Hanbell LT-S Series User manual

LT-S-(L) Technical manual
Contents
1. Overview..........................................................................................................................3
2. Product Specification......................................................................................................4
2.1 Nomenclature...........................................................................................................4
2.2 Product Line............................................................................................................4
2.3 Compressor specification table ..............................................................................4
2.4 Operating range graph...........................................................................................6
3. Construction & Functions..............................................................................................8
3.1 Design Features .......................................................................................................8
3.2 Capacity modulation system ..................................................................................8
3.2.1 Step type capacity modulation system.........................................................10
3.2.2 Stepless type capacity modulation system...................................................14
3.2.3 The Location of the Solenoid Valves............................................................19
4. Lubricant.......................................................................................................................21
4.1 Lubricant Specification ........................................................................................21
4.2 The Replacement of Lubricant............................................................................22
4.3.1 Oil Change Schedule.....................................................................................22
4.3.2 Pre-cautions for changing oil........................................................................22
5. SystemApplication........................................................................................................24
5.1 Piping Design.........................................................................................................24
5.1.1 Suction and Discharge Piping Layout.........................................................24
5.1.2 Economizer Piping Layout...........................................................................26
5.1.3 Minimum pressure valve ..............................................................................26
5.1.4 Liquid Line Filter Dryer...............................................................................27
5.1.5 Sight Glass with Moisture Indicator............................................................27
5.2 Oil Line...................................................................................................................28
5.2.1 Oil Supply ......................................................................................................28
5.2.2 Lubrication and Capacity Control Modulation..........................................28
5.2.3 Compressor chamber injection system........................................................28
5.2.4 Protection in Oil Circuit...............................................................................29
1）Oil temperature.......................................................................................................29
2）Oil filter....................................................................................................................30
3）Oil pressure differential..........................................................................................31
4）Oil level protection..................................................................................................31
5.2.5 Oil cooling system..........................................................................................31
1）Air cooling type .......................................................................................................33
2）Water cooling type.........................................................................................33
3）Refrigerant oil cooling ..................................................................................34
5.3 Motor Liquid Injection Cooling...........................................................................34
5.4 Economizer System...............................................................................................35
5.4.1 Economizer System with Sub Cooler...........................................................35
5.4.2 Economizer System with Flash Type Subcooler.........................................36

LT-S-(L) Technical manual
5.5 Recommended System Layout.............................................................................38
Figure 5-14. High Temperature Heat Pump Recommend System Layout......................38
6. Electrical Design............................................................................................................39
6.1 Electrical parameters and design.........................................................................39
6.1.1 Y-Δ Start.........................................................................................................39
6.1.2 Power requirements......................................................................................40
6.1.3 MCC&LRA ...................................................................................................41
7. Compressor Installation ...............................................................................................45
7.1 Open compressor wooden crate...........................................................................45
7.2 Compressor Lifting...............................................................................................45
7.3 Compressor installation........................................................................................46
8. Operation and Maintenance.........................................................................................48
8.1 Compressor commissioning check.......................................................................48
1.1.1 Check list before Start ..................................................................................48
8.1.2 Check list during operation..........................................................................49
8.2 rouble shooting table.............................................................................................50
9. Dimensions.....................................................................................................................53
10. Accessories.....................................................................................................................60
10.1 Accessory List........................................................................................................60
10.2 Accessory for gas refrigerant line........................................................................61
10.2.1 Shut-off valve.................................................................................................61
10.2.2 Tube................................................................................................................62
10.2.3 Check valve....................................................................................................64
10.2.4 Minimum pressure valve ..............................................................................66
10.3 Oil line accessory...................................................................................................68
10.3.1 Oil flow switch...............................................................................................68
10.3.2 Oil Line Solenoid Valve.................................................................................70
10.3.3 Oil Pressure Differential Switch...................................................................70
10.4 ElectricalAccessory ..............................................................................................71
10.4.1 INT69 HBY Diagnose Protection module ...................................................71
10.4.2 300Woil heater...............................................................................................74
10.5 Other accessories...................................................................................................77
10.5.1 Cushion ..........................................................................................................77

LT-S-(L) Technical manual
1. Overview
For conventional single-stage screw compressors, Its evaporation temperature
can only reach -40~-50°C during freezing application. If you want to break this
application limitation, it is required to use two-stage compressor or cascade system.
Meanwhile, the working condition of high pressure ratio brings problems to the
traditional single-stage compressors during compression process, such as excessive
gas leakage and high exhaust temperature etc., which leads to low efficiency and poor
reliability when it is working is such harsh conditions.
The compound two-stage compressor well solves above problems. Compared
with the two-stage compressors or cascade system, the compund two-stage
compressors occupy less space and the system is easy to control, so it's more
efficiency and reliable.
LT Series compound two-stage compressor’s evaporation temperature can be as
low as -60~-65°C , Its full load evaporating temperature can be -25°C, LT-S-L Series
compound two-stage low temperature compressor is based on the LT-S series which
modified the internal structure and optimized the motor matching to increase the
compressor full-load evaporation temperature to -10 °C, So that LT-S-L series can
meet the requirements of industrial refrigeration、quick freezing tunnel and freezing
library without pre-cooling
For above reasons, Therefore The Shanghai Hanbell Precise Machinery Co., Ltd.
developed the LT series high temperature compressors. High efficiency and reliability
under big pressure differential and compression ratio working condition is the main
demand in designing. It is a elitist product which accumulates Shanghai Hanbell's rich
technology and extensive application experience. It can be widely used in many
industries such as high temperature hot water, central heating and so on.

LT-S-(L) Technical manual
2. Product Specification
2.1 Nomenclature
Low temperature products codification
Application field
LT-S-XX/XX
R22 Application of refrigeration
LT-S-XX/XX-R&U
R404A&R507 Application of refrigeration
LT-S-XX/XX-L
R22 Application of refrigeration
LT-S-XX/XX-L-R&U
R404A&R507 Application of refrigeration
Table 2-1.LT series low temperature compressor nomenclature
2.2 Product Line
Table 2-2.LT low temperature series product specification
★
Low temp. products codification
Model range
LT-S-XX/XX
LT-S-XX/XX- R&U
LT-20/10~LT-83/41
LT-S-XX/XX-L
LT-S-XX/XX-L- R&U
LT-20/10、LT-45/20~LT-83/41
2.3 Compressor specification table
0
200
400
600
800
1000
LT-20/10
LT-30/12
LT-45/20
LT-55/25
LT-65/32
LT-83/41
Displacement m3/h
LT low temperature series product specification

LT-S-(L) Technical manual
Model
Compressor
Low
pressure
stage
High
pressure
stage
Rotat
ion
speed
50Hz
r/min
Capacity control
Lubrication type
Noise
Displaceme
nt
Displacem
ent
Freezing/
Refrigeration
LT-S
Freezing/
Refrigeration
LT-S-L
50Hz
50Hz
m3/h
m3/h
Step type
Stepl
ess
type
dB
LT-20/10
224
99
2950
10%/50%
100%
10%
~
100
%
Pressure differential oil supply
81
81
LT-30/12
316
137
81
/
LT-45/20
450
207
83
84
LT-55/25
551
257
84
85
LT-65/32
651
313
10%/50%
75%/100%
86
88
LT-83/41
840
396
87
89
Model
Quality
Motor
Strength test
Type
Startin
g
Voltag
e
(V)
50Hz
Insulation level
Protection
Kg
bar
Freezing/
Refrigeratio
n LT-S
Freezing/
Refrigerati
on LT-S-L
Freezing/
Refrigeratio
n LT-S
Freezing/
Refrigeration
LT-S-L
LT-20/10
598
620
3
phase
2
pole
squirr
el
cage
induc
tion
moto
r
Star
delta
380
Lev
el F
PTC+
PT100
(NTC
optional)
35
LT-30/12
620
/
LT-45/20
1158
1200
LT-55/25
1195
1230
LT-65/32
1395
1450
LT-83/41
1430
1490
Table 2-3.LT series compressor specification

LT-S-(L) Technical manual
2.4 Operating range graph
图2-1. R22 运行范围图

LT-S-(L) Technical manual
图2-2.R404A 运行范围图

LT-S-(L) Technical manual
3. Construction & Functions
3.1 Design Features
1）Starting load
Starting with light load; its starting load is similar to ordinary single stage
compressor, so as to avoid greater impact on power grid.
2）Motor cooling channel
Excellent motor cooling channel design which ensures the high efficiency of the
compressor, while realizing the reliable cooling of the motor, so that the compressor
can operate in a very wide range, and a more extensive scope of application.
3）integrated design of system parts
Pre-installed medium pressure check valves, shut off valves and economizer
filters that ensure reliable protection of compressors and simplify customer system
configuration.
4）Motor temperature visualization
The embedded temperature sensor of motor, PT100, PT1000 and NTC, are
optional, which can directly read the motor temperature to control the motor
temperature.
3.2 Capacity modulation system
LT series screw compressor is equipped with 3/4 step capacity modulation
system or continuous (stepless) capacity modulation system.
Both of the two capacity modulation systems are composed of slide valve, piston
rod, piston cylinder and piston. As shown in Figure 3-1 below.
When the spool is fully in contact with the suction side, the screw rotor is in
full-load suction state, at which time the working volume of the compressor is
maximized. As the spool is separated from the suction side, it moves toward the
exhaust side. A bypass cavity is formed between the slider and the suction side. Its
presence causes the compressed gas in this range to be bypassed directly to the low
pressure, and the actual suction volume of the screw rotor is reduced. The more the
slide valve moves toward the exhaust side, the smaller the actual suction volume of
the compressor will be. And the system cooling capacity will also reduce
The slide valve is driven by the pressure differential among the internal capacity
modulation system.
The lubricant comes from the external oil separator and passes through the oil
filter then enters into the oil inlet port of the compressor, and at last divided to both

LT-S-(L) Technical manual
sides of the piston. As a result, the piston can be controlled by discharging the high
pressure lubricant at one side to low pressure, letting it flow to the low pressure side
so that the slide valve will move with the piston to realize the loading and unloading
of the compressor.
The purpose of the piston spring is to push the piston to its initial position (min.
load position), so as to realize the automatic unloading start. It not only reduces the
mechanical impact on the compressor's moving parts, but also reduces the electrical
current during compressor start up.
Stepless capacity control, solenoid valve(SV1:unloading, SV3:50%, SV5:100%)
is controlled by a micro controller or a thermal switch to adjust the piston smoothly to
stably control cold output. If the oil filter capillary or solenoid valve of the capacity
modulation system don't work properly, it will cause the capacity modulation system
to be abnormal and fail.
Figure 3-1.Capacity Modulation System

LT-S-(L) Technical manual
3.2.1 Step type capacity modulation system
1）Step type control logic
Y: Energize the solenoid valve N: Do not energize the solenoid valve
LT-83/41& 65/32
Capacity modulation system
SV1:Unload
(NC)
SV2:10%
(NC)
SV3:50%
(NC)
SV4:75%
(NC)
SV5:100%
(NC)
100% load
N
N
N
N
Y
75% load
Y
N
N
Y
N
50% load
Y
N
Y
N
N
10% load（startup/stop）
Y
Y
N
N
N
LT-20/10&30/12
LT-45/20&55/25
Capacity modulation system
SV1:unload
(NC)
SV2:10%
(NC)
SV3:50%
(NC)
/
SV5:100%
(NC)
100% load
N
N
N
/
Y
50% load
Y
N
Y
/
N
10% load（startup/stop）
Y
Y
N
/
N
Table 3-1. Step Type Capacity Modulation Control Logic
2）Step type capacity modulation graph
Figure 3-2. Step Type Capacity Modulation

LT-S-(L) Technical manual
3）Step type control logic description
10% load
Figure 3-3. 10% Load
When starting up the
compressor, SV1(unload) &
SV2 (10%) need to be
energized to make the piston
keep at the 10% position(left
side)
In this state, the high
pressure oil passes through
SV1(unload) then goes to the
right side of the piston. At the
same time, the oil from left
side of the piston passes through SV2 (10%) then discharge to the low pressure side.
By doing so, the piston can be held at the 10% load position.
★Note: 10% load is for start up only. Running the compressor at 10% load for a long
time is not recommended.
50% load
At this time, the
capacity adjustment solenoid
valves SV1 (unload) and
SV3 (50%) are active.
Under 50% load,
SV1(unload) &SV3 (50%)
are energized.
In this state, the high
pressure oil passes to the left
side of the piston
continuously. At the same
time, the oil passes through
SV1 (unload) then goes to
the right side of the piston.
fig3-3.10%负载

LT-S-(L) Technical manual
If the piston is at the left side of the 50% hole (the loading is less than 50%), the
oil at the right side of the piston will pass through SV3 (50%) and discharge to the
low pressure side then the piston will move to right side until the position blocks the
50% hole. Thus the compressor is loaded to 50% smoothly.
Vice versa, if the piston is at the right side of the 50% hole (the loading is more
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 blocks
the 50% hole. Thus the compressor is loaded to 50% smoothly.
75% Load
Under 75% load, SV1
（unload ）&SV4 (75%)
are energized.
The logic of 75% load is
similar to that of 50%. The
piston can be held around
75% position by 75% hole
to make the compressor
run under 75% load.
Figure 3-5.75% Load
100%Load
Under 100% load, SV5
(100%) is energized. In this state,
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.
fig3-4.50%负载
fig3-6.100% Load

LT-S-(L) Technical manual
4）Step type capacity modulation and water temperature control
Figure 3-7.Step type capacity modulation and water temperature control
★Note: T & T' should be adjusted by system designer’s experience and practical application.
50%
Time
启动
Set point + 2T
Set point + T
Set point
Set point–T'
Stop
Storage
temperature
50%
75%
100%
t1 t2
75%
(66
%)
10%
1~3
min
10%
60~90 sec

LT-S-(L) Technical manual
3.2.2 Stepless type capacity modulation system
Stepless type is suitable when the refrigeration system needs to achieve precise
control of cooling capacity.
1）Stepless type control logic
N: Do not energize the solenoid valve
LT series
Capacity
modulation system
SV1: unload
(NC)
SV2:10%
(NC)
SV3:50%
(NC)
SV5:100%
(NC)
Load
N
N
N
Pulse activating
Unload
Pulse activating
N
Stay energized
N
Keep load state
N
N
N
N
10% load
（start/shutdown）
Stay energized
Stay energized
N
N
Table 3-2. Stepless Type Capacity Modulation Control Logic 50%~100%

LT-S-(L) Technical manual
2）Stepless type capacity modulation graph
Figure 3-8.Stepless Type Capacity Modulation
3）Stepless type control logic description
In stepless type capacity modulation system, the oil keeps going to the left side
of the piston. The oil bypass in the left side of the piston is controlled by SV3 (50%).
The oil inlet in the right side of the piston is controlled by SV1 (unload) 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.
Through the three solenoid valves, the cooling capacity can be controlled at any
position from 50%~100%, so through periodical adjustment of SV1、SV3、SV5, the
energy output can controlled stably.
★Note: SV2(10%) can only be used for machine start and stop. Don't run the
machine at 10% load for long time once the machine is started. It shall be switched to
load model directly.
The stepless type capacity modulation system shall be connected to the micro
controller(optional), eg. PLC etc. in order to control the system at the target working
condition.

LT-S-(L) Technical manual
Load
During load process, the SV5 (100%) adopts pulse activating, and the rest
solenoid valve are not energized.
In this kind of
situation, 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 will
continue to move to the
right side and the
compressor complete
load process.
Figure 3-9. Load
Unload
During unload process,
the SV2(50%) stays active,
and SV1 (unload) adopts pulse
activating, and the rest
solenoid valve are not
energized.
The high pressure oil
continues to go to the left side
of the piston and goes into the
right side of the piston passing
through SV1(unload).
Through SV3(50%), it
Figure 3-10. Unload bypasses to the low pressure side, so that the piston
continues to move to the left side, and the compressor will load to 50% piston.

LT-S-(L) Technical manual
Keep load state
Figure 3-11. Keep Load State
During this process, all S/V are not energized. The high pressure oil coming
continues to go to the left side of the piston. The left side oil inlet of the piston
SV1(unload) and SV5(100%) are closed to keep the oil amount in the right side of the
piston. The piston will not be able to move and stay at its original position, so that the
compressor capacity will not change as well.

LT-S-(L) Technical manual
Stepless type capacity modulation and water temperature control
Below picture shows the load control of single compressor in the application of
stepless type capacity modulation.
Figure 3-12. Stepless Type Capacity Modulation
★Note：X′Upper Limit；X〞Lower Limit；X Set Point；H Control Range；Y Actual valve
Description:
The actual water temperature exceeds the upper limit between A & B. It
means the compressor ought to unload until the actual value is within 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.
Figure 3-13. Solenoid Valve Action Intervals-Stepless Type
★Note：For detail stepless type capacity modulation control logic, please refer to
Table 3-2
Load/Unload functions between A and B, C and D.
Energized：Solenoid valve is powered and energized
Close：Solenoid valve is not energized
T1，T3：Pulse time 0.5~1.5 seconds
T2，T4：Pause time 10~20 seconds
Time

LT-S-(L) Technical manual
3.2.3 The Location of the Solenoid Valves
1）LT-83/41&LT-65/32
Figure 3-14.LT-83/41&LT-65/32 solenoid valve location
2）LT-20/10&LT-30/12&LT-45/20&LT-55/25
Figure 3-15.LT-20/10&LT-30/12&LT-45/20&LT-55/25 Solenoid Valve Location

LT-S-(L) Technical manual
3）Compressor unloading for startup, and stop
To decrease the mechanical loading to compressor’s parts and decrease the starting
current during start up. Hanbell designs for LT compressor the function of unloading
startup. To ensure compressor loads steadily, please follow Figure 3-16 to load step by
step during the whole loading process.
When compressor is about to shut down, it is also required to unload to ensure that
the slide valve is at lowest loading position during next startup and compressor could
have an unloading startup. Thus Hanbell requires no matter what load condition of the
compressor is, it should be unloaded step by step till minimum load before stop
according to below Figure 3-16.
Figure 3-16. Compressor Startup and Stop Process
Caution：
1）After startup, keep the minimum load for 10 seconds. Before shut down, keep the
minimum load for 30 seconds(Time can be set to 10~60seconds).
2）After startup, when the pressure difference between high pressure and middle
pressure is less than 3.5bar, the compressor shall be run at 10% load at low
pressure stage. Don't load and open ECO.
3）t=30 seconds(Time can be set to 30~60seconds).
4）After the compressor shut down, the SV1 (unload) & SV2(10%) need to be still
energized for 3 minutes, so as to ensure the compressor can still at min load
position at next startup.
5）Hanbell strongly recommends that the compressor start-up and shutdown control
logic shall refer to above graph. For detail information
please refer to the regulations written in LT-S Control Requirements.