CPU unit To control the airconditioning , transmission of air conditioning system 3 0.033 Miniature circuit breaker To protect the equipment from excessive current 18 0.02 Magnetic contactor To open / close the power circuit for a compressor 12 0.033 Relay For equipment protection 153 0.033 AVR To change the voltage of DC power supply for 3 0.2 Switch/display panel To select mode of air conditioning and to indicate the state of air conditioning unit 3 0.2 Total estimated man-hours required for corrective maintenance per year per 3 car train: 63.2man-hour /1000000 hr 35 Preventive maintenance Ventilation and air conditioning is considered as one of the major sub-systems on a rolling stock that the performance will affect passenger safety and comfort. Maintenance activities described in this section apply to the whole subsystem and are grouped in accordance with maintenance cycle. The
maintenance planner can group the activities to work orders to fit rolling stock maintenance windows and available resources. 36 Overview Ventilation and air conditioning system consists of the following major components: • Air conditioning unit (ACU) • Cab air handling unit (CAHU) • Air conditioning control panel (ACCP) Two self-contained roof-mounted SACU are provided on each car. A CAHU is provided separately in the Mc car to feed the cooling air from the main air conditioning duct system to the driver’s cab. CAHU can control the cooling air volume by using manual switch. The ACU is equipped with two fully enclosed horizontal type screw compressors. In the event of an interruption to the traction supply, the evaporator fans in the ACUs shall continue to operate from the battery supply for a period of over 60 minutes after the supply is interrupted. One Air Conditioning Control Panel (ACCP) is installed in each car saloon cabinet. The ACCP controls the operation of two ACUs installed per car with input feedback from a return air temperature sensor, and also the temperature set / operation command from the Train Control & Monitoring System (TCMS). As shown in Figure 1, the refrigerating cycles consist of compressors, condenser coils, filterdriers, capillary tubes, evaporator coil, accumulators, high / lowpressure switches, and service valves. Copper tube connects these components forming a hermetic circuit. The refrigerant flow progresses as follows:
1. The refrigerant is compressed into a high-temperature / high-pressure gas by the compressor. 2. The high-temperature / high-pressure refrigerant gas enters the condenser coil, where it is cooled / condensate to a liquid by the ambient air supplied from the condenser fan. 3. The high-pressure liquid refrigerant flows to the capillary tubes through a filterdryer. Any moisture in the refrigerant is removed in the filter-dryer. 4. The liquid refrigerant is decompressed by capillary tubes and is turned into low-pressure liquid; it goes into the evaporator. 5. The heat of mixture air (return and fresh) supplied by the evaporator fan is absorbed due to the evaporation of the liquid refrigerant. The refrigerant turns back into a gas in the process. The cooled air resulting of the heat absorbing is supplied to the interior of the car. 6. Superheated refrigerant gas returns to the compressors through an accumulator. Any remaining liquid refrigerant returning to the compressors is caught in the accumulator and the gas is allowed to return to the compressor. 7. The cycle is then repeated. 8. The fresh and return air is dehumidified as it moves through the evaporator coil.
Figure 1 – Refrigerating circuit diagram I
Figure 3 – Air conditioning unit overview -2 Figure 4 – Air conditioning unit overview -3
Figure 5 – Air conditioning system 37 Preventive maintenance plan The air conditioning units are designed for high reliability and easy maintenance. The re-charge and re-adjust of refrigerant pressure and lubrication oil volume are not necessary since the refrigerating circuit has no leakage and is a fully hermetic type. The frame and cover is stainless steel so no painting is required. Since there is no refrigerant leakage, it is not required to fill the circuit with refrigerant in the life span of the air conditioning unit. 38 Procedures & checklist Notes: Safety preconditions and precautions, including the requirement of personal protection equipment, shall be provided for each preventive maintenance task to ensure safety to personnel.
39 Air Conditioning Unit (ACU) In order to avoid unpleasant smell in the system, it is required to conduct wash and spray untimold solution to the ACU annually. Spray application process shall be conducted after cleaning process of each part of ACU. 1 Washing Air Conditioning Unit from the roof. 1. To prevent electrical shock, disconnect Stinger and turn Main Switch to Isolate. 2. To prevent electrical shock, switch off Power Box in both Mc1 and Mc2 3. Move a movable scaffold to the place where scaffold work area is fit for ACU 4. Lock the movable scaffold.
5. Hook a harness on scaffold in correct position in the corner on the scaffold. 1 safety harness can be hooked on each corner. Maximum 4 persons are arrowed to stay on each side of scaffold. 6. Protect electric parts with water proof sheet from washing water except for Evaporator Coil and Water Drip Tray. 7. Wash Evaporator Coil and Water Drip Tray using the hot and high pressure water machine.
8. Clean other area in ACU by using wet clothes with neutral detergent, e.g. Lipon-F dilutions by water. Wipe off the detergent with the clean wet cloth. 9. Check if all Area are properly clean, if not clean more. 10. Dry inside of ACU. 2 Applying NOKIF to ACU from the roof. ① Apply NOKIF 5 dilutions by water to mainly Evaporator Coil, Water Drip Tray, the cover of ACU and overall ACU. The recommended volume of the spray is 31 litters per car, use NOKIF 6.2 litters. ② Re-install Return Air Filter on Evaporator Coil and the cover of ACU.
4.3.1.1 Condenser coil 1. Remove the outside cover. 2. The area except for condenser coil where marked with red colour area shall be necessary for water tightness. 3. Remove the hard dust on the surface using the vacuum cleaner and soft brush. 4. Use a vacuum cleaner to clean the surface of the condenser coil. 5. Clean between fins using the pressurised water or steam. After cleaning, be sure to clean the water drain route and the inside of drain pipe using the pressurised water or steam. 6. Check the deformation of fins. Repair, if necessary. 7. If dirt between fins cannot be cleaned out, replace the condenser coil. I
4.3.1.2 Evaporator coil 1. Remove the inside cover. 2. Air filters are removed from the unit. 3. The area except for evaporator coil where marked with red colour area shall be necessary for water tightness. 4. Remove the return air filter on evaporator coil. 5. Remove the hard dust on the surface using the vacuum cleaner and soft brush. 6. Clean between fins using the pressurised water or steam. After cleaning, be sure to clean the water drain route and the inside of drain pipe using the pressurised water or steam. 7. Check the deformation of fins. Repair, if necessary. 8. If dirt between fins cannot be cleaned out, replace the evaporator coil. 4.3.1.3 Connection duct 1. Check dirt / sand are piled up on the surface. 2. Remove dirt and sand using pressurized air and vacuum cleaner. 3. Check the deformation and clack which affect the water tightness. 4.3.1.4 Resilient rubber of compressor
1. Remove the outside cover. 2. Check the outside view. Exchange to new one, if crack, deterioration, etc. is found. 3. Lift the compressor without breaking piping in replacing the resilient rubber. 4. Check to make sure the compressor operation noise / vibration is normal. Figure 7 – Resilient rubber for compressor 4.3.1.5 Resilient mount for ACU 1. Check the outside view. 2. If crack, deterioration, etc. is found, lift the air conditioning unit and replace the resilient rubber. 4.3.1.6 Main frame 1. Clean the main frame with pressurised water or steam using a soft brush. 2. Check the surface. Repair by welding, if crack, etc. is found
3. If repaired portion is in the water tight area, carry out the water tight test. 4.3.1.7 Cover 1. Clean the outside surface of cover with pressurised water using a soft brush. 2. Check the outside view. Repair by welding, if crack, etc. is found 3. Check the thermal insulator and sealing rubber. Repair or replace if crack, deterioration, etc. is found. 4. If damage such as irreparable crack, etc. is detected, replace the cover with a new one. 4.3.1.8 Water drain route 1. Remove the inside cover. 2. Check dirt / sand are piled up in the water drip tray, the drain water route. 3. Remove the scattering prevention cover and check dirt / sand are piled up at surrounding of drain hole. 4. Remove dust and sand in the water drip tray. Water drip tray Scattering prevention cover Figure 9 – Water drain route 4.3.1.9 Piping for refrigerating circuit
1. Check piping, if area or piping surface showing accumulation of oil is found. Both refrigerant and oil are spout out from leak portion. 2. Using the leak detector for R-407C or soapy water, check to make sure there is no leaked position. 3. If a leaked position is found, repair the leaked position using a brazing kit. 4.3.1.10 Wiring 1. Check insulation resistance between wiring and frame. Refer to clause 4.3.1.11. 2. Search extreme deformation, acute angle bending and expansion of sheath. 3. Exchange the wiring to new one, if failed wiring is found. 4.3.1.11 Insulation resistance check 1. Connect the short circuit connector for CN1 and CN2 as belows. Short circuit connector for CN1 Short circuit connector for CN2 2. Disconnect the control circuit of 24 V or less and emergency inverter for emergency.
3. Change magnetic contactor to closed position. (IVK, EFK1, EFK2, EFK3, EFK4) 4. Short the transformer terminals. 24 24
5. Short circuit the main circuit line (CN1). 6. Short circuit the control circuit line (CN2). 7. Measure following insulation resistances with 1000 V insulation resistance meter. 7-1) Between short circuit connector for CN1(Main circuit) and frame 7-2) Between short circuit connector for CN2(Control circuit) and frame 7-3) Between short circuit connector for CN1(Main circuit) and short circuit connector for CN2(Control circuit) Insulation Resistance Allowable Value Main circuit - Frame More than 5MΩ Control circuit - Frame More than 2MΩ Main – Control circuit More than 5MΩ
8 4.3.1.12 Condenser fan 1. Remove the outside cover. 2. Check dirt / sand are piled up on the surface of propeller fan and base plate 3. Remove dust using vacuum cleaner and wetted dust cloth. 4. Disconnect electric connector and measure wire resistance. 5. Check for unusual noise and vibration. 6. Repaint, if necessary. Figure 10 – Condenser fan 4.3.1.13 Evaporator fan 1. Remove the inside cover. 2. Check dirt / sand are piled up on the surface of casing and motor. 3. Remove dust using vacuum cleaner 4. Open terminal box and measure wire resistance. 5. Check for unusual noise and vibration. 6. Check dirt is accumulated at the inside of blades.
7. Remove dust using wetted cloth. Figure 11 – Evaporator fan 4.3.1.14 Multi-blade fan of evaporator fan cleaning 1. Loosen and remove M8 bolts fixed the inside cover. 2. Detach the inside cover. 3. Loosen and remove M5 screw fixed the terminal cover of evaporator fan motor and detach the terminal cover. Figure 12 – EF Terminal
4. Record the wiring number and terminal position to prevent the wrong work for reassemble 5. Loosen and remove 6-M8 bolts fixing the base plate of evaporator fan and 2-M6 bolts fixing the fan casing. Figure 13 – EF mounting bolt location 6. Remove the evaporator fan from air conditioning unit and transport it to the adequate work space for washing by using the adequate jigs such as the crane. 7. Loosen six M6 bolts and remove the outside inlet ring at the opposite side of motor. M8 bolt Fan casing M6 bolt Connecting Duct
Figure 14 – EF outside inlet ring 8. Loosen the M16 nut at the end of motor shaft which fix the fan wheel. Store the fan wheel and M16 nut for reuse. 9. Wheel rotation direction and screw directions of M16 nut for No.1 and No.2 evaporator fan are different. Please attach the mark or store separately. 10.Pull up the fan wheel toward you. 11.If fan wheel and shaft is adhered by something like as grease/dust, please use a pulley extractor. Figure 15 – EF motor shaft
12.Prepare the large bucket which can dip the whole fan wheel. 13.Pour water into the bucket, and dissolve the neutral detergent or the sodium bicarbonate. 14.Dip the whole fan wheel in the above mentioned liquid for approximately 120 minutes. 15.(The dipping time is changed by the adherence state of dust.) Figure 16 – Fan wheel dipped in the bucket 16.Wipe off the dust which is accumulated at the inside of blade by using the soft blush which is used for car washing. 17.After removal of dust, courteously wash the fan wheel using the clean water to remove the chemical agent. 18.Wipe off the remained water and dry the fan wheel. 19.Make the fan wheel up from the reverse way of disassembly. 20.Reinstall the evaporator fan and reconnect the wiring according the record.
4.3.1.15 Emergency inverter 1. Remove the inside cover. 2. Check dirt / sand are piled up on the surface of inverter. 3. Remove dust using vacuum cleaner 4. Remove inverter with an installation board. 5. Check the unusual state such as the burn marks, deformation, etc. 6. Replace to new one, if unusual state is detected. Figure 17 – Emergency inverter 4.3.1.16 Transformer 1. Remove the inside cover and the cover for transformer. 2. Check dirt / sand are piled up on transformer. 3. Remove dust using pressurized air and /or neutral detergent, e.g. Lipon-F. 4. Check the rust and corrosion. 5. Remove rust and repaint, if necessary. 6. Replace to new one, if state is severe condition.
Figure 18 – Transformer 4.3.1.17 Electric parts box Following electric parts are installed in this box. 1) Magnetic contactor for emergency inverter 2) Magnetic contactor for evaporator fan 3) Over current relay for compressor 4) Over current relay for evaporator fan 5) AVR for smoke detector 6)Relay for smoke detector 7)Relay for emergency damper 1. Remove the inside cover. 2. Remove the cover for electric parts box. 3. Check dirt / sand are piled up on the inside of electric parts box and the surface of parts.
4. Remove dirt and sand using pressurized air and vacuum cleaner Figure 19 – Electronic parts box 4.3.1.18 Fresh / return air damper 1. Remove the inside cover. 2. Check dirt / sand are piled up on the surface of damper and surrounding of motor axis. 3. Remove dirt and sand using pressurized air, vacuum cleaner and wetted dust cloth. Figure 20 – Fresh & Return air temperature sensor 4.3.1.19 Temperature sensor for return air 1. Remove the inside cover. (
2. Check dirt / sand are piled up on the copper tube of sensor. 3. Remove dirt using the wetted dust cloth. 4.3.1.20 Temperature thermostat for aux. control 1. Remove the inside cover. 2. Check dirt / sand are piled up on the thermostat. 3. Remove dirt and sand using pressurized air and vacuum cleaner 4.3.1.21 Emergency damper 1. Remove the inside cover. 2. Check dirt / sand are piled up on the surface of damper and surrounding of motor axis. 3. Remove dirt and sand using pressurized air, vacuum cleaner and wetted dust cloth. Figure 21 – Emergency Damper Geared motor (Inside of box)
4.3.1.22 Smoke detector 1. Remove the outside cover. 2. Remove the cover for smoke detector box. Figure 22 – Smoke detector cover 3. Check if dusts are piled up on the surface of detector and surrounding. If yes, remove dusts using pressurized air and vacuum cleaner. 4. Remove dusts of the filter in the cover for smoke detector box using either of followings: Pressurized air Vacuum cleaner Figure 23 – Smoke detector cover & air filter
5. Remove the smoke detector with the mounting plate. Note: There are four (4) flat washers, φ11.5 - t1.5, between the smoke detector mounting plate and the mounting base. Make sure not to lose these washers during the work. Figure 24 – Smoke detector & mounting plate 6. Turn the sensor portion to the direction of arrow, and remove sensor portion from sensor body. Smoke detector
Figure 25 – Smoke detector 7. Install the smoke detector and surrounding parts in the manner of the reverse order of the above procedure after the maintenance work. Figure 26 – Smoke detector reinstalled (Sample from Mc1 ACU1) 4.3.1.23 Temperature sensor for fresh air (Please refer to Figure 3 regarding location) 1. Remove the outside cover. 2. Check dirt / sand are piled up on the copper tube of sensor. 3. Remove dirt using the wetted dust cloth. 4.3.1.24 Pin layout of electric connector
Figure 27 – Pin layout for electric connector
4.3.1.25 Return Air Filter This maintenance work performed from passenger room. 1) Return air filter 1. Set ACU to “STOP” mode of TCMS 2. Open the maintenance hatch of ceiling. 3. Turn the latch bolts and open the fresh/return air damper plate for maintenance 4. Push filter to upper, pull up the bottom side of filter and pull out in front. 5. Install new filter or washed filter (*) by reverse procedure for removing. 2) Fresh air filter 1. Carry out the work 1)-1 to 1)-3. 2. Filter is fixed at bottom of main frame. Loosen and remove bolts. 3. Pull out the fresh air filter below. 4. Install new filter or washed filter (*) by reverse procedure for removing. Figure 28 – Return and Fresh air filter
Note (*): Wash air filters by following procedures: - a) Dip filters in hot water, 80 deg.C or more, with baking soda. b) Rinse filters with hot & high pressurized water machine. c) Use of racks for wash and drying air filters at open air is recommended.
Air Conditioning Control Panel 1. Remove cover. 2. Check dirt / sand are piled up on the copper tube of sensor. 3. Remove dirt using the vacuum cleaner and pressurized air. CN5 Figure 30 – Outline of ACCP
Submission No. RST-4507 Rev. 09 for ACU2 Noise filter is installed under Switch/Display panel Figure 31 – Switch/Display panel
Submission No. RST-4507 Rev. 09 Figure 32 – Location of MCB, MC, LVD and Timer relay ( 11) ( 12) ( ( 22) ( 11) ( 12) ( 21) ( 22)
Figure 33 – Location of Relay
Figure 34 – Electric connector (CN1.2) Pin layout
Figure 35 – Electric connector (CN3, 4) & Terminal block Pin layout
40 Cab Air Handling Unit Earth stud (M6) Figure 36 –Outline of CAHU 4.3.3.1 Fan 1. Remove ceiling panel. (Please refer to the car structure maintenance manual for the removal method.) 2. Remove maintenance cover of CAHU by release of the catch-clip. 3. Check dirt / sand are piled up on the surface of propeller fan 4. Remove dust using vacuum cleaner and wetted dust cloth. 5. Disconnect electric connector and measure wire resistance.
6. Check for unusual noise and vibration. 7. Repaint, if necessary. 4.3.3.2 Damper 1. Remove the ceiling panel. (Please refer to the car structure maintenance manual for the removal method.) 2. Remove maintenance cover of CAHU by release of the catch-clip. 3. Check dirt / sand are piled up on the surface of damper and surrounding of motor axis. 4. Remove dirt and sand using pressurized air, vacuum cleaner and wetted dust cloth. Figure 37 – Damper 4.3.3.3 Electric Parts Box Following electric parts are installed in this box and are attached to box. 1)Two magnetic contactors and over current relay for fan 2)Four relay for supply airflow rate controls 3)Electric connector for AC 400V circuit
4)Electric connector for DC 100V circuit 5)Electric connector for fans 6)Electric connector for damper 1. Remove the ceiling panel. (Please refer to the car structure maintenance manual for the removal method.) 2. Remove maintenance cover of CAHU by release of the catch-clip. 3. Remove the electric connector and cover for electric parts box. 4. Check dirt / sand are piled up on the inside of electric parts box and surface of electric parts. 5. Remove dust using compressed air, vacuum cleaner and wetted dust cloth. Figure 38 – Electric parts box
4.3.3.4 Indication Lamp 1. Operate CAHU using the mode select switch of cab. 2. Check the green indication lamp turns on. 3. Remove dust using compressed air, vacuum cleaner and wetted dust cloth. 4.3.3.5 Pin layout of electric connector Figure 39 – Pin layout of electric connector
4.3.3.6 Operation mode and associated equipment Mode Equipment VF 1 VF 2 DAMPER OFF OFF OFF Open LOW ON OFF Open MID ON ON Close HIGH ON ON Open
41 Corrective maintenance 42 Overview Corrective maintenance is performed at unpredictable intervals because the fault time of a component is not known in advance. The objective of corrective maintenance is to restore the system to a satisfactory operational condition and within the shortest possible time after fault. A fault is the inability of a component or system to fulfil its functional requirements, leading to a state that may have an impact on operations or service. Equipment fault can be a sustained or an intermittent fault. Sustained fault is easier to identify and easier to isolate, while intermittent fault is irregular symptoms and therefore harder to diagnose. It is necessary to identify the cause of fault, such as processes that are the basic reason for fault or which initiate the process by which deterioration proceeds to fault. The effect of fault could have impact on the operation, function or status of an item. Fault effects are usually classified according to how the entire system is impacted. By defining the possible level of impact, appropriate corrective maintenance actions shall apply. 43 Scheduled repair Hard time replacement is included in preventive maintenance. 44 Unscheduled repair Each car is equipped with two air conditioning units. Main parts of air conditioning unit and control panel are divided into two parts to prevent the loss of cooling capacity per car exceeds more than 25% by one part fault. Unscheduled repair is minimal.
45 System recovery procedures The system recovery on ventilation and air conditioning system is based on the identifying and replacing Line Replaceable Unit (LRU) concept to minimise the equipment down time and to recover the services as soon as practicable. A LRU is a modular piece of equipment, within a major assembly, that can be removed for repair and replaced quickly. The following sections describe the guidelines and procedures on how to isolate, diagnosis, identify and replace the defective LRU. 46 Fault isolation/diagnostics Fault parts and related parts for ventilation and air conditioning unit can be switched off directly or by using CPU via fault relay. 47 Flow chart of fault diagnostics Please refer to Figure 34 when maintenance technicians approach the fault isolations and diagnostics.
Figure 41 – Flow chart of fault isolation/diagnostic
48 Outline and function of control equipment for ACCP and ACU Following section shows the function of control equipment of ACCP and ACU. Before attempting the fault isolation and diagnostic, please read and understand the function of control equipment for the rapidly solve. 49 Outline/Function of protection devices for ACU and ACCP Followings are outline of protection devices installed in ACU and ACCP. Electromagnetic contactor is not protection device. Since fault is able to detect by using own auxiliary contact, electromagnetic contactor is shown in this paragraph. 5.4.1.1 For normal operation As for the relationship between the protection devices, related control relay and the stopped parts, please refer to Table 15. Activations of almost protection devices are transferred to ACCP using relay for fault. If this relay breaks down, there is a possibility of fault as well as of fault due to the protection device occurs 1. Miniature circuit breaker (MCB) (ACB11, 12, 21, 22 in ACCP) MCB protects the air-conditioning unit from overload and short circuit. When a MCB is tripped, lockout occurs. CPU can detect the state of MCB by using auxiliary contact of MCB. 2. Electromagnetic contactor (EFK1, 2 in ACU and CFCPK11, 12, 21, 22 in ACCP) Electromagnetic contactor fault is detected by using its own auxiliary contact.
CPU can detect the fault of electromagnetic contactor (CFCPK11, 12, 21, 22) by using the auxiliary contact of CFCPK. Related relay (EF11FR, EF12FR, EF21FR, EF22FR) informs the fault of electromagnetic contactor EFK1, 2 to CPU by opening contact No.5-9. Automatic retry is performed at the time of fault. Lockout of EFK will occur in the third round of fault after repeated twice automatic retry. 3. Over current relay (EFOCR1, 2, CPOCR1, 2 in ACU) Over current relay in the main circuit for compressors and evaporator fans operates when motor is overloaded. Related relay for fault (EF11FR, EF12FR, EF21FR, EF22FR) informs the activation of EFOCR to CPU by opening contact No. 5-9. Related relay for fault (LPR11, 12, 21, 22) informs the activation of CPOCR to CPU by opening contact No.5-9, and turn off CFCPK by opening contact No.6-10. Automatic retry is performed at the time of fault. Lockout of evaporator fan will occur in the third round of fault after repeated twice automatic retry. Lockout of compressor will occur in the third round of fault after repeated twice automatic retry or fault state continues for 30 minutes. 4. Inner over load relay (IOL1, 2, CF1Th, CF2Th in ACU)
Inner over load relay is a kind of thermostat relay and it is embedded in the motor winding of compressor and condenser fan. This thermostat operates when the heavy load of motor heats the motor winding. Related relay for fault (LPR 11, 12, 21, 22) informs the activation of IOL or CFTh to CPU by opening contact No.5-9, and turn off CFCPK by opening contact No.6-10. Automatic retry is performed at the time of fault. Lockout of compressor will occur in the third round of fault after repeated twice automatic retry or fault state continues for 30 minutes. 5. High pressure switch (HPS1, 2 in ACU) The high pressure switch is a pressure shut-off switch and connected to the refrigerating circuit by copper pipe. It operates when the refrigerating circuits is at unusual high pressure. Related relay for fault (HPR 11, 12, 21, 22) informs the activation of HPS to CPU by opening contact No.5-9, and turn off CFCPK by opening contact No.6-10. Automatic retry is performed at the time of fault. Lockout of compressor will occur in 99th round of fault after repeated 98 automatic retry. 6. Low pressure switch (LPS1, 2 in ACU)
The low pressure switch is a pressure shut-off switch and connected to the refrigerating circuit by copper pipe. It operates when the refrigerating circuits is at unusual low pressure. Related relay for fault (LPR 11, 12, 21, 22) informs the activation of LPS to CPU by opening contact No.5-9, and turn off CFCPK by opening contact No.6-10. . Automatic retry is performed at the time of fault. Lockout of compressor will occur in the third round of fault after repeated twice automatic retry or fault state continues for 30 minutes. 5.4.1.2 For emergency ventilation Following items are protection devices which are used in the event of emergency ventilation mode. 1. Miniature circuit breaker (MCB) (IVCB in ACCP) MCB protects the air-conditioning unit from overload and short circuit. When a MCB is tripped, lockout occurs. CPU detects the state of MCB by using auxiliary contact. 2. Electromagnetic contactor (IVK, EFK 3, EFK 4 in ACU) Electromagnetic contactor fault is detected by using its own auxiliary contact.
Related relay for fault (IVFR) informs the fault of IVK detected by auxiliary contact of IVK to CPU by opening contact No.5-9. Related relay for fault (EFFR) informs the fault of EFK 3, 4 detected by auxiliary contact of EFK3, 4 to CPU by opening contact No.5-9 Automatic retry is performed at the time of fault. Lockout of emergency ventilation system will occur in the third round of fault after repeated twice automatic retry. 3. Over current relay (EFOCR 1, 2 in ACU) Over current relays of evaporator fans for emergency ventilation are same as normal ventilation. Related relay for fault (EFFR) informs the activation of EFOCR to CPU by opening contact No.5-9. Automatic retry is performed at the time of fault. Lockout of emergency ventilation system will occur in the third round of fault after repeated twice automatic retry or fault state continues for 30 minutes. 4. Protection system of inverter Inverter fault is detected by using the installed protection system answer back signal. Related relay for fault (IVFR) informs the fault of inverter to CPU by opening contact No.5-9. Automatic retry is performed at the time of fault.