Marine air conditioning plant is the key equipment of marine air conditioning system in the ship, which can deal the temperature and humidity of the air inside the chamber directly, has features of the new design, convenient operation, stable run, safety & reliable and easy maintenance, widely used for passenger ships, cargo ships, navies, and offshore platform, etc.
Attentions of installation
AC should be laid the wires as per the shipyard drawing and install as per the operation manual by a professional person.
The duct at the air inlet & outlet should be connected well to ensure no leak.
The installation location should leave sufficient space for commissioning and maintenance.
The water inlet & outlet pipe of the condenser should be connected as per the shown mark on the plant.
The water inlet & outlet pipe should be fitted with a valve for cleaning it.
AHU has a “U” type condensate water connection to ensure the water drain out thoroughly.
The checked items after installation
|Items to be checked||Accidents due to improper installation|
|Whether the installation is firm?||he plant may have some vibration or noise.|
|Whether the duct is installed well?||It wll cause insufficient cooling capacity(heating capacity).|
|Whether the conedensate outlet is fitted with “U” trap?||If condensate water can not drain out, fan motor will be burnt.|
|Whether the voltage comply with the nameplate?||The plant may have some malfunctions or parts damaged.|
|Whether the water inlet & outlet pipe of condenser connects correctly?||The plant can not work or have high pressure alarm.|
|Whether the cables comply with the drawings?||Cables will be burnt or the plant have malfunctions.|
|Whether safety valve outlet on condenser is connected to atmosphere?||Pollute chamber or result in personal injury|
Attentions of operation
Confirm the power supply wire is connected firmly, otherwise, it will cause electric shock or fire, don’t damage the wire or use another type of cable.
Ground: ground reliably, earth wire should be connected to the special ground device onboard.
Regulate the setting temperature to proper value.
A person is not permitted to stand on the plant or articles placed on it, otherwise, the plant will be damaged, the refrigerant will leak.
Don’t pour the water to AC or flush it by water, otherwise, it will result in malfunction or cause electric shock.
Notice for operation
When cooling, the compressor runs, the fan also runs, draw the inside hot air to AC box through the duct, the air will be cooled after passed through the evaporator and then sent to each room, just like this cycle, room temperature will be reduced.
When heating, the fan runs, draw the inside cold air to AC box through the duct, the air will be heated after passed through the heat exchanger and heater and then sent to each room, just like this cycle, the room temperature will be raised.
Unnormal working conditions of air handling unit(TMU)
When the ambient temperature is lower than 24℃, under “cooling” mode, if the compressor crankcase is not preheated, after runs, the plant may have an oil pressure alarm or compressor frost.
Start/stop instructions of compressor
To prolong the compressor life, under “auto” cooling mode, each start should wait 3-5min, and then the compressor will run. Under “manual” cooling mode, the compressor needs no wait and startup directly.
Main components name
Fan and motor
sea-water cooled Condenser
Operation method of marine centre air conditioning
The checked items before start-up
|The checked items||Accidents|
|Whether AC ventilation system is satisfactory?||The duct may have leak or clog.|
|Whether each room has sufficient ventilation flow?||The cooling(heating) capacity may be insufficient.|
|Whether steam flow valve is fitted with temp bulb?||Air outlet temp may be high and damage the plant.|
|Whether the cooling water flow is sufficient?||The plant has high pressure alarm and can not cool.|
|Whether AC cabinet is cleaned?||Fan may be clogged.|
|Whether the suction valve, discharge valve or liquid supply valve is opened?||Compressor is damaged or the plant can not run.|
|Whether the power is supplied?||The plant can not started.|
Provide the power supply
- Open electric box
2. Close the air switch.
Press the “fan start” button, the related lamp will be on and the fan will run.
Turn the mode switch to “ventilation”.
Press the “fan stop” button, the fan will stop running.
Press the “fan start” button, the fan will run.
Turn the mode switch to “heating”.
Open the steam inlet & outlet stop valve on the steam valve board.
Regulate the steam flow valve, air outlet temp should be controlled at 40℃±3℃.
Attention: for the first test the heating, air release valve above the heat exchanger should be opened, then close it after the air is release thoroughly.
Press the “fan start” button, the fan will run.
Turn the mode switch to “cooling”.
Temp controller is set at 24℃, capacity control temp controller is set at 26℃.
Turn the compressor selection switch to “auto”.
Turn the solenoid valve switch to “auto”.
The compressor will auto startup within 3min.
Press the “fan start” button, the fan will run.
Turn the mode switch to “cooling”.
Turn the compressor selection switch to “manual”.
Press the “compressor start” button, the compressor will run.
Turn the solenoid valve selection switch to “manual”.
Press the “compressor stop” button, the compressor will stop.
Attention: when startup during the cooling, if the ambient temp is lower than 24℃, preheat the crankcase for 1-2hour.
How to check the system leak?
- If the refrigerant is leaked thoroughly.
The needed materials and tools: the bottled nitrogen, relief valve, 5 long ¢6 copper tube, DN4 copper joint,short jumper, spanner, screwdriver,flare expand tool and sprinkling can.
Take φ6 copper tube, one end is welded to the outlet of the relief valve, the other end is sleeved with DN4 copper joint, then expand the flare. Remove the plastic cap and copper choke plug of the liquid charge valve, the relief valve is connected to the nitrogen bottle, and tighten it. Connect the copper tube with the relief valve, screw the DN4 copper joint of the copper tube on the liquid charge valve. Close the air switch, short connect terminals as per the electric drawing, then open the solenoid valve. Open the nitrogen bottle valve, regulate the outlet pressure at 1.5Mpa, then open the liquid valve, observe the high & low-pressure gauge till the pressure rises to 1.5MPa, close the nitrogen bottle valve and liquid valve. Use sprinkling can aim at all the connections, the leak place will have some bubbles.
2. If the refrigerant is not leaked thoroughly.
The needed material and tools: electric leak detector, spanner, and screwdriver
Open the electric leak detector, aim the probe at every joint, there will have an alarm sound at the leaking place.
How to vacuum?
The needed material and tools: vacuum pump, liquid pipe, spanner, and screwdriver.
The precondition of drawing the vacuum: the plant should pass through the pressure test and no leak. Screw off the plastic cap of liquid valve and cock of DN4 copper joint, connect the liquid pipe to liquid valve and vacuum pump, open all stop valves of the system and the vacuum pump, then open the liquid valve, close the liquid valve, and vacuum pump till the high & low-pressure gauge reaches to 720mmHg.
How to add the refrigerant?
The needed material and tools: bottled refrigerant, liquid pipe, short jumper, spanner, and screwdriver
Screw off the plastic casing of the low-pressure controller and short connect the two terminals, the liquid pipe will be connected to the refrigerant bottle valve and liquid valve, tighten the joint on the bottle valve, open it and discharge the air inside the liquid pipe, tighten the joint on the liquid valve, upside down the refrigerant bottle. Close the liquid outlet valve on the condenser, start up the compressor, open the liquid valve, the liquid refrigerant will enter into the system, the charge capacity is different due to different models, please refer to the following table. After the charge is fulfilled, stop the compressor, close the liquid valve and bottle valve, open the liquid outlet valve on the condenser, there should be no leak during the charging process.
|Air conditioning model||R22||R404A||R407C||R134A||Remark|
|CJKR-23||Kg charge capacity|
Compressor run pressure and alarm pressure
|run high pressure value|
|run low pressure value|
|protection high pressure value|
|protection low pressure value|
How to change the drier filter?
The needed material and tools: filter core, spanner, vacuum pump, liquid charge pipe, and electric leak detector
Startup the compressor and close the liquid outlet valve of the condenser, shut down after low-pressure alarm, then cut off the power supply. Open liquid charge valve, now there maybe have some refrigerant gas blow out, after release it, screw off seven combination screws on the cover of drier filter, draw out the core and change the new one, reinstall the core and screws, which should be tightened tightly. Liquid charge pipe is connected to liquid charge valve and vacuum pump, draw out the air from drier filter and piping, close the liquid charge valve and vacuum pump, open the liquid outlet valve of condenser, test by leak detector to ensure there is no leak.
How to add or change the oil?
The needed material and tools: oil, oilcan, clean towel, spanner, vacuum pump, and liquid charge pipe
How to add the oil?
Cut off the power and close the suction & discharge valve of the compressor, loose off the DN4 copper joint below the high & low-pressure controller, release the refrigerant inside the compressor, when the pressure gauge is displayed as zero, remove the oil charge bolt on the crankcase. Wipe the oil bottle accessories and oilcan with a towel, pour the oil into the can, the can nozzle should aim at the oil charge port of the compressor, observe the oil sight glass during the charging, when oil level reaches 2/3 of the sight glass, stop charging, reinstall the oil charge bolt and tighten the copper joint on the high & low-pressure controller. Now the compressor inside has some air and needs to draw the vacuum, there is fitted with DN4 stop valve between the copper pipes from oil pump outlet to oil pressure controller, loose off the copper joint with an oil pressure controller, one end of the liquid charge pipe is connected to the stop valve and vacuum pump, open the pump, when the pressure reaches to 720mmHg, close the stop valve, remove the vacuum pump and liquid charge pipe, recover, tighten and open the suction and discharge valve of the compressor.
Change the oil.
Cut off the power and close the suction & discharge valve of the compressor, loose off the DN4 copper joint below the high & low-pressure controller, release the refrigerant inside the compressor, when the pressure gauge is displayed as zero, remove the oil drain bolt nearby the crankcase heater accessory, tighten it after oil is drained out. Remove the oil charge bolt above the crankcase, the oil charge method is the same as that of the oil add(refer to the above “how to add the oil”).
Note: different compressors and refrigerants use a different oil when add or change, please use the same specification oil.
How to disassemble the solenoid valve?
The needed material and tools: vacuum pump, short jumper, spanner, internal box spanner, and screwdriver.
Short connect the two terminals of the low-pressure controller, close the power of AC, close the liquid outlet valve of the condenser, start up the compressor, when the pressure reaches to 0MPa, the compressor will stop. Close the suction valve of the compressor, pry off the solenoid valve coil with “-” screwdriver, screw off the four screws with box spanner, take off the solenoid valve stem, you can see the core, the lower part of the core is nylon, which will be stuck by some foreign material(scraps and welding slag) and make the valve closed not tightly. Reinstall the screws, the system needs to draw the vacuum, please refer to “how to draw the vacuum”, then open the liquid outlet valve of the condenser and compressor suction valve.
You can see the expansion valve after opening the access door, regulate it as per the above method.
How to regulate the temp controller?
The temperature controller divides into the start/stop temp controller and capacity control, temp controller. The start/stop temp controller can control the start/stop of the compressor, the temp controller has a temp scale and knob switch, the set value is 24℃; the capacity control temp controller is to control the capacity of the compressor, the set value is 26℃.
How to regulate the steam flow valve?
The valve can control the flow of steam to control the high or low air outlet temp, there has a degree scale on the regulation stem, regulate the air outlet temp as per the scale.
Cut off the power of AC, close the water inlet & outlet valve of condenser, screw off the water drain valve of the condenser to discharge all water, lose all the SS bolts on both sides of the condenser to remove the cover, then you can see a copper tube, use a soft brush to stretch into the tube and drag back and forth to clean it. Each piece should be cleaned thoroughly, including the disassembled cover. When reinstall, pay attention to the direction of cover and cushion, and don’t damage the cushion. Clean the condenser 2-3 times every year.
Seawater piping should be installed with a sea strainer, the hole should be less than 2mm. If the plant will stop for a long time, close the inlet & outlet valve of the condenser and drain out the inside water thoroughly. For the first start, open the cooling water pump, close the outlet valve of the condenser, then open the valve slowly to regulate the water flow and make a high-pressure gauge at 1.5Mpa, then regulate the water flow and make high-pressure gauge at 1.3Mpa-1.4Mpa, make a mark on the water outlet valve or remove the adjustable wheel to prevent regulate the value arbitrarily. If there has much change due to the ambient temp, regulate the outlet valve slightly.
Air filter mesh maintenance
There has a maintenance door on the AC cabinet for cleaning the filter mesh, open it, you will see the handle of filter frame, draw it out, the filter mesh has several pieces, everyone can be disassembled and flush it with clean water, its pressure should be not too large to prevent damaging the mesh, reinstall it after dried.
Maintenance times: 2-3 times every month.
Check the fan belt’s tension or whether it is damaged, change it in the schedule. Check the motor bearing, measure the temp, in summer it should be not more than ℃, in winter it should be not more than ℃, add the lubrication oil from the oil charge nozzle.
Maintenance times: 1-2 times every month.
After AC is run for a time, the unit will have some rust, customer should be cleaned frequently, repair the damaged paint.
Maintenance times: 1-2 times every year.
When AC is running, record the run data once an hour, it is good to check the run condition and can prolong the AC life.
|compressor low pressure||compressor high pressure||air outlet temp||oil level|
Malfunction: open air switch, the power indication lamp is off.
Removal:open the electric box, measure the voltage of terminals L1, L2 and L3 with multimeter, if it is zero, the total power should be supplied by customer, if it has some voltage, the power may have wrong phase sequence or lack phase, then check the LED lamp on power monitor,if voltage is over or under, customer should check the total power,if phase sequence is wrong, exchange the wiring of L1 and L2.
Removal: cut off the power, disassemble the cover of fuse, measure the fuse resistance with multimeter, if it is zero, the fuse is good, if the resistance is infinite, the fuse is bad, change a new one.
Malfunction: water pressure alarm
Removal: water pressure alarm value is set at 0.07Mpa, the reset value is 0.12Mpa, if water pressure is lower than 0.07Mpa, the plant will give out water pressure alarm, open the water inlet & outlet valve of the condenser and make the water pressure reach to 0.12Mpa, the plant will auto-reset to normal.
Malfunction: oil pressure differential alarm
|oil pump||A3 “|
If the oil viscosity is big, when startup the compressor, it will enter into the system with the refrigerant, the oil level will reduce, oil pressure differential alarm, it is normal. Oil viscosity is affected by temperature, in spring or autumn, the viscosity will be big and preheat it before start-up; start up the fan and select “cooling” mode, turn compressor button to “manual”, now the crankcase heater is opened, heat it about 1hour till the temperature reaches to 40±5℃. The open-angle of the expansion valve will also affect the oil pressure, if opened too big, the oil level will reduce and oil pressure alarm, regulate the expansion valve flow(refer to “how to regulate the expansion valve”), after running for a time, the oil will return to the compressor, the oil level will rise and recovery.
If the compressor has run for a long time, the oil may be color changed or dirt, if not change in time, the oil pump will be clogged and oil pressure will be reduced, the plant will give out oil pressure differential alarm. Close the suction & discharge valve of the compressor, screw off the DN4 copper joint below the high & low-pressure controller connection to release the refrigerant gas inside the compressor, remove the oil drain plug on oil pump suction, draw out the oil strainer and clean it after the oil is drained thoroughly. Reinstall the oil drain plug and add oil for the compressor, please refer to “how to change the compressor oil”.
The inside parts of oil pump may be destroyed, disassemble the oil pump and make a check, change the new pump if have the same specification.
Note: when the plant has an oil pressure differential alarm, remove it and needs a manual reset alarm, press the reset button on it to reset after 3min of the alarm.
Malfunction: high pressure alarm
|water valve piping||B2|
Open the compressor suction valve and condenser liquid valve fully, if it is not opened fully, compressor high pressure will be high and result in high-pressure alarm.
Open the condenser inlet & outlet valve to ensure sufficient water flowing into the condenser, if the nearby water is too dirty, clean the cooling water piping of AC thoroughly.
If AC has run for a long time, the inside water pipe of the condenser will be dirt and needs to clean, please refer to “how to clean the condenser”.
The charge capacity is different for each model AC, if charged too much, compressor high pressure will be too high and result in a high-pressure alarm, please refer to “refrigerant charge capacity table” to drain redundant refrigerant.
Malufnction: low pressure alarm
|expansion valve solenoid valve||C4|
Open the compressor suction valve and condenser stop valve fully, the open-angle will affect compressor suction pressure and result in a low-pressure alarm.
As per the above ” compressor run pressure and protection pressure”, if the system lacks refrigerant, the run pressure of compressor will reduce and result in compressor low pressure alarm. Now it should check the system leak, please refer to the chapter “how to check the system leak” and make an overall check of the whole plant, for add the refrigerant, please refer to “how to add the refrigerant”.
The oil dirty and foreign material of the system will be attached on the drier filter mesh, please refer to the chapter”how to change the drier filter” to disassemble the filter and clean the mesh.
If the temp bulb of the expansion valve is broken, the compressor will shut down due to a low-pressure alarm, check the temp bulb, please refer to “how to change the expansion valve” to change a new one. There have two kinds of conditions about the damage of expansion valve: one is that solenoid valve coil is damaged, as per the electric drawing, find the terminal of solenoid valve coil, measure the resistance of coil with a multimeter if the coil is burnt, change new one; the other is that solenoid valve base is clogged inside, please refer to “how to disassemble the solenoid valve” to clean the inside dirty.
If the temperature controller is set too low, the compressor can not shut down with long term run and result in low-pressure alarm, regulate the temp controller and set at 24℃.
Note: low pressure alarm needs no manual reset, after low pressure rises to 0.4Mpa, controller will auto reset.
Malfunction: overheat alarm
Regulate the expansion valve and increase the refrigerant flow, please refer to the chapter “how to regulate the expansion valve”. If the expansion valve is opened too small, no sufficient refrigerant returns to the compressor, which will cause too high compressor suction temperature and discharge temperature and result in overheating alarm.
Add refrigerant, please refer to “how to add refrigerant”.If the system lacks refrigerant, the suction temperature of the compressor will be high and discharge temperature will be high too and result in an overheat alarm.
The compressor inside problem: wear too much, high-pressure cavity or low-pressure cavity has air colluded, repair the compressor, please contact us and repair by professional man, don’t open the compressor by customer yourself.
Malfunction: overload alarm
|Over current protector||E1|
Change new over-current protector, if it is used for a long time, the inside elements will be aging and cause wrong alarm.
Change new contactor, if it is used for a long time, inner contact will wear too much and make bad contact, so it will make the voltage unstable, current large, and over the current alarm.
The compressor inside is clogged, the motor coil may be destroyed, please contact with us and repair by professional person and don’t open the compressor by customer yourself.
Malfunction: compressor frost without low pressure alarm
|compressor suction valve||F1|
|air inlet & outlet flow||F2|
|air filter mesh||F3|
Open the suction valve of the compressor thoroughly.
Regulate the return air damper and room diffuser to ensure sufficient air inlet and outlet flow. If the airflow is small, the refrigeration capacity around the evaporator surface can not be brought out, the refrigerant inside the evaporator can not evaporate efficiently, some liquid refrigerant will be back compressor and cause frosting or liquid shock.
Clean the air filter mesh, please refer to the chapter “air filter mesh clean”.
Regulate the expansion valve and reduce the refrigerant flow, please refer to the chapter “how to regulate the expansion valve”.
Add refrigerant, please refer to “how to add refrigerant”.If the system lacks refrigerant, the suction pressure of the compressor will reduce, evaporation temp will reduce either, the temperature of the suction connection will reduce and frost.
Malfunction: it can not humidify
|steam needle valve||G2|
|humidify solenoid valve||G3 “|
Regulate the button on humidity controller, set at 70%, if the setting value is too small, the ambient humidity will be larger than the setting one, humidity controller will auto close the humidify solenoid valve and can not humidity.
Open the steam needle valve.
Use an internal hexagonal wrench to remove the screws on humidify solenoid valve body, check the core whether it is clogged, if yes, it will cause that the plant can not humidify.