chillers. The company first drained the water system and refilled it with various chemicals. There is a chemical to lift the dirt off the inside of the pipe. Another chemical to carry it back. Another chemical to bond with the heavier elements

Carrier Chiller Service Readings

The readings taken during the Carrier chiller service were wrong by a long shot. There was a serious restriction in flow to the chiller. Safety devices were activated on the chiller to prevent system failure. If not for these safety devices- the chiller would be ruined. More than one device was preventing the chiller from freeze up

0161 370 7193

service@maximuschillers.com

Contact Form

Service of the Water System

The water system was drained down to service the plant. The inlet to the evaporator was removed for inspection. A Considerable amount of sludge was found to be blocking the inlet to the evaporator. The pipe was bolted back on, the water system was refilled then emptied in the reverse direction to the water flow. The water system was filled again and system readings taken

Service to the Carrier Chiller

The service to the Carrier Chiller was found to be satisfactory as the water system readings were okay. No safety devices were being activated and a good run was achieved from the Carrier chiller. All other readings were taken as part of giving the chiller a full heath check. As always a detailed Tick Sheet was completed. Our engineer demonstrated to the on site engineers how to back flush should the issue arise again

Read about legionella and how it can affect a chilled water system on Wikipedia 


Industrial Refrigeration Ammonia Service Cat Ladder

Industrial Refrigeration Ammonia Service

Industrial Refrigeration Ammonia Service Visit

The industrial refrigeration ammonia service visit was in Aberystwyth. We look after 2 ammonia chillers on site. They are 10 year old chillers that have been designed to need ongoing service. Quite easy job as the faults they go into are reoccurring round in a circle. They have previously had the same problems

Shaft Seal for Industrial Refrigeration Ammonia Service

The industrial refrigeration shaft seal had started to leak so ammonia service was arranged. It was fitted by removing the shaft seal cover, splitting the coupling and sliding the shaft seal over the shaft. After removing the non condensables, we reintroduced the ammonia back into the compressor. The 'o' rings leaked

Ammonia Service of Leaking Industrial Refrigeration 'O' Rings

The ammonia service of industrial refrigeration ‘o’ rings occurs because they become flattened and plastic like. This is caused by heat around the high side of the screw compressor. When there is pressure in the system- the oil if forced against the gap- making a seal. After the ammonia refrigerant had been handled- the oil ran away- causing the leak when the ammonia was reintroduced

0161 370 7193

service@maximuschillers.com

Contact Form

Lift and Shift for Ammonia Service Visit

Before the ammonia service visit, the compressor had been removed of it’s pipework and ancillaries. The lift and shift guys arrived and set up their lifting equipment. They raised the compressor and manoeuvred it on to a trolley. They used a stair walker to get it up and down the steps. They used a winch to get the compressor, end on- down a cat ladder

Tear Down if the Ammonia Screw Compressor

It is always better to tear down this kind of compressor in a workshop- on a bench with compressed air and all the tools nearby. We unbolted the castings and slid the screw out. The various castings being laid out in a line. We replaced the ‘o’ rings for new the rebuilt the compressor

Ammonia Refrigerant Charging
Ammonia Refrigerant Charging

Ammonia Refrigerant Service Charge

Part of the ammonia refrigerant had been handled during the service visit. This left the compressor pipework, compressor and the oil separator open to atmosphere. The non condensables were evacuated. In the photo we are lifting the cylinder up a cat ladder into the plant room. From there it needed to be man handled up some steps, down some steps and out onto the roof. We charged the ammonia plant with liquid ammonia until the superheat and subcooling values were within industry known limits. The sight glass levels and condition were monitored too

If you would like to buy an introduction to ammonia refrigeration from the iiar Click Here


Chilled Water System Repair

Chilled Water System Repair of Condenser

Chilled Water System Condenser Beyond Repair

The condenser on the chilled water system had been deemed to be beyond repair by the customer. The previous company had been chasing leaks round in a circle so the customer had decided to buy a new condenser. This was our first job with a new Maintenance Contract so we wanted to make a good impression

Condenser Removal on the Chilled Water System

There was no refrigerant in the chilled water system so our engineer cut the discharge and liquid line to the condenser. He then drilled out the rivets so the frame could be taken apart. Lifting shackles were fitted to the old condenser to aid the removal. Then, slings were fitted and a forklift truck removed the old condenser

Condenser Replacement on the Chilled Water System

Our engineer supervised the condenser replacement on the chilled water system. He found that the new condenser did not fit correctly. The new condenser was 5mm thicker than the old one. It was decided to lift it back out and angle grind the frame to make more room. Once this was completed, the new condenser fitted correctly and was bolted in place

Chilled Water System Pipework Repair

The pipework had to be repaired and brazed in on the chilled water system. Then, the standard practice of a pressure test to ensure the integrity of the system

The Evacuation Process

Having passed the pressure test, our engineer set up the vac pump and started the evacuation process. This is to dehydrate the system by pulling a vacuum of less than 2 Torr. Any moisture in the system will boil away and leave the system dry

Recharge and Test Operation

The refrigerant is R410a. Our engineer put around half the charge in, then trimmed the remaining charge according to the superheat and subcooling values. He monitored the chilled water system for the rest of the day. He was looking for leaks as the plant was at operating pressures of 30 Bar. All was well, so the customer signed off the paperwork as he was pleased with the efficient professionalism of our engineer

Read more about air cooled condenser installation at the Institute of Refrigeration Click Here


Chilled Water System Service near Saint Basil's Cathedral

Global Chilled Water System Service

Moscow Visit

Always good to get out of the country to carry out chilled water system service around the globe. Just had a little free time this visit to see Red Square and Saint Basil's Cathedral. Most of the visit was bogged down resolving issues

Electrical Problems

One of the water cooled chillers was pumping down due to electrical problems. One of the solenoids for the evaporator was not opening. All checked out okay with the solenoid coil and valve. Following the wiring diagram lead to the relay board. The relay board is responsible to run various components around the compressor. It was not obviously blown and there were no dry soldered joints on the back. I decided to tighten up the wiring and unplug, then plug all the connectors back in. When I ran the chiller again the problem went away

Chilled Water System Global Service

As we provide a global service for chilled water systems: we cannot get back the day after leaving site. Therefore, after resolving the above issue, I ran the system in local with some of the other systems off to prove it. All was okay. After completing the rest of the service on the chillers I put the whole of the plant back in Auto to prove it all together

0161 370 7193

service@maximuschillers.com

Contact Form

Flow Switch Failure During Global Chilled Water System Service

The flow switch failed in one of the most remote plant rooms in the globe for chilled water system service. This is due to security issues. As one of the service checks- I tried to trip the chiller on flow fail. The chiller did not stop. I didn't want to valve off the water system repeatedly as the air handlers are old and 'dead heading' could cause failure. Instead I decided to use the Hand/ Off/ Auto switch for the pump. There are two adjusting screws on the flow switch. After several attempts I got it to settle down, then carried out tests to make sure it would not happen again

Read More industry news on the Refcom website

 


Chilled Water System Flow Switch Maintenance

Chilled Water System Maintenance

Maintenance of the Chilled Water System Flow Switch

The chilled water system flow switch requires regular maintenance due to a to build up of contaminants on the sensor. Over time, slime accumulates giving false readings. The problem is relatively easy to sort out: a wipe with a cloth

Retrieving the sensor

The more difficult part is deciding how the retrieve the sensor. It is fixed with a bolt into the chilled water system being maintained. Therefore there is pressure inside. The textbook way to do the job is to valve off the section of pipework, then drain the glycol into a vessel. There are other ways known to an engineer

Snatching the Flow Switch!

Although not text book: snatching the flow switch is a considerably easier way of maintaining the chilled water system! One of our seasoned engineers unscrewed the bolt whilst holding the flow switch in. He whipped it out- gave it a quick wipe and stuck it back in! Only a small amount of the secondary coolant was lost (which shot out- loosing no height) He re-tightened the bolt and the job was done

0161 370 7193

service@maximuschillers.com

Contact Form

Checking the Fault Out Level

As you can see from the picture: there is a green light on 0. This indicates that the pump is off. Not to be confused with pressure, as there will be a couple of bar on a roof an 6 bar or so in a basement. The higher pressure in a basement is due to the head of water pushing down. With the pump on: the green lights go all the way up to 9 with the fault out level showing red on 7

Maintaining the Chilled Water System Fault Out Level

Maintaining the chilled water system flow switch can be achieved with a terminal driver. Using the manual that comes with the flow switch: the buttons can pressed a number of times to 'self test' Also, the fault out level can be set

Testing the Flow Switch

As part of the maintenance, the flow switch is manually tested using one of two methods. This ensures that the switch will function correctly when it needs to

Read more about flow measurement on Wikipedia


Chilled Water System EEV Service

Chilled Water System Service of EEV

The Expansion Valve Required Chilled Water System Service

Chilled water system service was being carried out because the mechanical parts of the expansion valve had failed. This particular valve is prone to this fault. It is an OEM part so our technician found the voltage for the motor and found a similar part with the same amount of steps

Electronic EEV Driver

The EEV driver was found to be functioning satisfactorily. Sometimes, depending on how the mechanical part has failed, this can be overloaded and burned out

Electronic Component Refurbishment

Where electronic parts, such as the EEV driver, are found to be burned out- Maximus Chillers has a refurbishment laboratory at head office. We have the capability to strip down the component and fault find where it has blown. Usually it is quite simple: the jammed mechanical part of the electronic expansion valve has burned out the power control on the driver for example. More complex fault finding and component replacement on the circuit board can be carried out also. Another option is to replace the driver with a like for like swap or retrofit to a different driver. In any case- we have the ability for: any part- any problem- any refrigerant anywhere

0161 370 7193

service@maximuschillers.com

Contact Form

Pump Down of the Chilled Water System

The chilled water system was easily valved off and pumped down. This saves on the time and recovery vessel to pump the refrigerant out

Remove and Replace

Once pumped down, our engineer removed and replaced the valve, sealing it on it's knife edge seal. The wire was passed up the conduit and into the panel. The wiring colour scheme was different on the new valve so some time was taken to ensure it was wired up correctly

Open it up and Switch it on

After leak testing, the refrigerant system valves were opened back up and the plant switched back on. The correct superheat and subcooling valued were achieved concluding a successful chilled water system service visit

To read the Institute of Refrigeration guide to expansion valves Click Here


Industrial Refrigeration Oil Service

Industrial Refrigeration Oil Service

Industrial Refrigeration Oil Service

An industrial refrigeration oil service visit was arranged because of an oil return issue. Several fans had been down on the air cooled chilled water system. This causes the chilled water system to unload so as to prevent a fault occurring. The lower mass flow rate of the refrigerant caused oil to migrate to the low side of the system. Several vessels are available with various forms oil return control. These vessels were valved off. A two man team with the correct ammonia PPE and breathing apparatus carried out the job

Not Enough Oil Recovered During Service to the Industrial Refrigeration Plant

Only some of the oil was recovered using during the industrial refrigeration service of the plant. Therefore, the engineers decided to add new oil to get the chilled water system running. The only problem with doing this is that once running the machine, the oil has to be got back out. Therefore, the industrial refrigeration oil service had to be carried out a second time to resolve the oil return issue

0161 370 7193

service@maximuschillers.com

Contact Form

Industrial Refrigeration Service by Fitting Fan Decks

For this industrial refrigeration service visit, scaffolding had been erected in accordance with the Risk Assessment. The old fan decks were lifted out by the two man team. A really good team was sent out: one of the men was more technical and the other more mechanical- complementing each other with their different skill sets. The new fans were an updated version and the wiring was different. The fault link had to be adapted but the 0-10v input from the controller was the same. The controller reads the pressure from a transducer, then sends out a voltage which the fan turns into the corresponding speed

Service Testing of the Industrial Refrigeration System

The fault link had been correctly modified, so service testing of the industrial refrigeration system was carried out. The machine loaded up to 62% and monitoring continued during the rest of the visit

Read More about International Institute of Ammonia Refrigeration Technology and Standards

 


Service to Industrial Refrigeration Controller

Industrial Refrigeration Service Visit

Tick Sheet for the Industrial Refrigeration Service Visit

The industrial refrigeration service visit is carried out inside a walk in room so some of the machine can be serviced in the dry. Good job because it is a bit of a rainy day- don't want to get the tick sheet wet!

Chiller Controller

The controller for the plant has been problematic from when the chiller was first lifted in. It faults out regularly: reoccurring known faults known to the customer. Part of the problem are low load conditions. This causes the chiller to go into various alerts then it eventually trips out

Over Complicated Program for the PLC

Another part of the problem are over complicated controls. I often think about the same machine in a critical process environment. This machine is bespoke so there will be a bog standard version as well. The controls on this version have too many sensors, generating too many faults. There is always something which trips it out when no fault as such is present. The controls themselves are a fault if they are problematic. Factory Managers don't like too many industrial refrigeration service visits because of spurious trip outs- they just want the plant to just run seamlessly. This customer, however, has to pay for more parts and more industrial refrigeration service is to keep it running

0161 370 7193

service@maximuschillers.com

Contact Form

Trim the Ammonia Refrigerant

The chiller has a low refrigerant charge so an industrial refrigeration service visit has been arranged to trim the ammonia refrigerant. We have state of the art ammonia refrigerant recovery units Read More but these are used when handling tonnes of ammonia refrigerant. This is just a small 200kw industrial refrigeration plant so we will be using a smaller ammonia refrigerant recovery method

Oil Return During the Industrial Refrigeration Service Visit

Low refrigerant charge diagnosed during the industrial refrigeration service visit causing the oil to migrate to the low side of the system. The oil will need to be manually recovered from various vessels following the ammonia oil recovery procedure

Read more about events from the iiar Click Here


Chiller Evaporator after Service

Water Chiller Service of Evaporator

Service to Water Chiller Shell of Evaporator

Not often does water chiller service to chiller evaporator fault occur. Usually the evaporator has frozen up and burst the tubes inside the shell. This fault involved the shell of the chilled water system itself bursting. On close inspection- the shell was made out of thin steel- not the usual heavy rolled steel. It looked like the near end on the photo had sagged down, causing the evaporator shell to buckle

Replacement of Evaporator

This option would be expensive due to the cost of the evaporator. It would be a difficult  visit because of access issues. The builders decided to site the water chillers round the back of the building. This makes glycol chillers very difficult to service. A dedicated lift and shift company would be needed to get the old chiller evaporator out and the new on in. There is a difficult corner to get round where the evaporator would have to be tilted up to get it round. Also, a fence wound have to be taken down around the chillers. Of course security is an issue but so is chilled water system service to glycol chillers and air cooled chillers

0161 370 7193

service@maximuschillers.com

Contact Form

Water Chiller Service with Silver Solder

Because of the above it was decided by the customer to attempt water chiller service using silver solder. The Risk Assessment Method Statement allowed for the chilled water system service to be carried out with a half hour fire watch. The oxy-acetylene lines were leak tested prior to the job. Both leaks were soldered up but despite the evaporator being drained down, there was still water and steam trying to get out. Not the best water chiller service soldering resulted- but it held

Air Cooled Chiller Paintwork

Because air cooled chillers are usually outside- the chiller paintwork is essential. Poor water chiller service of paintwork will reduce the it's life. After preparing the surface, direct to rust paint was applied so as to protect it for the future

Lagging Service for Glycol Chiller

The main purpose of Armour Flex lagging is to reduce heat gain from the environment to the water chiller being serviced. This provides protection from the elements for the glycol water chiller as well

See the Institute of Refrigeration Evaporator efficiency Click Here

 


Translate