Contents 1. GENERAL SPECIFICATIONS NOMENCLATURE LT SERIES SPECIFICATIONS APPLICATION LIMITS...

Transcription

1 Contents 1. GENERAL SPECIFICATIONS NOMENCLATURE LT SERIES SPECIFICATIONS APPLICATION LIMITS CONSTRUCTION & FUNCTIONS DESIGN FEATURES CAPACITY MODULATION Step-type Control Stepless Type Control The Positions of Solenoid Valves COMPRESSOR UNLOADING FOR STARTUP, AND STOP LUBRICANT LUBRICANT TABLE OIL CHARGING OIL CHANGE Change Oil Periodically: Pre-cautions of Changing Oil SYSTEM APPLICATION PIPING DESIGN Suction and Discharge Piping Layout Economizer Piping Layout Minimum Pressure Valve Liquid Line Filter Dryer Sight Glass with Moisture Indicator OIL LINE Oil Supply Lubrication and Capacity Control Modulation Liquid Injection to Chamber System Protection in Oil Line Oil Cooling System LIQUID INJECTION TO MOTOR ECONOMIZER SYSTEM Economizer Application Sub Cooler Flash Tank EXAMPLE OF SYSTEM LAYOUT... 31

2 6. MOTOR DESIGN MOTOR PARAMETERS AND DESIGN Y-Δ Start Power source requirement MCC&LRA Terminal cover plate Terminal box COMPRESSOR INSTALLATION OPEN COMPRESSOR WOODEN CRATE COMPRESSOR LIFTING COMPRESSOR INSTALLATION OPERATION AND MAINTENANCE COMPRESSOR COMMISSIONING CHECK Check list before Start up Check list during operation TROUBLE SHOUTING TABLE DIMENSIONS ACCESSORIES ACCESSORY LIST ACCESSORY FOR GAS REFRIGERANT LINE Stop valve Flange bushing Check valve Minimum pressure valve OIL LINE ACCESSORY Oil flow switch External oil filter Oil line solenoid valve Oil pressure differential switch ELECTRICAL ACCESSORY INT-69HBY motor protector Pt100 temperature controller W Oil heater OTHER ACCESSORY Mounting pad PERFORMANCE R R404A

3 1. General A single stage screw compressor can achieve -40 ~-50 as the lowest SST (saturated suction temperature). If SST -60 ~-65 is required, a compound two stage compressor or multi unit of single stage compressors are necessary. Multi unit of single stage compressors can be applied in low temperature application, but the system control is more complicated and they occupy more space. In low temperature application such as 60 ~-65, a compound two stage compressor is a better choice. In this kind of high pressure ratio condition, the compound two stage compressor has better performance in internal leakage (compression efficiency), high discharge temperature and reliability. With more than 20 years of experience in design and manufacturing screw compressors, Hanbell launched compound two stage screw compressors LT series compressors which have two types: LT-S series (semi-hermetic type) and LT-G series (open-type) to meet customers need. The LT series compressors can be applied in the high pressure ratio environment, such as frozen products, tunnel freezers, cold storage, industrial cooling, process cooling, heat-pump applications, etc. 1

4 Displacement m 3 /h 2. Specifications 2.1 Nomenclature Note: LT-G is dedicated to R717 Figure LT Series LT-20/10 LT-30/12 LT-41/20 LT-62/20 LT-83/41 LT-128/41 LT-235/83 Figure 2. Note: 1) Developed model:lt-20/12, LT-30/12, LT-83/41 2) Under-developed model:lt-41/20;lt-62/20;lt-128/41;lt-235/83 2

5 2.3 Specifications Model Low Stage Hi Stage Displacement Rated Speed 50/60Hz 50Hz 50Hz rpm Vi (Low Stage) Descriptions Vi (High Stage) Capacity Control (Step type: ST) (Stepless type: SL) Lubrication Type Noise Level m 3 /h m 3 /h ST SL db LT-20/ %/50% 100% 10% Pressure LT-30/ ~ differential 100% LT-83/ Model Weight 3550 LT-S LT-S-H LT-G 10%/50% 75%/100 % Motor Type Starting Voltage Insulation Protection 85 Pressure Test Kg Kg Kg bar LT-20/ / 560 LT-30/ / phase 2 pole Y-D 380 Class F PTC + PT LT-83/ Figure 3. 3

6 2.4 Application Limits Figure 4. 4

7 R404A Figure 5 5

8 3. Construction & Functions 3.1 Design Features 1) Unloading-type slide valve in high stage Patented unloading-type slide valve is in high stage of LT compressors. It s no need to install additional external parts and unloading-type slide valve can work mechanically. This design makes the compressor work under minimum load easily and effectively. 2) Built-in suction check valve The built-in suction check valve saves installation space for customers convenience. 3) Optimal motor cooling path Excellent design of the motor cooling path cools down the motor coil reliably and efficiently even under serious working condition. 4) Built-in filter for economizer The built-in filter for economizer provides further protection to compressor and makes the system layout simpler. 6

9 3.2 Capacity Modulation The capacity modulation of LT series compressors has step type (3-step / 4-step) and stepless type. Both of these two different capacity modulations work with the slide valve, piston rod, cylinder, and piston. When the slide valve is at the suction side completely, the screw rotors work with full displacement under full load. When the slide valve moves to the discharge side, the bypass occurs between the slide valve and the suction side then the displacement and cooling capacity decrease. The lubricant comes from the external oil separator and passes through the oil filter then enters into the oil inlet port of the compressor. The lubricant of the two path ways enters into the cylinder and high-pressure lubricant flows out to the suction side by energizing the solenoid valve to make piston move then the slide valve moves as well. Because of the moving of the slide valve, volume of compressed refrigerant will increase or decrease to achieve capacity modulation. The purpose of the piston spring is to push the piston to the initial position (min. load position). It not only alleviates the mechanical impact on compressor moving parts, but also reduces the electrical current during compressor start up. Figure 6 7

10 3.2.1 Step-type Control 1) Step-type table Y: Energize the solenoid valve N: Do not energize the solenoid valve LT-83/41 SV1: (NC) SV2:10% (NC) SV3:50% (NC) SV4:75% (NC) SV5:100% (NC) 100% N N N N Y 75% Y N N Y N 50% Y N Y N N 10% (Start/Stop) Y Y N N N LT-20/10 &30/12 SV1: (NC) SV2:10% (NC) SV3:50% (NC) / SV5:100% (NC) 100% N N N / Y 50% Y N Y / N 10% (Start/Stop) Y Y N / N Table 1 2) Description of Step-type control 10% load 8 Figure 7 When starting up the compressor, SV1(unloading) & SV2 (10%) need to be energized to make the piston keep at the 10% position(left side) Under this situation, the high pressure oil passes through SV1 then goes to the right side of the piston. At the same time, the oil in left side of the piston passes through SV2 (10%)

11 then going out to the low pressure side. In doing so, the piston can be held at the 10% position. Note: 10% load is for start up only. Running the compressor at 10% load for a long time is not recommended. 50% load Figure 8 Under 50% load, SV1&SV3 (50%) need to be energized. Under this situation, the high pressure oil passes to the left side of the piston continuously. At the same time, the oil passes through SV1 then goes to the right side of the piston. If the piston position is at the left side of the 50% hole (the loading is lower than 50%), the oil in the right side of the piston will pass through SV3 (50%) and go out to the low pressure side then the piston will move to right side until the position of 50% hole. It s called loading to the 50% position. Vice versa, if the piston position is at the right side of the 50% hole (the loading is higher than 50%), the oil in the left side of the piston will pass through SV3 (50%) and go out to the low pressure side then the piston will move to left until the position of 50% hole. It s called unloading to the 50% position. 9

12 75% load Figure 9 Under 75% load, SV1&SV4 (75%) need to be energized. The logic of 75% load is similar to those of 50%. The piston can be held at the 75% position by 75% hole to make the compressor run under 75% position. 100% load Figure 10 Under 100% load, SV5 (100%) needs to be energized. Under this situation, the high pressure oil passes to the left side of the piston continuously. At the same time, the oil in the right side of the piston passes through SV5 (100%) then goes to the low pressure side to make the piston be held at 100% position. 10

13 3) The control of the water temperature with step type Start Condensing water temp. Set point + 2T Set point + T Stop Set point Set point T' 10% 50% 75% 1~3 min t1 t2 100% 75% 50% 10% 60~90 sec Time Figure 11 Note: T & T' should be adjusted by system designer s experience and practical application Stepless Type Control 1) Stepless-type table Y: Energize the solenoid valve N: Do not energize the solenoid valve SV1: (NC) SV2:10% (NC) SV5:100% (NC) Loading N N Y Unloading Y Y N Holding N N N 10% load (Start/Stop) Y Y N Table 2 2) Description of Stepless-type control In stepless type control, the oil keeps going to the left side of the piston. The oil bypass in the left side of the piston is controlled by SV2 (10%). The oil charging in the right side of 11

14 the piston is controlled by SV1 and oil bypass in the right side of the piston is controlled by SV5 (100%). These three solenoid valves are controlled by temperature controller or PLC. Loading Figure 12 The SV5 (100%) needs to be energized and the high pressure oil goes into the left side of the piston continuously and the oil in the right side of the piston bypasses through SV5 (100%) to the low pressure side. The piston moves to the right side and the compressor load increases. Unloading Figure 13 12

15 The SV1 & SV2(10%) need to be energized and the high pressure oil passes through SV1 and goes into the right side of the piston continuously. At the same time, the oil in the left side of piston bypasses through SV2 (10%) to the low pressure side. The piston moves to the left side and compressor load decrease. Holding Figure 14 Under this situation, all S/V are not energized. Although the oil from the left side of piston goes into the cylinder continuously, the oil in the right side of the piston is not bypassed. Therefore, the piston does not move and keeps at same position. The compressor load is constant. The control of the water temperature with stepless type Chilled water temp. Figure 15 Time Note:X Top line;x Bottom line;x set point;h Control range;y real value 13

16 Description The real value is larger than the top line between A & B. It means the required cooling capacity is increasing and the compressor needs to be loaded until the real value returns to the control range. The real value is smaller than the bottom line between C & D. It means the required cooling capacity is decreasing and the compressor needs to be unloaded until the real value returns to the control range. SV5(100%) Open SV1 Close SV2(10%) Close Load t 2 SV5(100%) Close t 1 Hold t 3 Unload SV1 Open SV2(10%) Open Figure 16 t 4 Time Open means S/V is energized Close means S.V is not energized T1,T3:Pulse time 0.5~1.5seconds T2,T4:Pause time 10~20seconds 14

17 3.2.3 The Positions of Solenoid Valves 1. LT-83/41 2. LT-20/10&LT-30/12 Figure 17 Figure 18 15

18 3.3 Compressor unloading for startup, and stop To lower the mechanical loading to compressor s parts and lower the starting current during start up. Hanbell designs for LT compressor the function of unloading startup. To ensure compressor loads steadily, please follow Figure 37 to load step by step during the whole loading process. When compressor is about to shut down, it is also required to unload. Therefore ensure the slide valve is at lowest loading position during next startup and compressor could have an unloading startup. No matter which load it is, the compressor should unload step by step to minimum loading before stop. Load% Figure 37 Compressor startup and shut down procedure Caution: 1) Hanbell strongly suggest the control logic of startup and shut down following Figure 37 2) t>60 seconds. 3) After startup, keep the minimum load for 1~3 minutes. Before shut down, keep the minimum load for 60~90 seconds. 4) After the compressor shut down, the SV1 & SV2(10%) need to be still energized, so as to ensure the slide valve be in the lowest loading position, and the next startup will be easy. Time 16

19 4. Lubricant 4.1 Lubricant Table Refrigerant R22 R404A Saturated Condensing Temp./ +30 ~ ~ +55 Saturated Suction Temp./ -60 ~ ~ -30 Discharge Temp.Protection/ Recommended Lubricant HBR-B03 HBR-B05 Specific Gravity Specific Heat 40 (Kcal/kg K) Table 3 Note: 1) Please refer to the table above to select the suitable lubricant and the refrigerant and its operation range need to be taken into consideration as well. 2) Hanbell strongly recommends do not use the lubricant which isn t certified by Hanbell since it may damage the compressor seriously. 3) This table is for LT series compressors only 4) The allowable lowest oil temperature is 20 5) After compressor stops, please turn on the oil heater. If the compressor shuts down for a long time, the oil heater doesn t need to be turned on. Please turn on the oil heater for more than 2 hours before next start up. 4.2 Oil Charging 1) Make sure the system is clean and free of welding debris before charging the oil. 2) In order to ensure no moisture in the system, Hanbell suggests cleaning the system by charging dry Nitrogen and vacuuming for several times. Try to make vacuuming time as longer as possible to eliminate moisture in the system. Note: a. Hanbell strongly recommends do not use the lubricant which isn t certified by Hanbell since it may damage the compressor seriously. b. Hanbell strongly recommends do not mix up different lubricant since it may damage the compressor seriously. Please pay attention to this issue in all future maintenance. 17

20 4.3 Oil Change Change Oil Periodically: 1)Check lubricant every 10,000 hours of continuous running. For the first operation of the compressor, it is recommended to change the oil and clean the external oil filter after running 2,000 hours. Check the system whether clean or not and then change oil every 20,000 hours or after 4 years continuous running while the system operates in good condition. 2)The oil will deteriorate if the compressor runs at high discharging temperature (Above 95 ) in the long term. Please avoid this situation, but if it s necessary to run in this condition, please shorten the intervals of oil changing Pre-cautions of Changing Oil 1) It is recommended to double check the quality of oil periodically in order to maintain the lubrication performance. 2) The lubricant absorbs moisture in the air. Avoid the situation that oil expose to air for a long time 3) It is a must to change the oil in motor burned out case, because acid material and debris may still remain inside the system. Please follow the procedures mentioned above to change the oil in the system. Check acidity of oil after 72 hours of operation and then change it again until acidity of oil returns to normal value. 4) The foreign body of the oil will block up the oil line, so it is necessary to install the oil filter in oil line. It is necessary to install the pressure sensor before and after the oil filter. If the pressure difference between these two sensors reaches 1.5 bar, the oil filter need to be changed. 5) The acidity of oil will affect directly the life of the motor, and it is recommended to change the oil when PH 6. (Please also change the filter drier at the same time to make sure the system is in dry condition.) 6) In case of motor burned out, please not only change the compressor, but also change the oil and check the condition of the oil periodically. If the acidity excesses the standard, please change it immediately and always be aware of the cleanliness and moisture content in the system. 18

21 5. System Application Note:Please consult Hanbell for parallel application and heat pump application. 5.1 Piping Design Suction and Discharge Piping Layout 1) Material and structure of suction and discharge pipe The vibration is low when the compressor is in operation so it is not necessary to use flexible joint materials for suction and discharge tubes. However, piping in other places must be flexible enough without causing any inner stress for the compressor. It is recommended to use copper tube for the suction and discharge piping in order to lower the piping vibration when the compressor is in operation. 2) The dimensions of suction and discharge piping: It is recommended to design the dimension of suction and discharge piping according to Hanbell s suggestion.(refer to ) 3) Piping for the parallel system To improve the system operation efficiency, it s necessary to reduce the gasflow resistance and consider the oil return of suction piping. The recommended piping of suction and discharge side for parallel system is shown below: Be aware of the dimension of the main pipe should not be less than the dimensions of the other pipes to make sure the pressure drops could be controlled in reasonable ranges. 19

22 Recommended discharge piping Refrigerant to oil separator Figure 19: Discharging piping for parallel system x x x Recommended suction piping Refrigerant from evaporator Picture 20: Suction piping for parallel system x x x 20

23 4) Suction Filter There is a built in suction filter in compressor, but it only functions as a final protection. Please install another suction filter(25μm)for periodically cleaning. It might be necessary to clean the suction filter for several times in initial commissioning. If the pressure drop is higher than 0.5bar,it s necessary to change the filter or clean it until the system is clean. When dismantling the filter, if the filter is damaged, please change it immediately and clean the debris left in the piping. When installation, please confirm the direction of suction filter is correct, and it is highly recommended to install service valves before and after the filter chamber for easy maintenance. Hanbell recommended suction filter layout as shown below Filter core Economizer Piping Layout 1) Dimension of Economizer A stop valve of the economizer is the standard accessory. It s recommended to design the dimension of the piping according to Hanbell s suggested value. (Refer to ) 2) Check valve for the economizer Parts of oil and refrigerant will flow back when the working condition is not stable or when economizer route is closed. In order to avoid this situation, the check valve should be installed in the economizer piping.(refer to ) 3) Filter for economizer There is a built in economizer filter for protecting the compressor from debris penetration in initial commissioning. A filter for periodical maintenance is suggested in economizer piping Minimum Pressure Valve The oil pressure difference between oil inlet and middle pressure chamber/suction pressure must reach 2.5 bar in 30 seconds after start up. When the oil 21

24 pressure difference is too low, the oil supply is not sufficient and may cause damage to compressor. So, we provide a minimum pressure valve for LT series compressor, as to achieve high enough pressure difference quickly. The minimum pressure valve should be mounted after the external oil filter. And the valve and the compressor middle pressure connector should be connected by a pipe. (As shown in the Figure below) Note:The standard minimum pressure valve size we provide to you is the same as the discharge valve. Note:Besides the standard size, other sizes are optional (refer to ) Note:LT series compressor must operate with minimum pressure valve Liquid Line Filter Dryer It will cause damage to the compressor and system even a low moisture content left in the system. It s a must to install filter drier on liquid line to keep the system dry Sight Glass with Moisture Indicator It is strongly recommended to install the sight glass with moisture indicator in order to observe the moisture content in the system. When the moisture content is high, it is necessary to change the filter dryer. 22

25 5.2 Oil Line Oil Supply The oil is supplied by the pressure difference which equals to the pressure difference between oil separator and oil injection point. The oil is injected into the bearings and compression casing, and then carried out of the compressor with discharging gas. The oil will enter the oil separator again and complete the oil circulation Lubrication and Capacity Control Modulation The oil will be injected from two oil injection connectors which supply the oil to suction and discharge bearings respectively as shown below. Besides, the connector for the lubrication of suction side bearings is also used for oil supply to capacity control system. Connector for suction bearing lubrication and capacity control Connector for discharge bearing lubrication Figure 21 Oil supply connector of discharge bearing & suction bearing 23

26 5.2.3 Liquid Injection to Chamber System In certain working condition, the compressor might need liquid injection to chamber to lower the discharge temperature and make sure the compressor will be operated properly. There are two ports for liquid injection to chamber. (As shown in the Figure 22 below) Liquid injection to chamber ( low stage) Liquid injection to chamber (high stage) Figure 22 Connectors for Liquid injection to chamber 1) Suction side(low stage) liquid injection to chamber For two-stage compressor, the pressure difference in low stage is not so high in low temperature working condition so the heat is relatively less. It is not necessary to apply the liquid injection to low stage chamber. In heat pump working condition, there will be a higher pressure difference even in low stage. According to the practical working condition, it might be necessary to apply liquid injection to chamber in low stage to make sure the compressor is in good operation condition. Remark: Hanbell recommends to use oil for liquid injection to chamber. 2) Discharge side(high stage) liquid injection to chamber It is recommended to apply liquid injection to high stage chamber in any kind of working condition. The heat generated in low stage and motor was carried to the high stage. Therefore, it is necessary to apply liquid injection in high stage for cooling. Remark: Hanbell recommends to use oil for liquid injection to chamber. 24

27 Suggestions for oil line layout Figure 23 25

28 Protection in Oil Line The normal operation of line system is critical to the reliability of compressor To ensure the capacity modulation, reliability of bearing and cooling effect, please pay attention to the point below: 1) Oil temperature The temperature of oil needs to be strictly maintained. When temperature of oil is too low: The viscosity is high and it would cause insufficient oil supply and abnormal capacity control. It would cause high liquid refrigerant content in the oil and results in oil carry over. The lubrication effect will be influenced as well. When temperature of oil is too high: The viscosity will reduce and lubrication effect is bad. Cooling effect is bad and results in high discharge temperature. In strict condition, the compressor may be damaged. High temperature will deteriorate the lubrication and influence the service life of bearing. When temperature of oil is too low: Note 1) When compressor is running the temperature of oil should be kept between20 ~60 2) When compressor stops, the oil heater needs to be switched on and keep the oil temperature above 20 3) When compressor is stopped for a long time, the oil heater can be switched off. However, the refrigerant will be dissolved in oil in long term stop and the oil can t perform properly. Before start up, the oil heater needs to be switched on to heat up the oil up to 20 Note:Hanbell can provide the oil heater(refer to ) 2) Oil filter The cleanliness of the oil is very important to screw compressor. If the welding debris or other debris enters the compressor with oil, it would cause damage in bearings or screw rotors. It is necessary to install an oil filter in oil line. It is suggested to install the oil filter after the oil It is suggested to install pressure sensor before and after the oil filter or apply pressure difference switch to detect the pressure drop after the oil filter. If the pressure drop reaches 1.5 bar, the compressor must be stopped for cleaning or replacing the oil filter. Note:Refer to Figure 23 for layout of oil filter and pressure difference switch. 3) Oil pressure difference The oil supply to compressor is depending on the oil pressure difference. To

29 ensure the oil supply, it is necessary to keep the pressure difference between oil inlet and middle pressure chamber/suction pressure above 2.5 bar. 4) Oil level protection It is suggested to install an oil level switch in oil tank or oil sump to ensure the oil supply. 5) Oil flow protection To ensure the oil supply and increase the reliability, an oil flow switch is also suggested. Note:1)Refer to Figure 23 for oil flow switch installation 2)Hanbell provides oil flow switch(refer to ) Oil Cooling System In high pressure ratio working condition, a lot of heat will be generated. Part of the heat will be moved by the oil, so it is necessary to cool down the oil. Otherwise, the oil will deteriorate and can t function well. An oil cooler can keep the temperature of oil in reasonable range and the compressor can work properly even in strict working condition. Note: 1) It is suggested to install the oil cooler near compressor. 2.) To avoid the oil enters oil separator or compressor after compressor is stopped, it is suggested to 3.) It is necessary to control the temperature of retuned oil between 40 ~60 4.) A bypass way is suggested to for ease of oil temperature control. Refer to Figure 23~25 Two suggested oil cooler layout 1) Air cooled type Figure 24 air cooled oil cooler 27

30 2) Water cooled type Figure 25 water cooled oil cooler 5.3 Liquid Injection to Motor The motor is cooled down by the gas refrigerant from low stage and economizer. However, in strict working condition, the cooling effect of gas refrigerant is not sufficient. The liquid refrigerant can be applied through the liquid injection port. When liquid refrigerant enters the chamber, it is spread by gas flow and cools down the motor evenly. Figure 26 Liquid injection to motor liquid injection to motor port Note: 1)Refer to 2.4 for the working condition that liquid injection to motor is necessary. 2)PT 100 motor temperature sensor is a standard accessory for controlling the liquid injection solenoid 28 valve.

31 5.4 Economizer System Economizer Application Cooling capacity and efficiency will increase by applying an economizer in front of expansion valve to get sub cool effect. Economizer has significant effect especially in high pressure ratio working condition. For a compound two stage compressor, the economizer is even more required. Due to its two stage design, the economizer effect is magnified. Both cooling capacity and COP increase are more significant in two stage than those of single stage compressor. The gas supplied by the economizer could reduce the discharge temperature of low stage therefore the discharge temperature at high stage can be maintained. This increases the compressor performance, reliability and widens the application limit. Two typical economizer systems: Sub Cooler With this form of operation, a heat exchanger (refrigerant sub-cooler) is used to subcooled liquid refrigerant. The sub-cooling is achieved by injecting a part of the refrigerant from the condenser through an expansion device in counter flow into the sub-cooler, which then evaporates due to the absorption of heat. The superheated vapor is pulled into the compressor at the economizer connection and mixed with the vapor, which is already compressed in low stage. The sub-cooled liquid is at condensing pressure with this form of operation, the pipeline to the evaporator does not therefore require any special features, aside from insulation. The system can be generally applied. Figure 27 shows the system with economizer, subcooler. Figure 27 Sub cooling economizer system 29

32 5.4.3 Flash Tank The liquid sub-cooling is achieved with this form of operation by reducing the boiling point pressure in an intermediate pressure vessel (flash type sub-cooler) arranged between condenser and evaporator. This physical effect leads to the cooling of the liquid down to the boiling point, due to evaporation of part of the liquid. To stabilize the pressure of the vessel, a regulator is used which at the same time controls the quantity of vapor flowing to economizer connection of the compressor. This form of operation gives the most economical thermodynamic performance due to direct heat exchanging. As the intermediate pressure is reduced to the boiling point temperature this system should only be used with flooded evaporators. Figure 28 shows the system with economizer, flash type sub-cooler. Figure 28. Flash tank economizer system 30

33 5.5 Example of System Layout Figure 29 Example of system layout 31

34 6. Motor Design 6.1 Motor Parameters and Design Motor design Standard starting method of Hanbell LT series screw compressor is Y-Δ start Y-Δ Start Y-Δ motor connects motor coil by Y connection during starting therefore reducing voltage on coils to 1/3 of input voltage and reconnects motor coil by connection after starting. By doing so, we can decrease starting current thorough voltage drop, i.e., socalled voltage-drop starting. Y-Δ motor connection method is shown in the following motor wiring diagram: In Y connection, MCM, MCS are inductive while motor leads Z,X,Y are tied together as a neutral connecting as Y fashion. A few seconds later (3~5 sec is recommended), MCM, MCS become deductive. Around 0.25 sec later, MCM, MCD are inductive, it turns out run connection. 32 Caution: Figure 30 Y-Δ connection After Y start, MCM & MCS are deductive for 0.25 sec and then MCM & MCD are inductive for Δ run. Within as transient as 0.25 sec, pseudo short circuit might occur due to inappropriate action of contactors, causing trip of compressors. When it occurs, we recommend usage of adjustable Y-Δ dedicated timer or slightly lengthen span of time for MCM, MCS deduction - MCM, MCD re-induction from 0.25 sec to 0.5 sec max directly in micro controller or PLC program. Please refer to Y-Δ shift time diagram for details. Because

35 motor is not powered during Y-Δ shift, shorter Y-Δ shift span is suggested to prevent second start due to decreased rotation speed. However, if Y-Δ shift span is too short, aforementioned pseudo short circuit might occur. I (AMP) Starting Current Full load Amper Time Y- shift time 0.25~0.5sec Figure 31. Y- transaction time diagram Y-Δ start features 1. Starting current in Y connection is 1/3 of lock rotor ampere. 2. Starting torque in Y connection is 1/3 of lock rotor torque. 3. Acceleration of motor rotor becomes smaller at full-load starting, therefore compressors require starting at partial load. Except for Y-Δ start, concerning soft start or reactance start, please kindly contact Hanbell for further information Power source requirement Power limitation Voltage limitation Long term operation:within ±5% of rated voltage Instant operation:within ±10% of rated voltage Frequency:within ±2% of rated frequency Caution: Note: In the region where the electricity power is unstable, install an additional hi-low voltage protector with ± 5% tolerance of normal voltage to ensure safe operating of the compressor. Unbalanced voltage Unbalanced voltages usually occur because of variations in the load. When the load on one or more of the phases are different from the other(s), unbalanced voltages will 33

36 appear. This can be due to different impedances, or type and value of loading in each phase. Unbalanced voltages can cause serious problems, particularly to the motor. NEMA defines voltage unbalance as follows : Percent voltage unbalance = 100 x NEMA states that poly-phase motors shall operate successfully under running conditions at rated load when voltage unbalance at the motor terminals does not exceed 1%. Furthermore, operation of a motor with over 5% unbalance is not recommended for it probably results in motor damage. Unbalanced voltages at motor terminals cause phase current unbalance ranging from 6 to 10 times the percent of voltage unbalance for a fully loaded motor. This causes motor over current resulting in excessive heat that shortens motor life, and hence, eventual motor burnout. If the voltage unbalance is great enough, the reduced torque capability might not be adequate for the application and the motor will not attain rated speed. Some of the more common causes of unbalance voltages are : Unbalanced incoming utility supply Open delta connected transformer banks Large single phase distribution transformer in the system Open phase on the primary 3-phase transformer in the distribution system Blow fuse on 3 phase bank of power factor improvement capacitors Unequal impedance in conductors of power supply wiring Unbalanced distribution of single phase loads such as lighting Unequal transformer tap settings Faults or grounds in power transformer Heavy reactive single phase loads such as welders Model MCC&LRA Start current LRA(A) / (maximum voltage deviation from average voltage) (average voltage) Maximum continues current MCC(A) LT-S-20/10 420/ LT-S-30/12 620/ LT-S-83/ / LT-H-83/ / Table 4. MCC&LRA 1) Above data based on 380V, 50Hz power supply. 2) The LRA&MCC data above has nothing to do with the refrigerant or working condition. 34

37 6.1.4 Terminal cover plate. Connection to 3 phase main power supply Warning Light Power Light Motor protector power Control relay connection Connection to discharge PTC Motor embedded PTC temperature sensor terminal Motor embedded Pt100 temperature sensor terminal Control output to liquid injection solenoid valve Temperature display module Figure 32 Terminal cover plate connection diagram Table 5. Nuts specifications for bolt on terminal cover plate Model Specs Torque (N.m) LT-S-20/10 M12 Nut 28 LT-S-30/12 M12 Nut 28 LT-S-83/41 M12 Nut 28 LT-H-83/41 M16 Nut 30 35

38 6.1.5 Terminal box An IP54 terminal box is provided as standard accessory. Please refer to below diagrams for dimensions. Figure 33 Terminal box dimension 36

39 7. Compressor installation 7.1 Open compressor wooden crate Upon receiving the compressor, please check if the crate is intact, and compressor is in good condition. Please also check accessories and documents to be consistent with order. Caution :compressor is charged with 0.5~1 bar of nitrogen before delivery. Please release the interior pressure before dismantling any parts on compressor. 7.2 Compressor Lifting When lifting the compressor, it is recommended to use a steel chain or steel cable. Make sure that chains, cables or other lifting equipments are properly positioned as shown below to protect the compressor and its accessories from damaging. Keep the compressor in horizontal position when lifting, and prevent it from crashing or falling on the ground, hitting the wall or any other accident that may damage it or its accessories. Caution: 1) Please ensure the steel cable weight load is sufficient. 2) Check the steel cable and hook before lifting, making sure there is no deform or crack to avoid accident. 3) Ensure sufficient space for lifting. Figure 34 compressor lifting 37

40 7.3 Compressor installation The installation of the compressor in the refrigeration system should be accessible and make sure that the compressor is away from the heat source to prevent heat radiation. The compressor should also be installed as close as possible to the electrical power supply for easier connection. It is necessary to keep good ventilation and low humidity condition in the site. Make sure that the frame or supporter is strong enough to prevent excessive vibration and noise while the compressor is running and must reserve enough space for compressors future maintenance work. Compressor should be installed horizontally. Meanwhile, it is recommended to install mounting pad to avoid the compressor from delivering vibrations to the piping. 1. LT-83/ LT-20/10&LT-30/12 Figure 35 mounting of LT-83/41 Figure 36 mounting of LT-20/10&LT-30/12 38

41 8. Operation and maintenance 8.1 Compressor commissioning check Check list before Start up Items Check point States or standard values 1.Compressor and accessories 2.Power system 3.Piping system 4.Protection devices 1. Oil level of external oil separator 2.Oil temperature 3.Open stop valves 4.Open motor liquid injection port(angle valve) 1. Voltage of main power 2. Voltage of control circuit 3. Insulation resistance value of the motor between phase to phase and phase to ground. 4. Power terminals and connection. 5. Grounded 6. Settings of switches, sensors and controllers. 1. Check the piping is firmed. 2. Check if there is any leakage. 1. Winding temperature 2. Discharge temperature 3. Oil level switch 4. PT100 motor temperature sensor 1. High oil level window filled. 2. Before start up, heat up the oil to 40 / heating time is around 8Hrs. 3. Open caps of stop valves to check. 4. Open cap of angle valve cap to check. 1. Main power voltage fluctuation range within ±5%. Instant voltage drop during start up is less than 10%; 2. Voltage of auxiliary power is 220V±10%. 3. Resistance value should exceed 50MΩ. 4. Power terminals are firmly fixed on terminal block and well insulated. Keep wire cables away from heat source and sharpened metal. Power terminals are fixed firmly and well insulated. Terminal screw and block are both required. 5. Installation confirmation. 6. Check original value of design. 1. Observation or manual check. 2. Apply leakage test liquid to check especially on connections and welding junctions. 1. Not active(close circuit) 2. Not active(close circuit) 3. Oil is full(close circuit) 4. Same or close to environment temperature. Table 6 Start up check list 39

42 8.1.2 Check list during operation 1)Start up compressor for 0.5~1 second. Confirm the rotation direction through monitoring suction and discharge pressure.(correct rotation direction: suction pressure goes down and discharge pressure goes up at the same time) 2)Check if the oil sight glass on external oil line is full of lubricant after start up. In case of abnormal, please check pressure difference (oil pressure differential supply), oil filter and oil line solenoid valve. 3)There will be some oil foams in the oil separator during start up but only in a short time. When working under rated working condition, the foam will disappear. Otherwise it means the system is without sufficient oil or there is oil carryover problem. 4)Compressor s operating working condition adjustment as follows: discharge temperature is 30K above condensing temperature and suction superheat within 15K. 5)The whole system should pass vibration test, especially the piping. If there is abnormal vibration and noise from compressor, please contact HANBELL. 6)Below items need to be checked every day, when compressor is operating in a long time: Compressor running data such as 3 phase voltage, current, etc. Oil temperature, oil level, all the sensors, wiring junctions, and oil line window. 7)When condensing unit operates in job site, we should beware of its complementary devices and the maintenance schedule after first commissioning. 8)To keep the lubricant viscosity normal at low ambient temperature and to ensure the function of bearing lubrication, it is suggested to keep the oil heater in the external oil separator on after compressor is turned off. This is to prepare for the next start up. 40

43 8.2 Trouble shouting table Issue Motor temperature sensor trip Defective Motor Insulation Unable to start up the motor or switch Abnormal vibration or noise Possible Reason 1. Motor over load, liquid injection solenoid valve malfunctions. 2. Motor temperature sensor switch malfunction. 3. Power system malfunction 4. Defective motor coil. 5. Liquid injection expansion valve malfunctions. 1. Power bolts condenses. 2. Defective Motor. 3. Defective power bolts. 4. Defective magnet contactor. 5. Acid in the system deteriorates the insulation 6. Long term running at high temperature cause motor insulation deterioration. 7. Frequent start up. 8. Too much water content in the refrigerant. 1. Compressor start up at full load 2. Voltage is too low or wrong. 3. Too much voltage drop, and the magnet contactor s can t induct. 4. Motor malfunction 5. Phase loss or phase reverse 6. Motor protection switch is active. 7. Wrong connection of motor terminals. 8. Timer of Y starting malfunctions. 9. Capacity of over load relay is too small. 10. Magnet contactors malfunction. 1. Bearings are damaged. 2. Liquid compression. 3. Overheated rotors touch each other or touched the chamber 4. Oil loss causes bad lubrication effect. 5. Inner parts are loose. 6. Defective piping causes resonance. 7. Objects enter the compression chamber Discharge temperature is too high 1. Suction superheat is too high. (less refrigerant volume or expansion valve malfunctions) 2. High pressure side is abnormal. (bad cooling effect, air penetrates in the system, temp. of cooling water is too high, cooling water flow is too less, heat exchange capability of condenser is bad.) 3. Compression ratio is high without liquid injection. 41

44 Time of reverse rotation is too long System low pressure alarm System high pressure alarm Oil flow alarm Discharge temperature is too low Oil carry over 4. Bearings are damaged. Rotors friction. 5. Oil loss or oil level is too low. 6. Suction check valve malfunctions. 1. Stop action is not set in control logic. 2. Piston of suction check valve is blocked, and can t close. 1. Lack of refrigerant 2. Evaporator frosts seriously, and affects the heat exchange. 3. Opening of expansion valve is too small. 4. Suction filter is blocked by ice or debris. 5. Capacity of evaporator is too small. 6. Wrong setting of the low pressure protection. 1. Too much refrigerant. 2. Condenser is blocked by debris, dust or penetrated by air. 3. Discharge temperature is too high. 4. Expansion valve is blocked by ice or debris. 5. The capacity of condenser is too small. 6. Wrong setting of high pressure protection. 1. Oil flow switch malfunctions. 2. The condensing pressure is not built up. 3. Oil line blocked. 4. Oil line solenoid valve malfunctions. 1. Liquid compression. 2. Temperature of returned oil is too low. 3. Opening of liquid line expansion valve is too large. 4. Opening of economizer expansion valve is too large. 1. Discharge temperature is too low. 2. Demister of oil separator malfunctions. 3. Oil temperature is too low(oil heater is not switched on) 4. Liquid compression. 5. Opening of economizer expansion valve is too large. 42

45 9. Dimensions 9.1 LT-S-20/10 No Cable box NAME Suction shut-off valve ECO shut-off valve 3" 1 1/2" Discharge shut-off valve 2" Solenoid valve Solenoid valve Oil hydraulic cylinder Solenoid valve Solenoid valve Oil inlet connector Oil inlet connector Liquid injection connector 10% SV1 100% SV2 75% SV4 50% SV3 1/4"Flare 1/4"Flare 3/8"Flare SPECIFICATION No. NAME SPECIFICATION 13 Three-warAngle valve 1/4"Flare 14 Angle valve 1/4"Flare 15 Safety Valve 1/2" 16 Suction filter 17 Check Valve 18 Liquid(oil or refrigerant) injection connector 1/4"Flare Item Date Modification Changer Approver Model Name LT-S-2010 Compressor outline 上海漢鐘精機股份有限公司

46 9.2 LT-S-30/12 No Suction shut-off valve ECO shut-off valve Cable box NAME 3" 1 1/2" Discharge shut-off valve 2" Solenoid valve Solenoid valve Oil hydraulic cylinder Solenoid valve Solenoid valve Oil inlet connector Oil inlet connector Liquid injection connector 10% SV1 100% SV2 75% SV4 50% SV3 1/4"Flare 1/4"Flare 3/8"Flare SPECIFICATION No. NAME SPECIFICATION 13 Three-warAngle valve 1/4"Flare 14 Angle valve 1/4"Flare 15 Safety Valve 1/2" 16 Suction filter 17 Check Valve 18 Liquid(oil or refrigerant) injection connector 1/4"Flare Item Date Modification Changer Approver Model Name LT-S-3012 Compressor outline 上海漢鐘精機股份有限公司 1

47 9.3 LT-S-83/41 No. NAME SPECIFICATION 1 2 Suction shut-off valve ECO shut-off valve 5" 2" 3 Cable box 4 Discharge shut-off valve 2-1/2" 5 6 Solenoid valve Solenoid valve 10% SV1 100% SV2 7 Oil hydraulic cylinder 8 Solenoid valve 75% SV Solenoid valve Oil inlet connector 50% SV3 5/8"Flare 11 Oil inlet connector 3/8"Flare 12 Liquid injection connector 1/4" No. 13 Oil inlet connector 3/8"Flare Liquid (oil or refrigerant) 14 3/8"Flare injection connector Three-way Angle valve Angle valve Nut NAME 1/4"Flare 1/4"Flare Liquid injection connector 1" Refrigerant service valve 1/4"Flare ECO check valve 2" 21 Discharge check valve 2 1/2" SPECIFICATION 5/8"Flare,motor cooling Item Date Modification Changer Approver Model Name LT-S-8341 Compressor outline 上海漢鐘精機股份有限公司 2

48 9.4 LT-G-20/10 No. NAME SPECIFICATION 1 Suction shut-off valve 3" 2 ECO shut-off valve 1 1/2" 3 Cable box 4 Discharge shut-off valve 2" 5 Solenoid valve 10% SV1 6 Solenoid valve 100% SV2 7 8 Oil hydraulic cylinder Solenoid valve 75% SV4 9 Solenoid valve 50% SV3 10 Oil inlet connector 1/4"Flare 11 Oil inlet connector 1/4"Flare 12 Liquid injection connector 3/8"Flare Motor-assistant cooling No. NAME SPECIFICATION 13 Angle valve 1/4"Flare 14 Angle valve 1/4"Flare 15 Safety Valve 1/2" (optional) 16 Suction filter 17 Check Valve Liquid(oil or refrigerant) 18 injection connector 1/4"Flare Item Date Modification Changer Approver Model Name LT-G-2010 Compressor outline 上海漢鐘精機股份有限公司 3

49 9.5 LT-G-30/12 No. NAME SPECIFICATION 1 Suction shut-off valve 3" 2 ECO shut-off valve 1 1/2" 3 Cable box 4 Discharge shut-off valve 2" 5 Solenoid valve 10% SV1 6 Solenoid valve 100% SV2 7 8 Oil hydraulic cylinder Solenoid valve 75% SV4 9 Solenoid valve 50% SV3 10 Oil inlet connector 1/4"Flare 11 Oil inlet connector 1/4"Flare 12 Liquid injection connector 3/8"Flare Motor-assistant cooling No. NAME SPECIFICATION 13 Angle valve 1/4"Flare 14 Angle valve 1/4"Flare 15 Safety Valve 1/2" (optional) 16 Suction filter 17 Check Valve 18 Liquid(oil or refrigerant) injection connector 1/4"Flare Item Date Modification Changer Approver Model Name LT-G-3012 Compressor outline 上海漢鐘精機股份有限公司 4

50 9.6 LT-G-83/41 No. 1 NAME Suction shut-off valve flage 5" SPECIFICATION No. 13 NAME Angle valve 1/4"Flare SPECIFICATION ECO shut-off valve flage Discharge shut-off valve flage Solenoid valve Solenoid valve 2" 2-1/2" 10% SV1 100% SV Connect Nut Angle valve Connect 1/4"Flare 1" 1/4"Flare 1/4"Flare 6 Oil hydraulic cylinder 7 Solenoid valve 75% SV Solenoid valve Oil inlet connector Liquid(oil or refrigerant) injection connector Oil inlet connector Liquid(oil or refrigerant) injection connector 50% SV3 5/8"Flare 3/8"Flare 3/8"Flare 3/8"Flare Item Date Modification Changer Approver Model Name LT-G-8341 Compressor outline 上海漢鐘精機股份有限公司 5

51 9.7 LT-S-83/41-H No. NAME SPECIFICATION 1 2 Suction shut-off valve ECO shut-off valve 5" 2", 经济器接口 3 Cable box 4 Discharge shut-off valve 2-1/2" 5 6 Solenoid valve Solenoid valve 10% SV1 100% SV2 7 Oil hydraulic cylinder 8 Solenoid valve 75% SV Solenoid valve Oil inlet connector 50% SV3 5/8"Flare 11 Oil inlet connector 3/8"Flare 12 Liquid injection connector 3/8"Flare No Oil inlet connector Liquid injection connector Angle valve Angle valve Nut NAME Liquid injection connector 3/8"Flare 5/8"Flare 1/4"Flare 1/4"Flare 1" 1/4"Flare Refrigerant service valve 1/4"Flare ECO check valve 2" SPECIFICATION Item Date Modification Changer Approver Model Name LT-S-8341-H Compressor outline 上海漢鐘精機股份有限公司 6

52

53 10. Accessories Hanbell provides or designs standard or optional accessories for various kind of applications Accessory list Standard Accessory list Optional Item Description Q ty Standard/optional 1. Motor protector-int69hby 1 2. Suction stop valve 1 3. Discharge stop valve 1 4. Economizer stop valve 1 5. Suction flange bushing 1 6. Discharge flange bushing 1 7. Economizer flange bushing 1 8. Suction check valve 1 9. Discharge check valve Economizer check valve Suction filter(suction side) Suction filter(middle pressure side) Pressure difference switch(manual reset) Mounting pad Economizer muffler Minimum pressure valve HBR-B03 Oil 17. Flow switch 1

54 10.2 Accessory for gas refrigerant line Stop valve For ease of maintenance, it is suggested to install suction, discharge, and economizer stop valve. Dimension and spec are shown below: Spec Dimension (mm) 1

55 5 stop valve Spec Dimension (mm) *Parameters of stop valve Maximum working pressure Pressure test(air pressure) Temperature range 28 bar 35 bar -70~150 *Application reference Size Model Suction Discharge economizer LT-20/10 3" 2" 1 1/2" LT-30/12 3" 2" 1 1/2" LT-83/41 5" 2 1/2" 2" 2

56 Note :If the specs of flange bushings are not specified in order, Hanbell will provide standard parts. Please refer to the table below for other specs Flange bushing Standard flange bushing Model Discharge Suction Economizer Steel Copper Steel Copper Steel Copper LT- 20/ / /8 1 1/2 1 5/8 LT- 30/ / /8 1 1/2 1 5/8 LT- 83/41 2 1/2 2 5/ / /8 Model Position Material of piping Dimension A B C D E 1 5/8" /4" " Copper 2 1/8" Discharge LT- 2 1/2" /10 2 5/8" LT- 1 1/2" /12 Steel 2" ' Suction Copper 2 1/8" /8" /2"

57 2 5/8" " /8" LT- 83/41 Economizer Discharge Suction Economizer Steel Copper Steel Copper Steel Copper Steel Copper steel 2" /2" " /2" /8" /4" " /8" /4" /2" /8" /4" " /8" /2" /8" /8" /2" " /2" /8" /8" " " " /8" /4" " /8" /2" /8" /2" "

58 Check valve Horizontal type check valve is provided in discharge side and economizer. When compressor is stopped, the teflon valve plate will be pushed by spring force to close the opening. This reduces the time of reverse rotation to protect the compressor. 1)Economizer check valve(horizontal type) Item valve Lead Description body clip spring plate nut rod plate plate Spec Dimension: mm A B C D E F G H I /

59 2)Discharge check valve(horizontal type) Item valve Lead Description body clip spring gasket nut rod plate plate Spec Dimension: mm A B C D E F G H I J 1 1/ / Note: the size of check valve correspond to those of stop valve. Refer to

60 Minimum pressure valve Minimum pressure valve is useful in cold start condition. During the cold start period, because the system s condensing temperature is still low, the discharge pressure will stay at a quite low level which means the pressure differential between discharge and suction side will not be enough for compressor to act normally. Under such working condition, compressor might have difficulties to load itself. Oil supply to bearings and internal cooling might be not enough which will cause severe damage to those moving parts in the end. With minimum pressure valve, the pressure differential can be built shortly after the start up, so the capacity control and oil supply to those moving parts won t be a problem. Therefore, the compressor protection can be achieved. In addition to protection function, it can also act as check valve to reduce the reverse running time after compressor s stopping. Connect to compressor middle pressure side To condenser Pressure after valve Pressure before valve From oil separator outlet Spec 1.5" 2" 2.5" 3" 4" 5" 6" Pressure difference to open Maximum working pressure Temperature range Pressure drop 3.6±0.3Bar 28Bar <120 <0.1Bar 7

61 底部视图 规格 Spec 1-1/2" 2" 2-1/2" 3" 4" Dimension: 尺寸 mm A B C D E F G H I J K L M16* M16* M16* M20* M20* 底部视图 Spec 规格 5" 6" Dimension: mm 尺寸 A B C D E F G H I J

62 10.3 Oil line accessory Oil flow switch An oil flow switch should be installed in the oil returned line from external oil separator to protect compressor. Spec: Type Dimension Connector 3/8 flow switch DN10 3/8 5/8 flow switch DN16 5/8 1 flow switch DN25 1 Outline of oil flow switch Parameters: Maximum working pressure: 25bar Maximum working temperature:100 Protection class: IP65 Maximum current: 5A Maximum voltage: 250VAC Minimum protection flow:0.7l/min Maximum pressure drop at maximum flow: 0.01bar 9

63 External oil filter The oil filter is 300 mesh and can be reused by cleaning. Outline of external oil filter Spec A B C D 3/8 89 mm 340 mm 200 mm 55 mm 5/ Structure Spec of external oil filter 1.bolts 2.cover plate 3.gasket 4.spring 5.filter core 6.O-ring 7.oil inlet 8.body 9.oil outlet 10.angel valve 10